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1.
Mar Pollut Bull ; 200: 116098, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38310721

RESUMO

Climate change is viewed as the primary threat to coral reefs, with local pressures exacerbating coral cover decline. The consensus is that improving water quality may increase resilience, but disentangling water quality and temperature impacts is difficult. We used distance-based linear models and random forests to analyze spatiotemporal variation in benthic community structure and interannual changes in the coral assemblage, in relation to specific environmental metrics in Southeast Florida. Temperature accounted for most of the variation, recruitment doubled and interannual increases in coral abundance tripled when mean annual temperature reached 27 °C, until maximum temperatures exceeded 31 °C. Benefits associated with warmer temperatures were negated by poor water quality, as nutrient enrichment was related to increased macroalgal cover, reduced coral recruitment and higher coral partial mortality. We suggest reducing local pressures will contribute to reduced macroalgae and enhance coral recovery, but that temperature is the predominant influence on coral assemblages.


Assuntos
Antozoários , Animais , Temperatura , Florida , Efeitos Antropogênicos , Recifes de Corais
2.
Proc Biol Sci ; 288(1961): 20211613, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34666521

RESUMO

The rapid loss of reef-building corals owing to ocean warming is driving the development of interventions such as coral propagation and restoration, selective breeding and assisted gene flow. Many of these interventions target naturally heat-tolerant individuals to boost climate resilience, but the challenges of quickly and reliably quantifying heat tolerance and identifying thermotolerant individuals have hampered implementation. Here, we used coral bleaching automated stress systems to perform rapid, standardized heat tolerance assays on 229 colonies of Acropora cervicornis across six coral nurseries spanning Florida's Coral Reef, USA. Analysis of heat stress dose-response curves for each colony revealed a broad range in thermal tolerance among individuals (approx. 2.5°C range in Fv/Fm ED50), with highly reproducible rankings across independent tests (r = 0.76). Most phenotypic variation occurred within nurseries rather than between them, pointing to a potentially dominant role of fixed genetic effects in setting thermal tolerance and widespread distribution of tolerant individuals throughout the population. The identification of tolerant individuals provides immediately actionable information to optimize nursery and restoration programmes for Florida's threatened staghorn corals. This work further provides a blueprint for future efforts to identify and source thermally tolerant corals for conservation interventions worldwide.


Assuntos
Antozoários , Termotolerância , Animais , Antozoários/fisiologia , Censos , Recifes de Corais , Florida
3.
Sci Rep ; 11(1): 14113, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34238939

RESUMO

Rare species population dynamics can elucidate the resilience of an ecosystem. On coral reefs, climate change and local anthropogenic stressors are threatening stony coral persistence, increasing the need to assess vulnerable species locally. Here, we monitored the threatened pillar coral, Dendrogyra cylindrus, population in southeast Florida, USA, in relation to consecutive heat stress events in 2014 and 2015. In the fall of each year, D. cylindrus colonies bleached following intense thermal stress and by June 2020 all monitored colonies died from a white-syndrome type disease. This resulted in the ecological extinction of D. cylindrus in the Southeast Florida Coral Reef Ecosystem Conservation Area (ECA). White-syndrome type disease was first seen in February 2014 on four colonies (19% prevalence) near the major international port, Port Everglades and disease prevalence peaked in fall 2015 (58%). Disease prevalence increased with maximum water temperature, while disease related mortality increased with mean water temperature. Our findings suggest that thermal stress exacerbated underlying stony coral disease, resulting in an outbreak contributing to the ecological extirpation of D. cylindrus in the ECA. We suggest that stony coral resilience is severely compromised by chronic environmental disturbance which hinders community recovery.


Assuntos
Antozoários/fisiologia , Espécies em Perigo de Extinção , Estresse Fisiológico , Temperatura , Animais , Florida , Geografia , Água
4.
Adv Mar Biol ; 87(1): 83-114, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33293021

