Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Nat Commun ; 15(1): 2126, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459105

RESUMO

Ocean warming and acidification, decreases in dissolved oxygen concentrations, and changes in primary production are causing an unprecedented global redistribution of marine life. The identification of underlying ecological processes underpinning marine species turnover, particularly the prevalence of increases of warm-water species or declines of cold-water species, has been recently debated in the context of ocean warming. Here, we track changes in the mean thermal affinity of marine communities across European seas by calculating the Community Temperature Index for 65 biodiversity time series collected over four decades and containing 1,817 species from different communities (zooplankton, coastal benthos, pelagic and demersal invertebrates and fish). We show that most communities and sites have clearly responded to ongoing ocean warming via abundance increases of warm-water species (tropicalization, 54%) and decreases of cold-water species (deborealization, 18%). Tropicalization dominated Atlantic sites compared to semi-enclosed basins such as the Mediterranean and Baltic Seas, probably due to physical barrier constraints to connectivity and species colonization. Semi-enclosed basins appeared to be particularly vulnerable to ocean warming, experiencing the fastest rates of warming and biodiversity loss through deborealization.


Assuntos
Biodiversidade , Invertebrados , Animais , Oceanos e Mares , Peixes , Temperatura , Água , Ecossistema , Aquecimento Global
2.
Environ Sci Pollut Res Int ; 25(23): 22689-22701, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29851016

RESUMO

Since the end of the 1980s, white shrimps (Palaemon longirostris) from the Gironde estuary have exhibited exoskeletal malformations, mainly involving cephalothorax, rostrum, scaphocerites and uropods. An 8-month study was carried out in 2015. Each month, 200 individuals were sampled and examined for exoskeletal malformations. Temporal variations in malformation frequency were noted, particularly during the breeding period, along with decreases in the size of non-deformed shrimps related to the appearance of juveniles in breeding sites, and high mortality among deformed shrimps. A significant increase in proportions of deformed shrimp was observed, relating particularly to the size (and therefore the age) of individuals. No significant difference was found between shrimp proportions with different numbers of malformations (one to four) for a fixed size class, nor was there any variation in proportions within different size classes for a fixed number of malformations. This would appear to indicate that the number of malformations is acquired and new malformations do not seem to appear during the life cycle, except for the smallest (youngest) shrimps. The malformation spectrum showed no significant differences between the biggest and smallest individuals for the different malformation associations, except for those involving cephalothorax, rostrum and uropods. This would suggest that some malformation associations lead to a higher mortality rate in shrimps subjected to them, due to greater impairment of feeding and/or swimming behaviour. Multiple component analysis of the different types of malformation showed correlations between exoskeletal pieces (rostrum and cephalothorax) and appendixes (scaphocerites and uropods). Regarding metal contamination in shrimp, no significant difference was highlighted between deformed and non-deformed shrimps. Organic pollutants were not measured in tissues. Certain herbicides such as metolachlore and chlortoluron were detected at high concentrations in the Gironde estuary during the breeding period corresponding to the higher occurrence of exoskeletal malformations.


Assuntos
Exoesqueleto/anormalidades , Metais Pesados/análise , Palaemonidae/anatomia & histologia , Poluentes Químicos da Água/análise , Exoesqueleto/efeitos dos fármacos , Animais , Feminino , França , Metais Pesados/metabolismo , Palaemonidae/efeitos dos fármacos , Estações do Ano , Poluentes Químicos da Água/metabolismo
3.
Sci Total Environ ; 639: 465-475, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29800840

RESUMO

Assessing ecological health of aquatic ecosystems is crucial in the current context of biodiversity loss to guide and prioritize management actions. Although several fish-based indices were developed to assess the ecological status of estuarine ecosystems, they do not provide guidance on the causal responses of communities to disturbances. The functional trait-based approach provides an understanding of how human disturbance affects the composition of biological and ecological traits in assemblages, as well as their consequences for ecosystem functioning. Here, we evaluate the responses of fish assemblages to human disturbance in 30 French estuaries using several taxonomic and functional indices (e.g. diversity, evenness or redundancy). We tested whether these indices can provide additional information on the human impacts and health of assemblages that are not reflected by the ecological indicator (fish-based index ELFI). Results indicated that high values of local human disturbances were associated to a decrease in fish abundance, decrease in species richness and reduced functional redundancy, whereas taxonomic and functional evenness increased. In contrast, the functional richness remained stable suggesting that the functional traits of species removed by stressors were maintained by more tolerant species. Indeed, we found that the local disturbances mainly resulted in a decrease in the proportions of small benthic species feeding on macro-invertebrates, which were dominant in the studied estuaries. Some functional alterations were detected by the fish-based index, but the decline of functional redundancy was not reflected, highlighting a serious concern for management. Indeed, the abrupt collapse of functional redundancy in response to local disturbances can decrease the ability of assemblages to maintain certain species traits in the face of future environmental disturbance, including climate change. From a management perspective, the application of such functional redundancy measure in monitoring programs can help stakeholders identify sensitive areas where conservation efforts need to be planned.


