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1.
Ecology ; 99(3): 761, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29281144

RESUMO

Size, growth, and density have been studied for North American Pacific coast sea urchins Strongylocentrotus purpuratus, S. droebachiensis, S. polyacanthus, Mesocentrotus (Strongylocentrotus) franciscanus, Lytechinus pictus, Centrostephanus coronatus, and Arbacia stellata by various workers at diverse sites and for varying lengths of time from 1956 to present. Numerous peer-reviewed publications have used some of these data but some data have appeared only in graduate theses or the gray literature. There also are data that have never appeared outside original data sheets. Motivation for studies has included fisheries management and environmental monitoring of sewer and power plant outfalls as well as changes associated with disease epidemics. Studies also have focused on kelp restoration, community effects of sea otters, basic sea urchin biology, and monitoring. The data sets presented here are a historical record of size, density, and growth for a common group of marine invertebrates in intertidal and nearshore environments that can be used to test hypotheses concerning future changes associated with fisheries practices, shifts of predator distributions, climate and ecosystem changes, and ocean acidification along the Pacific Coast of North America and islands of the north Pacific. No copyright restrictions apply. Please credit this paper when using the data.

2.
Ecol Appl ; 3(2): 331-350, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-27759312

RESUMO

Detecting the environmental impacts of human activities on natural communities is a central problem in applied ecology. It is a difficult problem because one must separate human perturbations from the considerable natural temporal variability displayed by most populations. In addition, most human perturbations are generally unique and thus unreplicated. This raises the problem of deciding whether observed local effects are due to human intervention or to the natural differences in temporal patterns that often occur among different sites. These problems can be successfully addressed with the Before-After/Control-Impact (BACI) sampling design, in which Impact and Control sites are sampled contemporaneously and repeatedly in periods Before and After the human perturbation of interest. In the present case, we use this design to examine the ecological effects of the cooling water discharge from a coastal nuclear power plant in southern California. The results suggest some general lessons about the process of impact assessments that are applicable in many ecological contexts. In systems where plants and animals are long-lived and recruit sporadically, the rates of change in density are often so low that sampling more than a few times per year will introduce serial correlations in the data. As a result, for studies of few years duration, few samples will be taken. A small sample size means that the tests of the assumptions underlying the statistical analyses, e.g., independence and additivity, will have low power. This injects uncertainty into the conclusions. Small sample size also means that the power to detect any but very large effects will be low. In our study, sampling periods of 2- yr both Before and After the impact were not long enough to detect a halving or doubling of populations at the impact site. We concluded that there were significant environmental impacts because: (1) the effect size was generally very large (°-75%); (2) there was a consistent pattern among species; (3) there were two Impact sites, and effects were larger at the site nearest the discharge; (4) the observed effects accorded with physical changes that could be linked with the source of impact; and (5) a number of alternative mechanisms, unrelated to the source of impact, were examined and rejected. Relative to control populations, there were statistically significant reductions in density of snails, sea urchins, and sea stars, all of which occurred primarily on rocky substrates. All of the reductions were larger at the Impact station about 0.4 km from the discharge than at a second Impact station 1.4 km away. The most plausible mechanisms for the declines seem to be linked to the turbidity plume created by the power plant and the resultant increase in suspended inorganic and organic materials (+46% at the Impact site nearest the discharge). Any associated flux of fine particles on rocks would have deleterious effects on many of the hard benthos. Populations of two filter-feeding species, a gorgonian coral and a sponge, showed relative increases in density. Although the increase in populations of filter feeders could be related to the ingestion, killing, and discharge of tons of plankton by the cooling system, an alternative natural mechanism was also considered reasonable. Monitoring studies or relatively long-lived organisms will often have low power to detect ecologically significant changes in density. The present study of kelpforest organisms extended over nearly 6 yr, yet the resulting statistical tests generally had power of <30% to detect a doubling or halving in density at a significance level of .05. In such a community it would be a mistake to conclude that there were no significant ecological effects based on conventional hypothesis tests. Unless there is a willingness to accept the fact that changes in natural populations on the order of 50% will often go undetected, the standards and types of evidence used to demonstrate environmental impacts must be changed.