RESUMO

Little to no recovery in Acropora cervicornis populations has been documented since the 1970s and 1980s widespread disease events, and disease and predation appear to remain significant drivers of mortality. However, to date, demographic studies of A. cervicornis lack data temporally or spatially sufficient to quantify factors limiting recovery. Acropora cervicornis populations in three regions [Broward County (BWD), Middle Keys (MDK), and Dry Tortugas (DRTO)] of the Florida Reef Tract were surveyed up to three times per year from 2011 to 2015. Temporal and spatial differences were evaluated for colony size, live tissue volume, and prevalence and impact of disease and predation. Significantly larger colonies were reported in BWD, and at relatively deeper or more sheltered sites. At least 43% of colonies in each region were of reproductively capable size. Mean relative change in colony size between surveys (3-5 months) ranged from -20% to 19%. Disease and predation were consistently present in all regions, but levels varied significantly across space and time. Disease prevalence was the most variable condition (ranging from 0% to 28% per survey), increasing after periods of elevated temperatures and environmental disturbances, and caused significantly more partial mortality than fireworm (Hermodice carunculata) or snail (Coralliophila spp.) predation. Recovery potential and long-term persistence of this species may be limited due to the persistent presence of disease and predation, and reproductive limitations. However, there is still potential at sites of greater depth and/or more protection hosted larger and healthier colonies creating potential refugia for this species.


Assuntos
Antozoários , Recifes de Corais , Animais , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Florida
5.
EPJ Web Conf ; 2192019.
Artigo em Inglês | MEDLINE | ID: mdl-36452450

RESUMO

A precise value of the neutron lifetime is important in several areas of physics, including determinations of the quark-mixing matrix element │V ud│, related tests of the Standard Model, and predictions of light element abundances in Big Bang Nucleosynthesis models. We report the progress on a new measurement of the neutron lifetime utilizing the cold neutron beam technique. Several experimental improvements in both neutron and proton counting that have been developed over the last decade are presented. This new effort should yield a final uncertainty on the lifetime of 1 s with an improved understanding of the systematic effects.

6.
PeerJ ; 6: e4433, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29507829

RESUMO

Acropora cervicornis is the most widely used coral species for reef restoration in the greater Caribbean. However, outplanting methodologies (e.g., colony density, size, host genotype, and attachment technique) vary greatly, and to date have not been evaluated for optimality across multiple sites. Two experiments were completed during this study, the first evaluated the effects of attachment technique, colony size, and genotype by outplanting 405 A. cervicornis colonies, from ten genotypes, four size classes, and three attachment techniques (epoxy, nail and cable tie, or puck) across three sites. Colony survival, health condition, tissue productivity, and growth were assessed across one year for this experiment. The second experiment assessed the effect of colony density by outplanting colonies in plots of one, four, or 25 corals per 4 m2 across four separate sites. Plot survival and condition were evaluated across two years for this experiment in order to better capture the effect of increasing cover. Colonies attached with a nail and cable tie resulted in the highest survival regardless of colony size. Small corals had the lowest survival, but the greatest productivity. The majority of colony loss was attributed to missing colonies and was highest for pucks and small epoxied colonies. Disease and predation were observed at all sites, but did not affect all genotypes, however due to the overall low prevalence of either condition there were no significant differences found in any comparison. Low density plots had significantly higher survival and significantly lower prevalence of disease, predation, and missing colonies than high density plots. These results indicate that to increase initial outplant success, colonies of many genotypes should be outplanted to multiple sites using a nail and cable tie, in low densities, and with colonies over 15 cm total linear extension.

7.
Glob Chang Biol ; 24(2): 773-785, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29076634

RESUMO

Changes in coral-sponge interactions can alter reef accretion/erosion balance and are important to predict trends on current algal-dominated Caribbean reefs. Although sponge abundance is increasing on some coral reefs, we lack information on how shifts from corals to bioeroding sponges occur, and how environmental factors such as anomalous seawater temperatures and consequent coral bleaching and mortality influence these shifts. A state transition model (Markov chain) was developed to evaluate the response of coral-excavating sponges (Cliona delitrix Pang 1973) after coral bleaching events. To understand possible outcomes of the sponge-coral interaction and build the descriptive model, sponge-corals were monitored in San Andres Island, Colombia (2004-2011) and Fort Lauderdale, Florida (2012-2013). To run the model and determine possible shifts from corals to excavating sponges, 217 coral colonies were monitored over 10 years (2000-2010) in Fort Lauderdale, Florida, and validated with data from 2011 to 2015. To compare and test its scalability, the model was also run with 271 coral colonies monitored in St. Croix, US Virgin Islands over 7 years (2004-2011), and validated with data from 2012 to 2015. Projections and sensitivity analyses confirmed coral recruitment to be key for coral persistence. Excavating sponge abundance increased in both Fort Lauderdale and St. Croix reefs after a regional mass bleaching event in 2005. The increase was more drastic in St. Croix than in Fort Lauderdale, where 25% of the healthy corals that deteriorated were overtaken by excavating sponges. Projections over 100 years suggested successive events of coral bleaching could shift algae-coral dominated reefs into algae-sponge dominated. The success of excavating sponges depended on the intensity of coral bleaching and consequent coral mortality. Thus, the proportion of C. delitrix excavating sponges is a sensitive indicator for the intensity and frequency of recent disturbance on Caribbean coral reefs.