Assuntos
Biodiversidade , Monitoramento Ambiental , Estuários , Peixes , Animais , Ecologia , Ecossistema , Humanos
4.
Sci Rep ; 7(1): 17611, 2017 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-29242556

RESUMO

The impact of species loss on ecosystems functioning depends on the amount of trait similarity between species, i.e. functional redundancy, but it is also influenced by the order in which species are lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of vulnerable species (with high propensity of extinction when facing threats) causes a greater functional alteration than random extinction. Our results indicate that the functional redundancy tended to increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the three systems, some combinations of functional traits are supported by non-redundant species, ii) rare species in rivers and estuaries support singular functions not shared by dominant species, iii) the loss of vulnerable species can induce greater functional alteration in rivers than in lakes and estuaries. Overall, the functional structure of fish assemblages in rivers is weakly buffered against species extinction because vulnerable species support singular functions. More specifically, a hotspot of functional sensitivity was highlighted in the Iberian Peninsula, which emphasizes the usefulness of quantitative criteria to determine conservation priorities.


Assuntos
Biodiversidade , Ecossistema , Peixes/fisiologia , Animais , Conservação dos Recursos Naturais/métodos , Estuários , Europa (Continente) , Extinção Biológica , Água Doce , Lagos , Rios
5.
Breastfeed Med ; 12: 210-217, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28326807

RESUMO

OBJECTIVE: This study aimed to determine the relationship between perceived insufficient milk supply (PIMS) and actual insufficient milk supply (AIMS) and the relative contributions of physiological and psychosocial variables on both PIMS and AIMS of first-time breastfeeding mothers. PARTICIPANTS AND METHODS: Data were collected among 123 breastfeeding mothers at a Canadian, French-speaking maternal care hospital. Birth events, breastfeeding practices, infant and maternal capacities, and PIMS and AIMS were collected at 48 hours after birth, postnatal weeks 2 and 6. RESULTS: No significant relationship was found between PIMS and AIMS. Maternal breastfeeding self-efficacy and number of feeds were related to PIMS at week 2, and skin-to-skin contact at birth and number of feeds were related to AIMS as measured by 24-hour milk production at week 2. CONCLUSION: Maternal breastfeeding self-efficacy impacts PIMS. Interventions should be directed to increase maternal confidence in breastfeeding, which in turn influences breastfeeding duration.


Assuntos
Aleitamento Materno/psicologia , Leite Humano/metabolismo , Mães/psicologia , Período Pós-Parto/psicologia , Adulto , Canadá , Aconselhamento Diretivo , Feminino , Humanos , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Lactação , Estudos Longitudinais , Mães/educação , Período Pós-Parto/fisiologia , Autoimagem , Autoeficácia
6.
Sci Total Environ ; 542(Pt A): 383-93, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26520263

RESUMO

Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context.


Assuntos
Conservação dos Recursos Naturais/métodos , Estuários , Pesqueiros/estatística & dados numéricos , Peixes/fisiologia , Animais , Monitoramento Ambiental , Dinâmica Populacional
7.
West J Nurs Res ; 37(3): 376-93, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24221955

RESUMO

Smoking cessation strategies are barely discussed in nursing education programs, even though initial education shapes how future professionals practice their profession. The aim of this research is to describe the practices, attitudes, and beliefs of nursing educators of Quebec with regard to smoking cessation strategies in initial nursing education. A descriptive design was chosen along with an online questionnaire. A total of 278 educators (20.8%) participated in the survey. Although educators recognize the importance of incorporating smoking cessation strategies into their teaching practice, they allocate an average of only one hour per year to the topic. Tobacco use is addressed mostly in terms of risk factors, with little focus on how to help patients quit. The perceived obstacles are related to false beliefs and a lack of knowledge. The results of this study demonstrate the need to raise educators' awareness of the importance of incorporating smoking cessation strategies into classroom teaching.