3.
Ecol Appl ; 1(3): 258-267, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27755774

RESUMO

Many regions of the California, USA, outer continental shelf are subject to ongoing and planned oil and gas development, but there is very limited information on the recolonization and recovery of deep-water (e.g., 60-300 m) hard-substrate communities that may be affected by these activities. The purpose of this study was to summarize existing information on these communities, thereby aiding regulatory agencies and the scientific community in assessing potential impacts, and to determine whether additional studies may be necessary. Impacts from anchoring and increased sedimentation (e.g., from discharges of drilling muds and cuttings) are particularly likely. Sedimentation effects can be natural of human-induced, but habitat disruption from anchoring has few natural parallels. Disturbances from anchoring and sedimentation generally produce Type 1 and Type 2 patches (sensu Sousa 1985, Connell and Keough 1985), respectively. Recolonization and recovery of these patches in deep-water environments are expected to vary in accordance with current models of succession (i.e., inhibition, facilitation, and tolerance). However, inhibition responses likely will predominate in Type 1 patches, particularly high-relief (e.g., > 1 m) areas, where regrowth from the margins often is possible from sheet-like or mound-like forms such as those represented by many sponge taxa. In contrast, recovery of Type 2 patches, particularly low-relief (e.g., <1 m) areas, also may be influenced primarily by inhibition responses, but the relative lack of nearby colonizers suggests greater numbers of species interactions in accordance with facilitation and tolerance models. This is due to the greater stochastic component associated with recolonization by long-range larval dispersers. Recovery is expected to require a few to several years to accomplish for these deep-water hard-substrate communities. This is based on estimated times for recovery of slow-growing, generally long-lived taxa, such as some vase sponges and anemones characteristic of many high-relief areas, and the uncertainties of long-range recruitment coupled with variable sediment movement in many low-relief areas.

4.
J Colloid Interface Sci ; 358(1): 73-80, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21421221

RESUMO

In this paper, a novel method based on the electrospray technique has been developed for preparation of quantum dot (QD)-encoded microspheres for the fist time. By electrospraying the mixture of polymer solution and quantum dots solution (single-color QDs or multi-color QDs), it is accessible to obtain a series of composite microspheres containing the functional nanoparticle. Poly(styrene-acrylate) was utilized as the electrospray polymer materials in order to obtain the microsphere modified with carboxyl group on the surface. Moreover, to test the performance of the QD-encoded microsphere in bioapplication, it is carried out that immunofluorescence analysis between antigens of mouse IgG immobilized on the functional microsphere and FITC labeled antibodies of goat-anti-mouse IgG in experiment. To the best of our knowledge, this is the first report of QD-encoded microspheres prepared by electrospray technology. This technology can carry out the one-pot preparation of different color QD-encoded microspheres with multiple intensities. This technology could be also suitable for encapsulating other optical nanocrystals and magnetic nanoparticles for obtaining multifunctional microspheres. All of the results in this paper show that the fluorescence beads made by electrospray technique can be well applied in multiplex analysis. These works provide a good foundation to accelerate application of preparing microspheres by electrospray technique in practice.


Assuntos
Técnicas Eletroquímicas/métodos , Fluorimunoensaio/métodos , Imunoglobulina G/análise , Microesferas , Pontos Quânticos , Animais , Fluoresceína-5-Isotiocianato , Cabras , Camundongos , Poliestirenos/química
5.
Nano Lett ; 7(12): 3803-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17975946

RESUMO

We report a multilayer solution-processed blue light-emitting diode based on colloidal core/shell CdS/ZnS nanocrystal quantum dots (QDs). At a low-operating voltage of 5.5 V, the device emits spectrally pure blue radiation at 460 nm with a narrow full-width-at-half-maximum bandwidth of 20 nm and high brightness up to 1600 cd/m2. Broad-band, long-wavelength emission from the polymer components and deep traps in the QDs are minimized to less than 5% of the total emission.