Assuntos
Antozoários/fisiologia , Recifes de Corais , Poríferos/fisiologia , Animais , Colômbia , Florida , Ilhas , Cadeias de Markov , Modelos Biológicos , Água do Mar , Temperatura , Fatores de Tempo
8.
PeerJ ; 4: e2473, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27703844

RESUMO

Dense Acropora cervicornis aggregations, or patches, have been documented within nearshore habitats in Southeast Florida (SE FL) despite close proximity to numerous anthropogenic stressors and subjection to frequent natural disturbance events. Limited information has been published concerning the distribution and abundance of A. cervicornis outside of these known dense patches. The first goal of this study was to conduct a spatially extensive and inclusive survey (9.78 km2) to determine whether A. cervicornis distribution in the nearshore habitat of SE FL was spatially uniform or clustered. The second goal was to investigate potential relationships between broad-scale seafloor topography and A. cervicornis abundance using high resolution bathymetric data. Acropora cervicornis was distributed throughout the study area, and the Getis-Ord Gi* statistic and Anselin Local Moran's I spatial cluster analysis showed significant clustering along topographic features termed ridge crests. Significant clustering was further supported by the inverse distance weighted surface model. Ordinal logistic regression indicated 1) as distance from a ridge increases, odds of reduced A. cervicornis abundance increases; 2) as topographic elevation increases, odds of increased abundance increases; and 3) as mean depth increases, odds of increased abundance increases. This study provides detailed information on A. cervicornis distribution and abundance at a regional scale and supports modeling its distributions in similar habitats elsewhere throughout the western Atlantic and Caribbean. Acropora cervicornis is frequently observed and in areas an abundant species within the nearshore habitat along the SE FL portion of the Florida Reef Tract (FRT). This study provides a better understanding of local habitat associations thus facilitating appropriate management of the nearshore environment and species conservation. The portion of the FRT between Hillsboro and Port Everglades inlets should be considered for increased management and protection to reduce local stressors.

9.
Rev. biol. trop ; 62(supl.3): 299-308, Jul.-Sep. 2014. ilus, graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-757333

RESUMO

Recent evidence shows that Acropora palmata within the Veracruz Reef System, located in the southwestern Gulf of Mexico, may be recovering after the die off from the flooding of the Jamapa River and a dramatic cold water event in the 1970s. Since this decline, few surveys have documented the status of A. palmata. The 28 named reefs in the system are divided into 13 northern and 15 southern groups by the River. Between 2007 and 2013, we surveyed 24 reefs to assess the benthic communities. Seven of the 11 reefs surveyed in the northern group and all in the southern group had A. palmata. Colonies were typically found on the windward side of the reefs in shallow waters along the reef edges or crest. We also recorded colony diameter and condition along belt transects at two reefs in the north (Anegada de Adentro and Verde) and two in the south (Periferico and Sargazo), between 2011 and 2013. In addition, eight permanent transects were surveyed at Rizo (south). A total of 1 804 colonies were assessed; densities ranged from 0.02 to 0.28 colonies/m² (mean (±SD), colony diameter of 58 ± 73cm, and 89 ± 18% live tissue per colony). Total prevalence of predation by damselfish was 5%, by snails 2%, and <1% by fireworms, disease prevalence was <3%. Size frequency distributions indicated that all of the sites had a moderate to high spawning potential, 15-68% of the colonies at each site were mature, measuring over 1 600cm². The presence of these healthy and potentially reproductive colonies is important for species recovery, particularly because much of the greater Caribbean still shows little to no signs of recovery. Conservation and management efforts of these reefs are vital.