Assuntos
Atitude do Pessoal de Saúde , Docentes de Enfermagem , Enfermeiras e Enfermeiros/psicologia , Abandono do Hábito de Fumar/métodos , Ensino/métodos , Currículo , Feminino , Humanos , Masculino , Quebeque , Inquéritos e Questionários
8.
Sante Publique ; 26(1): 45-53, 2014.
Artigo em Francês | MEDLINE | ID: mdl-24893514

RESUMO

INTRODUCTION: Basic nursing education has a major impact on the future professional practices of nurses. Nurses must be adequately trained to perform health promotion activities, such as smoking cessation. However, nurses play only a minor role in this field. The objective of this research was to describe the smoking cessation content in basic nursing programmes in Quebec. METHODS: A simple descriptive mixed design (quantitative and qualitative) study was conducted among nursing programme administrators in Quebec, using a validated online questionnaire. RESULTS: On average, the time devoted to smoking cessation was reported to be less than one hour per year, essentially concerning the physiological and pathophysiological factors of tobacco consumption, while nursing professional assessment and counselling in smoking cessation were almost non-existent. CONCLUSION: The results confirm the need to increase and improve the time and content devoted to smoking cessation in the basic nursing education curriculum. It is also important to structure basic training courses so to improve knowledge, attitudes, and skills of future nurses in order to influence their role in smoking cessation in their future professional practice.


Assuntos
Currículo , Educação em Enfermagem , Abandono do Hábito de Fumar , Pessoal Administrativo , Humanos , Quebeque , Inquéritos e Questionários
9.
Rech Soins Infirm ; (116): 57-69, 2014 Mar.
Artigo em Francês | MEDLINE | ID: mdl-24830223

RESUMO

INTRODUCTION: Research results demonstrate a decrease in cigarette smoking when preventive professional interventions are routinely carried out. Literature reports that 30% of hospital nurses assess their patient smoking habits. The objective of the present study is to compare, on medical and surgical units, the effectiveness of three strategies (interactive educational session, recall, and both together) to a control group, on the number of nursing interventions pertaining to cessation of cigarette smoking. Research design is experimental with group randomisation. Pre and post strategy multi-measurements (at 1 and 3 months) are sought from nursing staff (69), patients and patient charts (351). Results show that nursing staff assesses cigarette smoking habits for only 35.7% of the patients, and their intent to stop smoking only of the time. Results show that the educational strategy increases the number of nursing interventions during a short period (1 month), and decreases perception of barriers to tobacco counselling. Impact of recall could not be assessed as it was not introduced as planned. CONCLUSION: Considering modest results from the strategies, the interactive educational sessions shows a short- term effect on the nursing staff's interventions.


Assuntos
Recursos Humanos de Enfermagem no Hospital , Padrões de Prática em Enfermagem , Abandono do Hábito de Fumar/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Quebeque
11.
Rech Soins Infirm ; (112): 36-45, 2013 Mar.
Artigo em Francês | MEDLINE | ID: mdl-23671985

RESUMO

UNLABELLED: Nurses in hospitals are not active in smoking cessation because of certain beliefs and attitudes. Beliefs and attitudes must be measured for changing practice in quitting smoking. The objective is to develop and validate a questionnaire on smoking cessation practices of nurses in hospitals. METHODOLOGY: A methodological study was conducted to construct a questionnaire (n = 118) according to the theory of planned behaviour, to validate by four experts, for reliability and validation of instruments constructs (n = 38; n = 29; n = 157). RESULTS: An initial questionnaire on practices in smoking cessation was built according to the beliefs of a convenience sample of 118 nurses. Validation of experts was conducted, and the questionnaire obtained an index of content validation (ICV) of 0.94. Subsequently, after two convenience samples (n = 38; n = 29) and a random sample (n = 157), the questionnaire obtained reliability, measured by Cronbach's alpha ranging in 0.697 and 0.93 1. Finally, moderately high correlations (0.406 to 0.569) were obtained between concepts. CONCLUSION: A reliable and valid questionnaire in French is available to measure smoking cessation practices.


Assuntos
Atitude do Pessoal de Saúde , Recursos Humanos de Enfermagem no Hospital , Abandono do Hábito de Fumar , Inquéritos e Questionários , Humanos , Quebeque
12.
Clin Nurs Res ; 22(3): 310-36, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23291315

RESUMO

The objective of this research was to study influence of birth routines on mother-infant interaction at Day 4. The present research is part of a longitudinal study where mother-infant pairs were randomized by infant location and apparel. We intended to assess mother-infant interaction from videos filmed at Day 4. A protocol for the assessment/coding of the affective quality of maternal behaviors indicative of early mother-infant interaction was developed and interculturally validated. Results were compared with birth randomization, as to explain impact of birth practices. Findings indicate that separation and swaddling at birth interfered with mother-infant interaction during a breastfeeding session at Day 4; these mothers significantly demonstrated more roughness in their behaviors with their infants at Day 4. Results also show evidences of a sensitive period for separation after birth. Implications are to encourage immediate and uninterrupted skin-to-skin contact at birth, and rooming-in during postpartum, as recommended in World Health Organization/UNICEF Ten Steps for Successful Breastfeeding.


