Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Ambio ; 37(2): 86-92, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18488550

RESUMO

Eutrophication is an ongoing process in most parts of the Baltic Sea. This article reports on the changes during recent decades of several eutrophication-related variables in the open sea areas surrounding Finland (wintertime nutrient concentrations, wintertime nutrient ratios, and summer time chlorophyll alpha concentrations at the surface). The sum of nitrate- and nitrite-nitrogen ([NO3+NO2]-N) was observed to increase nearly fourfold in the Northern Baltic Proper and the Gulf of Finland and almost double in the Bothnian Sea from the 1960s until the 1980s or 1990s. The increase was followed by a decrease, which was modest in the two former subregions. Phosphate-phosphorus (PO4-P) concentrations followed a similar pattern in the Northern Baltic Proper (threefold increase and subsequent slight decrease) and Bothnian Sea (30% increase and subsequent decrease), but increased throughout the study in the Gulf of Finland, with the present concentration being threefold to the measurements made in the early 1970s. The PO4-P concentration decreased throughout the study in the Bothnian Bay. Silicate-silicon (SiO4-Si) concentrations decreased 30-50% from the early 1970s to the late 1990s and increased 20-40% thereafter in the Northern Baltic Proper, the Gulf of Finland, and the Bothnian Sea. Chlorophyll alpha showed an increase of over 150% in the Northern Baltic Proper and the Gulf of Finland from the 1970s until the early 2000s. In the Bothnian Sea the chlorophyll alpha concentration increased more than 180% from the late 1970s until the late 1990s, and decreased thereafter. According to these long-term observations, the Gulf of Finland and Northern Baltic Proper show clear signs of eutrophication, which may be emphasized by hydrographical changes affecting the phytoplankton communities and thus the algal biomass.


Assuntos
Clorofila/análise , Compostos Inorgânicos/análise , Fósforo/análise , Água do Mar/química , Estações do Ano
2.
Ecol Lett ; 10(4): 290-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17355568

RESUMO

Hutchinson's paradox of the plankton inspired many studies on the mechanisms of species coexistence. Recent laboratory experiments showed that partitioning of white light allows stable coexistence of red and green picocyanobacteria. Here, we investigate to what extent these laboratory findings can be extrapolated to natural waters. We predict from a parameterized competition model that the underwater light colour of lakes and seas provides ample opportunities for coexistence of red and green phytoplankton species. To test this prediction, we sampled picocyanobacteria of 70 aquatic ecosystems, ranging from clear blue oceans to turbid brown peat lakes. As predicted, red picocyanobacteria dominated in clear waters, whereas green picocyanobacteria dominated in turbid waters. We found widespread coexistence of red and green picocyanobacteria in waters of intermediate turbidity. These field data support the hypothesis that niche differentiation along the light spectrum promotes phytoplankton biodiversity, thus providing a colourful solution to the paradox of the plankton.


Assuntos
Cianobactérias/isolamento & purificação , Água Doce , Luz , Modelos Biológicos , Água do Mar , Biodiversidade , Contagem de Colônia Microbiana , Cor , Cianobactérias/fisiologia , Ecossistema , Fitoplâncton/isolamento & purificação , Fitoplâncton/fisiologia
3.
PLoS One ; 11(1): e0147085, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26751965

RESUMO

This paper puts forward a framework for probabilistic and holistic cost-effectiveness analysis to provide support in selecting the least-cost set of measures to reach a multidimensional environmental objective. Following the principles of ecosystem-based management, the framework includes a flexible methodology for deriving and populating criteria for effectiveness and costs and analyzing complex ecological-economic trade-offs under uncertainty. The framework is applied in the development of the Finnish Programme of Measures (PoM) for reaching the targets of the EU Marine Strategy Framework Directive (MSFD). The numerical results demonstrate that substantial cost savings can be realized from careful consideration of the costs and multiple effects of management measures. If adopted, the proposed PoM would yield improvements in the state of the Baltic Sea, but the overall objective of the MSFD would not be reached by the target year of 2020; for various environmental and administrative reasons, it would take longer for most measures to take full effect.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Conservação dos Recursos Naturais/economia , Análise Custo-Benefício , Ecossistema , Monitoramento Ambiental/economia , União Europeia , Finlândia , Modelos Estatísticos , Oceanos e Mares , Probabilidade
4.
Mar Pollut Bull ; 74(1): 311-9, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23849951