Evidencia reciente indica que las poblaciones de Acropora palmata del sistema arrecifal de Vera Cruz, ubicado al suroeste del Golfo de México, podría estarse recuperando después de las inundaciones del río Jamapa e intrusiones de agua fría que afectaron la región en los años setenta. Desde la disminución, pocos estudios han documentado el estado A. palmata. Consiste de 28 arrecifes divididos 13 al norte y 15 al sur del río. Entre el 2007 y 2013 se muestrearon 24 arrecifes para caracterizar las comunidades bentónicas. Siete de los 11 arrecifes del norte y en todos los arrecifes del sur tenían A. palmata. Las colonias se encontraron por lo general en el barlovento de los corales en agua sómeras a lo largo del borde del arrecife. También registramos los diámetros de las colonias y condición a lo largo de transectos tipo conturón en dos arrecifes al norte (Anegada de Adentro y Verde) y dos en el sur (Periférico y Sargazo), entre el 2011 y 2013. Además, ocho transectos se evaluaron en Rizo (al sur). Evaluamos un total de 1 804 colonias; las densidades variaron entre 0.02 a 0.28 colonias/m² (promedio (±DE) del diámetro de colonia 58± 3cm y 89±18% de tejido vivo por colonia). La depredación fue 5% por peces damisela, 2% por caracoles y <1% por gusanos, prevalencia de enfermedades <3%. La distribución de tamaños indicó que las poblaciones tienen un potencial moderado a alto de desove, 15-68 de las colonias eran maduras, y medían más de 1 600cm².La presencia de estas colonias saludables y potencialmente reproductivas son importantes para la recuperación de especies, particularmente porque el Caribe muestra muy pocas o ninguna señale de recuperación. Esfuerzos en conservación y manejo en estos arrecifes es vital.

10.
Front Genet ; 5: 436, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25566321

RESUMO

Genetic factors influence fetal alcohol spectrum disorders (FASDs) in both humans and animals. Experiments using inbred and selectively bred mouse stocks that controlled for (1) ethanol dose, (2) maternal and fetal blood ethanol levels, and (3) fetal developmental exposure stage, show genotype can affect teratogenic outcome. Other experiments distinguish the teratogenic effects mediated by maternal genotype from those mediated by fetal genotype. One technique to distinguish maternal versus fetal genotype effect is to utilize embryo transfers. This study is the first to examine ethanol teratogenesis - fetal weight deficits and mortality, and digit, kidney, and vertebral malformations - in C57BL/6J (B6) and DBA/2J (D2) fetuses that were transferred as blastocysts into B6 and D2 dams. We hypothesized that, following maternal alcohol exposure, B6 and D2 fetuses gestating within B6 mothers, as compared to D2 mothers, will exhibit a higher frequency of malformations. On day 9 of pregnancy, females were intubated (IG) with either 5.8 g/kg ethanol (E) or maltose-dextrin (MD). Other females were mated within strain and treated with either ethanol or maltose, or were not exposed to either treatment. Implantation rates were affected by genotype. Results show more B6 embryos implanted into D2 females than B6 females (p < 0.05; 47% vs. 23%, respectively). There was no difference in the percentage of D2 embryos implanting into B6 and D2 females (14 and 16%, respectfully). Litter mortality averaged 24% across all experimental groups. Overall, in utero ethanol exposure reduced mean litter weight compared to maltose treatment (E = 1.01 g; MD = 1.19 g; p < 0.05); but maltose exposed litters with transferred embryos weighed more than similarly treated natural litters (1.30 g vs. 1.11 g; p < 0.05). Approximately 50% of all ethanol exposed B6 fetuses exhibited some malformation (digit, vertebral, and/or kidney) regardless of whether they were transferred into a B6 or D2 female, or were naturally conceived. This suggests the D2 maternal uterine environment did not offer any protection against ethanol teratogenesis for B6 fetuses. One of the questions remaining is the how the B6 uterine environment affects D2 teratogenesis. No definitive conclusions can be drawn because too few viable D2 litters were produced.