Assuntos
Relações Mãe-Filho , Pele , Aleitamento Materno , Feminino , Humanos , Recém-Nascido , Gravidez
13.
Sci Total Environ ; 409(19): 3680-6, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21719074

RESUMO

Polychlorinated biphenyls (PCBs) and organochlorine pesticides like dichloro-diphenyl-trichloroethane (DDTs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin and trace elements (Cd, Cu, Se, Pb, Zn and Hg) were analysed in the muscle of European sea bass (Dicentrarchus labrax) sampled in Atlantic coastal regions near several important European river mouths (Gironde, Charente, Loire, Seine and Scheldt). High contamination levels were measured in the muscles of European sea bass sampled in the coastal regions near those river mouths (e.g. Σ ICES PCB=133-10,478 µg kg(-1) lw and Hg=250-2000 µg kg(-1) dw). The Scheldt and the Seine are still among the most contaminated estuaries in Europe. Each region presented their specific contamination patterns reflecting different sources due to the input of the respective rivers. As fish and fishery products are the main contributors of the total dietary intake of organochlorinated pollutants, regular consumption of European sea bass with the reported contamination levels may represent a significant exposure route for the general human population.


Assuntos
Bass/metabolismo , Monitoramento Ambiental , Hidrocarbonetos Clorados/metabolismo , Metais Pesados/metabolismo , Bifenilos Policlorados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Europa (Continente) , Hidrocarbonetos Clorados/análise , Metais Pesados/análise , Músculos/química , Bifenilos Policlorados/análise , Medição de Risco , Poluentes Químicos da Água/análise
14.
Dev Biol ; 263(2): 296-307, 2003 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-14597203

RESUMO

In order to gain insights into the evolution of gastrulation mechanisms among vertebrates, we have characterized a Brachyury-related gene in a lamprey, Lampetra fluviatilis, and in a chondrichthyan, Scyliorhinus canicula. These two genes, respectively termed LfT and ScT, share with their osteichthyan counterparts prominent expression sites in the developing notochord, the tailbud, but also a transient expression in the prechordal plate, which is likely to be ancestral among vertebrates. In addition, the lamprey LfT gene is transcribed in the endoderm of the pharyngeal arches and the epiphysis, two expression sites that have not been reported thus far in gnathostomes, and, as in the chick, in the differentiating nephrotomes. Since Brachyury expression in nascent mesoderm and endoderm is highly conserved among vertebrates as well as cephalochordates, we have used this marker to identify these cell populations during gastrulation in the dogfish. The results suggest that these cells are initially present over the whole margin of the blastoderm and are displaced during gastrulation to its posterior part, which may correspond to the site of mesoderm and endoderm internalization. These data provide the first molecular characterization of gastrulation in a chondrichthyan. They indicate that gastrulation in the dogfish and in some amniotes shares striking similarities despite the phylogenetic distance between these species. This supports the hypothesis that the extensively divergent morphologies of gastrulae among vertebrates largely result from adaptations to the presence of yolk.


Assuntos
Cação (Peixe)/embriologia , Proteínas Fetais , Gástrula/fisiologia , Lampreias/embriologia , Proteínas com Domínio T/genética , Animais , Movimento Celular , Cação (Peixe)/metabolismo , Feminino , Duplicação Gênica , Lampreias/metabolismo , Mesoderma/metabolismo , Filogenia
15.
Gene Expr Patterns ; 2(1-2): 99-103, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12617845

RESUMO

We report the embryonic expression in the lamprey Lampetra fluviatilis of Tbx1, the main candidate gene involved in DiGeorge/velo-cardio-facial syndrome (DGS/VCFS). From the end of neurulation to stage 26, Tbx1 becomes progressively expressed in all developing pharyngeal arches, as they form. Transcripts are mainly restricted to the mesodermal core and to the posterior pharyngeal endoderm, excluding ingressing neural crest cells. They are also present in the otic vesicle, in a ventral and posterior location. From a later stage (stage 27) onwards, additional expression domains in the head mesenchyme, later contributing to labial muscle precursors, and in the cloacal region, become visible. The comparison of these data with those reported in the chick and the mouse indicates a high conservation of Tbx1 expression in the pharyngeal arches among vertebrates.


Assuntos
Lampreias/genética , Proteínas com Domínio T/genética , Sequência de Aminoácidos , Animais , Síndrome de DiGeorge/genética , Feminino , Hibridização In Situ , Lampreias/embriologia , Lampreias/metabolismo , Masculino , Mesoderma/metabolismo , Dados de Sequência Molecular , Filogenia , Proteínas com Domínio T/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...