RESUMO

The European seas are under anthropogenic pressures impacting the state of water quality, benthic habitats and species. The EU Marine Strategy Framework Directive (MSFD) requires the Member States to assess the impacts of pressures and make a programme of measures leading to good environmental status (GES) by 2020. This study presents a method for assessing the quantity and distribution of anthropogenic impacts on benthic habitats in the Baltic Sea by using spatial data of human pressures and benthic habitats. The southern sub-basins were more extensively impacted than the northern sub-basins. Over the entire sea area, deep sea habitats were more impacted than shallower infralittoral and circalittoral habitats. Sand and coarse sediments were the seabed types relatively most impacted in the Baltic Sea scale. A comparison against tentative thresholds for GES showed that in the sub-basin scale only one third of the habitat types was in GES.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Poluentes da Água/análise , Biologia Marinha
5.
Mar Pollut Bull ; 60(5): 642-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20006361

RESUMO

The Helsinki Commission (HELCOM) Baltic Sea Action Plan, adopted by the coastal countries of the Baltic Sea and the European Community in November 2007, is a regional intergovernmental programme of measures for the protection and management of the marine environment explicitly based on the Ecosystem Approach. The Action Plan is structured around a set of Ecological Objectives used to define indicators and targets, including effect-based nutrient input ceilings, and to monitor implementation. The Action Plan strongly links Baltic marine environmental concerns to important socio-economic fields such as agriculture and fisheries and promotes cross-sectoral tools including marine spatial planning. Due to complementarities with the European Union (EU) Marine Strategy Framework Directive, the Action Plan is in essence a pilot for this process without neglecting the important role of the Russian Federation - the only Baltic coastal country not a member of the EU.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Biologia Marinha/métodos , Países Bálticos , Conservação dos Recursos Naturais/legislação & jurisprudência , União Europeia , Pesqueiros/legislação & jurisprudência , Pesqueiros/métodos , Geografia , Cooperação Internacional , Biologia Marinha/legislação & jurisprudência , Oceanos e Mares , Projetos Piloto
6.
J Pharm Sci ; 98(10): 3676-90, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19177516

RESUMO

The aim of this study was to determine, whether interactions between a drug and hydrophobic polymer matrix are present, and if so, how they affect the drug release. In addition, the most important formulation parameters, for example porosity or structure of the tablet, which have the greatest impact on drug release, were defined. Six different drug compounds, that is allopurinol, acyclovir, metronidazole, paracetamol, salicylamide and theophylline, were used in different formulations with hydrophobic starch acetate (DS 2.7) as a matrix forming polymer. Results indicate that the formulation parameters describing directly or indirectly the structure of the matrix, such as porosity, compaction force and the particle size fraction of the filler-binder, have the strongest impact on drug release. The contribution of drug property based variables is not as high as formulation parameters, but they cannot be overlooked. The contribution of water solubility and dissolution rate of the compound are obvious, but there are other significant parameters, which describe the hydrophobic and hydrophilic regions of the molecule, that also affect the drug release. This can be seen especially with the salicylamide: compound which appears to have a strong and sufficiently high hydrophobic region that interacts with starch acetate and impairs the drug release.