11.
PLoS One ; 8(11): e80439, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24282542

RESUMO

Climate change has recently been implicated in poleward shifts of many tropical species including corals; thus attention focused on higher-latitude coral communities is warranted to investigate possible range expansions and ecosystem shifts due to global warming. As the northern extension of the Florida Reef Tract (FRT), the third-largest barrier reef ecosystem in the world, southeast Florida (25-27° N latitude) is a prime region to study such effects. Most of the shallow-water FRT benthic habitats have been mapped, however minimal data and limited knowledge exist about the coral reef communities of its northernmost reaches off Martin County. First benthic habitat mapping was conducted using newly acquired high resolution LIDAR bathymetry and aerial photography where possible to map the spatial extent of coral reef habitats. Quantitative data were collected to characterize benthic cover and stony coral demographics and a comprehensive accuracy assessment was performed. The data were then analyzed in a habitat biogeography context to determine if a new coral reef ecosystem region designation was warranted. Of the 374 km(2) seafloor mapped, 95.2% was Sand, 4.1% was Coral Reef and Colonized Pavement, and 0.7% was Other Delineations. Map accuracy assessment yielded an overall accuracy of 94.9% once adjusted for known map marginal proportions. Cluster analysis of cross-shelf habitat type and widths indicated that the benthic habitats were different than those further south and warranted designation of a new coral reef ecosystem region. Unlike the FRT further south, coral communities were dominated by cold-water tolerant species and LIDAR morphology indicated no evidence of historic reef growth during warmer climates. Present-day hydrographic conditions may be inhibiting poleward expansion of coral communities along Florida. This study provides new information on the benthic community composition of the northern FRT, serving as a baseline for future community shift and range expansion investigations.


Assuntos
Antozoários/fisiologia , Recifes de Corais , Animais , Mudança Climática , Análise por Conglomerados , Florida
12.
Alcohol Clin Exp Res ; 36(8): 1340-54, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22413943

RESUMO

BACKGROUND: Individual differences in susceptibility to the detrimental effects of prenatal ethanol (EtOH) exposure have been demonstrated. Many factors, including genetics, play a role in susceptibility and resistance. We have previously shown that C57BL/6J (B6) mice display a number of morphological malformations following an acute dose of EtOH in utero, while DBA/2J (D2) mice are relatively resistant. Here, we present the results of quantitative trait locus (QTL) mapping for EtOH teratogenesis in recombinant inbred strains derived from a cross between B6 and D2 (BXD RIs). METHODS: Pregnant dams were intubated with either maltose-dextrin or 5.8 g/kg EtOH on day 9 of gestation (GD9). On GD 18, dams were sacrificed and fetuses and placentae were removed. Placentae and fetuses were weighed; fetuses were sexed and examined for gross morphological malformations. Fetuses were then either placed in Bouin's fixative for subsequent soft-tissue analyses or eviscerated and placed in EtOH for subsequent skeletal examinations. QTL mapping for maternal weight gain (MWG), prenatal mortality, fetal weight (FW) at c-section, placental weight (PW), and several morphological malformations was performed using WebQTL. RESULTS: Heritability for our traits ranged from 0.06 for PW to 0.39 for MWG. We found suggestive QTLs mediating all phenotypes and significant QTLs for FW and digit and rib malformations. While most QTL regions are large, several intriguing candidate genes emerged based on polymorphisms between B6 and D2 and gene function. CONCLUSIONS: In this first mapping study for EtOH teratogenesis, several QTLs were identified. Future studies will further characterize these regions. Identification of genes and epigenetic modifications mediating susceptibility to the teratogenic effects of alcohol in mice will provide targets to examine in human populations.


Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Etanol/toxicidade , Locos de Características Quantitativas/genética , Teratogênicos , Animais , Peso Corporal/efeitos dos fármacos , Mapeamento Cromossômico , Feminino , Feto/patologia , Deformidades do Pé/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Tamanho do Órgão/efeitos dos fármacos , Placenta/efeitos dos fármacos , Gravidez , Locos de Características Quantitativas/fisiologia , Aumento de Peso/efeitos dos fármacos
13.
Rev. biol. trop ; 60(supl.1): 99-108, Mar. 2012. ilus, graf, tab
Artigo em Inglês | LILACS, SaludCR | ID: lil-657857

RESUMO

Over the last two decades, more than 10 major vessel groundings have occurred on coral reefs offshore southeast Florida. Lack of any published information on coral settlement, post-settlement survival, and juvenile coral growth in the southeast Florida region inhibits efforts to determine if coral populations will be able to effectively re-establish themselves. The goal of this study was to examine these processes to obtain background data needed to determine the potential for natural recovery. Over a three year period annual coral recruitment, juvenile growth, and mortality rates were measured in 20 permanent quadrats at each of two ship grounding and two control sites. The density of new recruits was generally low, ranging from 0.2±0.1 (SE) to 7.1±1.0 recruits m-2. Although the density of coral recruits was generally higher at the grounding sites, mortality rates were high at all sites during the study period. Growth rates of individual colonies were highly variable, and many of the colonies shrank in size due to partial mortality. Results indicate that corals are able to recruit to the damaged reefs but that slow growth rates and high mortality rates may keep these areas in a perpetual cycle of settlement and mortality with little or extremely slow growth to larger size classes, thus inhibiting recovery.