Assuntos
Cor , Nanopartículas Metálicas , Cádmio , Coloides , Eletroquímica , Luz , Luminescência , Soluções , Enxofre , Zinco
6.
Blood ; 107(1): 132-4, 2006 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-16160004

RESUMO

Hepatic veno-occlusive disease (VOD) is a common complication of high-dose chemotherapy associated with bone marrow transplantation. While the pathogenesis of VOD is uncertain, plasminogen activator inhibitor-1 (PAI-1) has emerged as a diagnostic marker and predictor of VOD in humans. In this study, we investigated the role of PAI-1 in a murine model of VOD produced by long-term nitric oxide synthase inhibition using L-NAME. After 6 weeks, wild-type (WT) mice developed extensive fibrinoid hepatic venous thrombi and biochemical evidence of hepatic injury and dysfunction. In contrast, PAI-1-deficient mice were largely protected from the development of hepatic vein thrombosis. Furthermore, WT mice that received tiplaxtinin, an antagonist of PAI-1, were effectively protected from L-NAME-induced thrombosis. Taken together, these data indicate that NO and PAI-1 play pivotal and antagonistic roles in hepatic vein thrombosis and that PAI-1 is a potential target in the prevention and treatment of VOD in humans.


Assuntos
Síndrome de Budd-Chiari/etiologia , Inibidor 1 de Ativador de Plasminogênio/fisiologia , Animais , Síndrome de Budd-Chiari/induzido quimicamente , Síndrome de Budd-Chiari/prevenção & controle , Modelos Animais de Doenças , Hepatopatia Veno-Oclusiva/induzido quimicamente , Hepatopatia Veno-Oclusiva/etiologia , Ácidos Indolacéticos , Indóis/farmacologia , Camundongos , Camundongos Knockout , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Inibidor 1 de Ativador de Plasminogênio/genética
7.
J Biol Chem ; 279(18): 18127-36, 2004 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-14963043

RESUMO

Plasminogen activator inhibitor-1 (PAI-1) is the major inhibitor of plasminogen activation and likely plays important roles in coronary thrombosis and arteriosclerosis. Tumor necrosis factor-alpha (TNFalpha) is one of many recognized physiological regulators of PAI-1 expression and may contribute to elevated plasma PAI-1 levels in sepsis and obesity. Although TNFalpha is a potent inducer of PAI-1 expression in vitro and in vivo, the precise location of the TNFalpha response site in the PAI-1 promoter has yet to be determined. Transient transfection studies using luciferase reporter constructs containing PAI-1 promoter sequence up to 6.4 kb failed to detect a response to TNFalpha. Moreover, TNFalpha failed to induce expression of enhanced green fluorescent protein under the control of a 2.9-kb human PAI-1 promoter in transgenic mice, although endogenous murine PAI-1 was strongly induced. These data suggested that the TNFalpha response element in the PAI-1 gene is remote from the proximal promoter region. In this study, seven candidate regulatory regions were identified using cross-species sequence homology analysis as well as DNase I-hypersensitive site analysis. We identified a 5' distal TNFalpha-responsive enhancer of the PAI-1 gene located 15 kb upstream of the transcription start site containing a conserved NFkappaB-binding site that mediates the response to TNFalpha. This newly recognized site is fully capable of binding NFkappaB subunits p50 and p65, whereas overexpression of the NFkappaB inhibitor IkappaB prevents TNFalpha-induced activation of this enhancer element.


Assuntos
NF-kappa B/genética , Inibidor 1 de Ativador de Plasminogênio/genética , Ativação Transcricional , Fator de Necrose Tumoral alfa/fisiologia , Animais , Aorta , Sequência de Bases , Sítios de Ligação , Bovinos , Endotélio Vascular/citologia , Humanos , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Inibidor 1 de Ativador de Plasminogênio/biossíntese , Regiões Promotoras Genéticas , Elementos de Resposta , Homologia de Sequência do Ácido Nucleico , Veias Umbilicais
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