Assuntos
Preparações Farmacêuticas/química , Polímeros/química , Amido/análogos & derivados , Acetilação , Análise de Variância , Sequência de Carboidratos , Química Farmacêutica , Cromatografia Gasosa , Excipientes , Análise dos Mínimos Quadrados , Dados de Sequência Molecular , Tamanho da Partícula , Relação Quantitativa Estrutura-Atividade , Solubilidade , Amido/química , Comprimidos
7.
Appl Environ Microbiol ; 71(8): 4364-71, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16085826

RESUMO

To investigate the responses of Baltic Sea wintertime bacterial communities to changing salinity (5 to 26 practical salinity units), an experimental study was conducted. Bacterial communities of Baltic seawater and sea ice from a coastal site in southwest Finland were used in two batch culture experiments run for 17 or 18 days at 0 degrees C. Bacterial abundance, cell volume, and leucine and thymidine incorporation were measured during the experiments. The bacterial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes with sequencing of DGGE bands from initial communities and communities of day 10 or 13 of the experiment. The sea ice-derived bacterial community was metabolically more active than the open-water community at the start of the experiment. Ice-derived bacterial communities were able to adapt to salinity change with smaller effects on physiology and community structure, whereas in the open-water bacterial communities, the bacterial cell volume evolution, bacterial abundance, and community structure responses indicated the presence of salinity stress. The closest relatives for all eight partial 16S rRNA gene sequences obtained were either organisms found in polar sea ice and other cold habitats or those found in summertime Baltic seawater. All sequences except one were associated with the alpha- and gamma-proteobacteria or the Cytophaga-Flavobacterium-Bacteroides group. The overall physiological and community structure responses were parallel in ice-derived and open-water bacterial assemblages, which points to a linkage between community structure and physiology. These results support previous assumptions of the role of salinity fluctuation as a major selective factor shaping the sea ice bacterial community structure.


Assuntos
Ecossistema , Bactérias Gram-Negativas/crescimento & desenvolvimento , Gelo , Água do Mar/microbiologia , Cloreto de Sódio/farmacologia , Contagem de Colônia Microbiana , DNA Bacteriano/análise , DNA Ribossômico/análise , Eletroforese/métodos , Finlândia , Genes de RNAr , Bactérias Gram-Negativas/efeitos dos fármacos , Leucina/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Timidina/metabolismo
8.
Int J Syst Evol Microbiol ; 55(Pt 2): 555-568, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15774625

RESUMO

Diversity and ecological features of cyanobacteria of the genus Nodularia from benthic, periphytic and soil habitats are less well known than those of Nodularia from planktonic habitats. Novel benthic Nodularia strains were isolated from the Baltic Sea and their morphology, the presence of gas vacuoles, nodularin production, gliding, 16S rRNA gene sequences, rpoB, rbcLX and ndaF genes, and gvpA-IGS regions were examined, as well as short tandemly repeated repetitive sequence fingerprints. Strains were identified as Nodularia spumigena, Nodularia sphaerocarpa or Nodularia harveyana on the basis of the size and shape of the different types of cells and the presence or absence of gas vacuoles. The planktonic strains of N. spumigena mostly had gas vacuoles and produced nodularin, whereas the benthic strains of N. sphaerocarpa and N. harveyana lacked gas vacuoles and did not produce nodularin (except for strain PCC 7804). The benthic strains were also able to glide on surfaces. In the genetic analyses, the planktonic N. spumigena and benthic N. sphaerocarpa formed monophyletic clusters, but the clusters were very closely related. Benthic strains determined as N. harveyana formed the most diverse and distant group of strains. In addition to phylogenetic analyses, the lack of the gvpA-IGS region and ndaF in N. sphaerocarpa and N. harveyana distinguished these species from the planktonic N. spumigena. Therefore, ndaF can be considered as a potential diagnostic tool for detecting and quantifying Baltic Sea bloom-forming, nodularin-producing N. spumigena strains. The data confirm that only one morphologically and genetically distinct planktonic species of Nodularia, N. spumigena, and at least two benthic species, N. sphaerocarpa and N. harveyana, exist in the Baltic Sea.