En las dos últimas décadas, más de10 grandes encallamientos de embarcaciones se han producido en los arrecifes de coral mar afuera en el sureste de Florida. La falta de información publicada sobre el asentamiento de corales y sobrevivencia post-asentamiento y de los corales juveniles que crecen en la región, limita los esfuerzos para determinar si las poblaciones de coral serán capaces de restablecerse por ellas mismas. El objetivo de este estudio fue examinar estos procesos para obtener la información necesaria para determinar el potencial de recuperación natural. Se midió el reclutamiento anual de coral joven, el crecimiento y las tasas de mortalidad por un período de tres años, mediante 20 cuadrantes permanentes en cada uno de los dos encallamientos de barcos y dos sitios de control. La densidad de nuevos reclutamientos fue generalmente baja, de 0.2±0.1 a 7.1±1.0 reclutamientos m-2. Aunque la densidad del reclutamiento fue generalmente más alta en los sitios de encallamiento también hubo mayor mortalidad de corales juveniles en esos sitios durante el período de estudio. Las tasas de crecimiento de las colonias individuales fueron altamente variables, y muchas de las colonias se redujeron en tallas debido a mortalidad parcial. Los resultados indican que los corales presentan una disposición a reclutarse en arrecifes dañados, pero las lentas tasas de crecimiento y la alta mortalidad pueden mantener esas áreas en un perpetuo ciclo de asentamiento y mortalidad con poco o extremadamente lento crecimiento hacia las clases de tallas largas, por lo tanto inhibiendo la recuperación.


Assuntos
Florida , Antozoários/anatomia & histologia , Recifes de Corais , Navios , Estados Unidos
14.
PLoS One ; 6(8): e23047, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21853066

RESUMO

BACKGROUND: Coral reefs are facing increasing pressure from natural and anthropogenic stressors that have already caused significant worldwide declines. In January 2010, coral reefs of Florida, United States, were impacted by an extreme cold-water anomaly that exposed corals to temperatures well below their reported thresholds (16°C), causing rapid coral mortality unprecedented in spatial extent and severity. METHODOLOGY/PRINCIPAL FINDINGS: Reef surveys were conducted from Martin County to the Lower Florida Keys within weeks of the anomaly. The impacts recorded were catastrophic and exceeded those of any previous disturbances in the region. Coral mortality patterns were directly correlated to in-situ and satellite-derived cold-temperature metrics. These impacts rival, in spatial extent and intensity, the impacts of the well-publicized warm-water bleaching events around the globe. The mean percent coral mortality recorded for all species and subregions was 11.5% in the 2010 winter, compared to 0.5% recorded in the previous five summers, including years like 2005 where warm-water bleaching was prevalent. Highest mean mortality (15%-39%) was documented for inshore habitats where temperatures were <11°C for prolonged periods. Increases in mortality from previous years were significant for 21 of 25 coral species, and were 1-2 orders of magnitude higher for most species. CONCLUSIONS/SIGNIFICANCE: The cold-water anomaly of January 2010 caused the worst coral mortality on record for the Florida Reef Tract, highlighting the potential catastrophic impacts that unusual but extreme climatic events can have on the persistence of coral reefs. Moreover, habitats and species most severely affected were those found in high-coral cover, inshore, shallow reef habitats previously considered the "oases" of the region, having escaped declining patterns observed for more offshore habitats. Thus, the 2010 cold-water anomaly not only caused widespread coral mortality but also reversed prior resistance and resilience patterns that will take decades to recover.


Assuntos
Antozoários/fisiologia , Temperatura Baixa , Recifes de Corais , Água do Mar , Animais , Florida , Geografia , Oceanos e Mares , Análise de Sobrevida , Taxa de Sobrevida
15.
Alcohol ; 45(5): 441-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21641750

RESUMO

Genetic factors influence adverse pregnancy outcome in both humans and animal models. Animal research reveals that both the maternal and fetal genetic profiles are important for determining the risk of physical birth defects and prenatal mortality. Using a reciprocal-cross breeding design, we investigated whether the mother's genes may be more important than fetal genes in determining risk for ethanol teratogenesis. Examination of possible synergistic genetic effects on ethanol teratogenesis was made possible by using two mouse strains known to be susceptible to specific malformations. Inbred A/J (A) and C57BL/6J (B6) mice were mated to produce four fetal genotype groups: the true-bred AcA and B6cB6 genotypes and the genetically identical AcB6 and B6cA genotypes (the F(1) genotype). Dams were administered either 5.8 g/kg ethanol or an isocaloric amount of maltose-dextrin on day 9 of pregnancy. Fetuses were removed by laparotomy on gestation day 18, weighed, and assessed for digit, vertebral, and kidney malformations. Digit malformations in the genetically identical F(1) ethanol-exposed litters showed a pattern consistent with a maternal genetic effect (AcB6 [2%] and B6cA [30%]). In contrast, vertebral malformations were similar in all ethanol-exposed litters (AcA [26%], AcB6 [18%], B6cA [22%], and B6cB6 [33%]). The percentage of malformations did not differ between male and female fetuses, indicating sex-linked factors are not responsible for the maternal effect. Ethanol exposure decreased litter weights but did not affect litter mortality compared with maltose-exposed controls. This study supports the idea that genes influence malformation risk following in utero alcohol exposure. Specifically, maternal genes influence risk more than fetal genes for some teratogenic outcomes. No evidence supported synergistic genetic effects on ethanol teratogenesis. This research supports the conclusion that uterine environment contributes to determining risk of Fetal Alcohol Spectrum Disorder.


Assuntos
Anormalidades Induzidas por Medicamentos/genética , Etanol/toxicidade , Exposição Materna , Teratogênicos , Animais , Cruzamentos Genéticos , Feminino , Transtornos do Espectro Alcoólico Fetal/genética , Mortalidade Fetal , Membro Anterior/anormalidades , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Gravidez , Coluna Vertebral/anormalidades
16.
PLoS One ; 5(11): e13969, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21125021

RESUMO

BACKGROUND: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.


Assuntos
Antozoários/crescimento & desenvolvimento , Recifes de Corais , Estresse Fisiológico/fisiologia , Temperatura , Animais , Região do Caribe , Clima , Ecossistema , Monitoramento Ambiental , Geografia , Oceanos e Mares , Análise de Sobrevida , Movimentos da Água
17.
Toxicol Sci ; 116(2): 632-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20457659

RESUMO

Valproic acid (VPA) is used worldwide to treat epilepsy, migraine headaches, and bipolar disorder. However, VPA is teratogenic and in utero exposure can lead to congenital malformations. Using inbred C57BL/6J (B6) and DBA/2J (D2) mice, we asked whether genetic variation could play a role in susceptibility to VPA teratogenesis. Whereas B6 fetuses were more susceptible than D2 fetuses to digit and vertebral malformations, D2 fetuses were more susceptible to rib malformations. In a reciprocal cross between B6 and D2, genetically identical F1 mice carried in a B6 mother had a greater percentage of vertebral malformations following prenatal VPA exposure than F1 mice carried in a D2 mother. This reciprocal F1 difference is known as a maternal effect and shows that maternal genotype/uterine environment is an important mediator of VPA teratogenecity. VPA is a histone deacetylase inhibitor, and it is possible that the differential teratogenesis in B6 and D2 is because of strain differences in histone acetylation. We observed strain differences in acetylation of histones H3 and H4 in both embryo and placenta following in utero VPA exposure, but additional studies are needed to determine the significance of these changes in mediating teratogenesis. Our results provide additional support that genetic factors, both maternal and fetal, play a role in VPA teratogenesis. Lines of mice derived from B6 and D2 will be a useful model for elucidating the genetic architecture underlying susceptibility to VPA teratogenesis.


Assuntos
Anormalidades Induzidas por Medicamentos/etiologia , Anticonvulsivantes/toxicidade , Ácido Valproico/toxicidade , Animais , Western Blotting , Relação Dose-Resposta a Droga , Feminino , Genótipo , Inibidores de Histona Desacetilases/toxicidade , Histona Desacetilases/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Especificidade da Espécie
18.
Alcohol Clin Exp Res ; 33(7): 1238-45, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19389189

RESUMO

BACKGROUND: Previous studies have demonstrated individual differences in susceptibility to the detrimental effects of prenatal ethanol exposure. Many factors, including genetic differences, have been shown to play a role in susceptibility and resistance, but few studies have investigated the range of genetic variation in rodent models. METHODS: We examined ethanol teratogenesis in 5 inbred strains of mice: C57BL/6J (B6), Inbred Short-Sleep, C3H/Ibg, A/Ibg, and 129S6/SvEvTac (129). Pregnant dams were intubated with either 5.8 g/kg ethanol (E) or an isocaloric amount of maltose-dextrin (MD) on day 9 of pregnancy. Dams were sacrificed on day 18 and fetuses were weighed, sexed, and examined for gross morphological malformations. Every other fetus within a litter was then either placed in Bouin's fixative for subsequent soft-tissue analyses or eviscerated and placed in ethanol for subsequent skeletal analyses. RESULTS: B6 mice exposed to ethanol in utero had fetal weight deficits and digit, kidney, brain ventricle, and vertebral malformations. In contrast, 129 mice showed no teratogenesis. The remaining strains showed varying degrees of teratogenesis. CONCLUSIONS: Differences among inbred strains demonstrate genetic variation in the teratogenic effects of ethanol. Identifying susceptible and resistant strains allows future studies to elucidate the genetic architecture underlying prenatal alcohol phenotypes.


Assuntos
Anormalidades Induzidas por Medicamentos/genética , Anormalidades Induzidas por Medicamentos/patologia , Etanol/toxicidade , Animais , Feminino , Masculino , Exposição Materna , Camundongos , Camundongos Endogâmicos A , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Efeitos Tardios da Exposição Pré-Natal/patologia , Especificidade da Espécie , Teratogênicos/toxicidade
19.
Alcohol Alcohol ; 44(1): 25-33, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18854366

RESUMO

AIMS: Prenatal exposure to alcohol can have adverse effects on the developing fetus. Two of the hallmarks of children exposed to alcohol prenatally are attention deficits and hyperactivity. While hyperactivity has been observed in rats following prenatal ethanol exposure, few studies have examined these effects in mice. The present study investigated the effects of prenatal ethanol exposure on activity in mice from three inbred strains: C57BL/6 (B6), Inbred Long Sleep (ILS) and Inbred Short Sleep (ISS). METHODS: On Days 7 through 18 of gestation, mice were intragastrically intubated twice daily with either 3.0 g/kg ethanol (E) or an isocaloric amount of maltose-dextrin (MD); non-intubated control (NIC) litters were also generated. Offspring activity was monitored at 30, 60, 90 and 150 days of age. RESULTS: While results showed no effects of prenatal ethanol exposure on any measures of activity, we did observe differences in baseline activity among the strains. ISS mice were more active than B6 and ILS for all activity measures except stereotypy; B6 mice had higher measures of stereotypy than ILS and ISS. Younger mice were more active than older mice. The only sex effects were on measures of stereotypy, where males had higher scores. CONCLUSIONS: Mice are an excellent organism to study genetic influences on many phenotypes. However, our study and others have shown few effects of prenatal ethanol exposure on behavior in mice. It appears as if the prenatal period in mice, corresponding to organogenesis, is not a sensitive period for producing behavioral deficits following ethanol exposure. It is likely that the first 2 weeks postnatally, corresponding to the brain growth spurt, are more sensitive for producing behavioral effects.


Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Etanol/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Animais , Peso ao Nascer/efeitos dos fármacos , Depressores do Sistema Nervoso Central/sangue , Etanol/sangue , Feminino , Reabsorção do Feto/induzido quimicamente , Reabsorção do Feto/patologia , Hipercinese/induzido quimicamente , Hipercinese/psicologia , Tamanho da Ninhada de Vivíparos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Gravidez , Comportamento Estereotipado/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacos
20.
J Res Natl Inst Stand Technol ; 114(3): 195-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-27504221

RESUMO

Performance standards for detector systems often include requirements for probability of detection and probability of false alarm at a specified level of statistical confidence. This paper reviews the accepted definitions of confidence level and of critical value. It describes the testing requirements for establishing either of these probabilities at a desired confidence level. These requirements are computable in terms of functions that are readily available in statistical software packages and general spreadsheet applications. The statistical interpretations of the critical values are discussed. A table is included for illustration, and a plot is presented showing the minimum required numbers of pass-fail tests. The results given here are applicable to one-sided testing of any system with performance characteristics conforming to a binomial distribution.

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