Assuntos
Sedimentos Geológicos/microbiologia , Nodularia/classificação , Nodularia/genética , Água do Mar/microbiologia , Toxinas Bacterianas/metabolismo , DNA Bacteriano/análise , DNA Ribossômico/análise , Genes de RNAr , Dados de Sequência Molecular , Nodularia/fisiologia , Nodularia/ultraestrutura , Peptídeos Cíclicos/biossíntese , Fenótipo , Filogenia , Plâncton/classificação , Plâncton/genética , Proteínas/genética , RNA Ribossômico 16S/genética , Vacúolos/metabolismo
9.
Appl Environ Microbiol ; 68(11): 5296-303, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12406717

RESUMO

Colony-forming cyanobacteria of the genus Aphanizomenon form massive blooms in the brackish water of the Baltic Sea during the warmest summer months. There have been recent suggestions claiming that the Baltic Sea Aphanizomenon species may be different from Aphanizomenon flos-aquae found in lakes. In this study, we examined variability in the morphology and 16S-23S rRNA internal transcribed spacer (ITS) sequences of A. flos-aquae populations along a salinity gradient from a string of lakes to a fjord-like extension of the Baltic Sea to the open Baltic Sea. Morphological differences among the populations were negligible. We found that the Baltic Sea was dominated (25 out of 27 sequences) by one ITS1-S (shorter band of ITS 1 [ITS1]) genotype, which also was found in the lakes. The lake populations of A. flos-aquae tended to be genetically more diverse than the Baltic Sea populations. Since the lake ITS1-S genotypes of A. flos-aquae are continuously introduced to the Baltic Sea via inflowing waters, it seems that only one ITS1 genotype is able to persist in the Baltic Sea populations. The results suggest that one of the ITS1-S genotypes found in the lakes is better adapted to the conditions of the Baltic Sea and that natural selection removes most of the lake genotypes from the Baltic Sea A. flos-aquae populations.


Assuntos
Cianobactérias/classificação , DNA Intergênico/análise , Variação Genética , Microbiologia da Água , Cianobactérias/genética , DNA Bacteriano/análise , DNA Intergênico/genética , Biologia Marinha , Filogenia , RNA Ribossômico/análise , RNA Ribossômico/genética , Cloreto de Sódio
10.
Twin Res ; 7(5): 421-9, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15527657

RESUMO

Weight discordance is very rare in monozygotic (MZ) twin pairs; when found, however, such pairs are advantageous in the search for either environmental or epigenetic causes and consequences of obesity. We analyzed the growth patterns of young adult MZ pairs discordant and concordant for obesity. Screening 5 consecutive birth cohorts (1975-1979) of 22- to 27-year-old Finnish twins (the FinnTwin16 study), we found 14 obesity discordant (Body Mass Index [BMI] difference > or = 4 kg/m2) MZ pairs out of 658. Ten pairs participated in clinical studies. Nine concordant pairs (BMI difference < or = 2 kg/m2) were examined as controls. Lifetime measured heights and weights recorded in hospitals and health centers were traced manually. Height development was similar in all the co-twins of both groups. The weight differences between the co-twins of the discordant pairs began to emerge at 18 years leading to an average discordance of 16.4 kg, 5.6 kg/m2 (p for both = .005) at 25.7 years. The heavier co-twin weighed 221 g (p = .066), 1.0 kg/m2 (p = .01) more already at birth than the leaner, but the differences waned by 6 months of age and reappeared only after adolescence. Both the leaner and the heavier co-twins of the discordant pairs weighed more than expected by the singleton reference values (Cole et al., 1998) after 8 years. The concordant co-twins, on the other hand, grew similarly and after 6 months, their mean growth was not distinguishable from the singleton patterns. Young adulthood represents a critical period of gaining weight irrespective of genetic background in this twin sample.


Assuntos
Tamanho Corporal , Gêmeos Monozigóticos , Adolescente , Adulto , Índice de Massa Corporal , Pesos e Medidas Corporais , Criança , Pré-Escolar , Doenças em Gêmeos/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Obesidade/epidemiologia , Aumento de Peso/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA