Asociaciones de larvas de peces en relación a cambios ambientales en las Bahías Chamela, Jalisco y Santiago-Manzanillo, Colima (2001-2002)

Spatial and temporal structure of fish larvae associations and their relationship to the environmental variability were studied at Bahía Chamela, Jalisco, and Santiago-Manzanillo complex, Colima, during 2001-2002. Two spatial aggregations were found, related to the coastal physiography and to the adult habitat. The first was observed at Bahía Chamela, which integrated a combination of species belonging to coastal, demersal and inshore habitats (Bregmaceros bathymaster, Bairdiella sp., Cynoscion sp., Engraulis mordax, and Labrisomidae type 1) and the other in Santiago-Manzanillo composed by species from lagoon and inshore areas (Eucinostomus sp., Abudefduf troschelii, Haemulidae type 2 and 3, and Enneanectes sexmaculatus). Temporal organization was influenced by the environmental shift between two periods (warm and temperate) defined by the regional environmental variability. The warm period was characterized by tropical species (Harengula thrissina, Eucinostomus sp., Auxis sp., and Haemulidae type 3), related to high temperature and rainfall, while temperate period was dominated by species with a tropical-subtropical affinity (B. bathymaster, Bairdiella sp., Cynoscion sp., and E. mordax) and related to lower temperature and elevated nutrients, chlorophyll a and plankton concentrations.Se analizó la influencia de los factores ambientales sobre las asociaciones espacio-temporales de larvas de peces frente a Bahía Chamela, Jalisco y el conjunto de bahías Santiago-Manzanillo, Colima, durante un ciclo anual (2001-2002). Se identificaron dos agrupaciones relacionadas con la fisiografía de la costa y el hábitat de los adultos, una frente a Bahía Chamela integrada por una mezcla de especies de hábitats costero, demersal e intermareal-submareal (Bregmaceros bathymaster, Bairdiella sp., Cynoscion sp., Engraulis mordax y Labrisomidae tipo 1) y otra en Santiago-Manzanillo compuesta por especies de origen lagunar e intermareal-submareal (Eucinostomus sp., Abudefduf troschelii, Haemulidae tipos 2 y 3, así como Enneanectes sexmaculatus). La organización temporal estuvo influenciada por la alternancia entre dos periodos (cálido y templado) definidos por la variabilidad ambiental regional. El periodo cálido estuvo caracterizado por especies principalmente tropicales (Harengula thrissina, Eucinostomus sp., Auxis sp. y Haemulidae tipo 3), relacionadas con una mayor temperatura y precipitación pluvial, en cambio durante el periodo templado dominaron las especies de afinidad tropical-subtropical (B. bathymaster, Bairdiella sp., Cynoscion sp. y E. mordax), relacionadas con una menor temperatura e incrementos en las concentraciones de nutrimentos, clorofila-a y zooplancton

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Role of oceanography in shaping the genetic structure in the North Pacific hake <i>Merluccius productus</i>

<div><p>Determining the relative influence of biotic and abiotic factors on genetic connectivity among populations remains a major challenge in evolutionary biology and in the management and conservation of species. North Pacific hake (<i>Merluccius productus</i>) inhabits upwelling regions in the California Current ecosystem from the Gulf of California to the Gulf of Alaska. In this study, we examined mitochondrial DNA (mtDNA) and microsatellite variation to estimate levels of genetic differentiation of <i>M</i>. <i>productus</i> in relation to the role of oceanographic features as potential barriers to gene flow. Samples were obtained from nine sites spanning a large part of the geographic range of the species, from Puget Sound, Washington to Costa Rica. The microsatellite results revealed three genetically discrete populations: one spanning the eastern Pacific coast, and two apparently resident populations circumscribed to the Puget Sound and the northern Gulf of California (F_ST = 0.032, p = 0.036). Cytochrome b sequence data indicated that isolation between the Puget Sound and northern Gulf of California populations from the coastal Pacific were recent phenomena (18.5 kyr for Puget Sound and 40 kyr for the northern Gulf of California). Oceanographic data obtained from the Gulf of California support the hypothesis that permanent fronts within the region, and strong gradients at the entrance to the Gulf of California act as barriers to gene flow. A seascape genetics approach found significant genetic–environment associations, where the daytime sea surface temperature and chlorophyll concentrations were the best predictive variables for the observed genetic differentiation. Considering the potential causes of genetic isolation among the three populations, e.g. spawning areas in different latitudes associated with upwelling processes, oceanographic barriers, asymmetric migration and specialized diet, oceanographic barriers appear to be a likely mechanism restricting gene flow.</p></div

Relaxed Bayesian topology with the estimated divergence times based on CYTB sequences for populations of <i>Merluccius productus</i> obtained with BEAST [65].

<p>Numbers at nodes indicate divergence time in millions of years. Blue bars correspond to the 95% highest posterior density (HPD) intervals. For clarity, samples from the NGC, PC and PS were collapsed into triangles.</p

Hierarchical analysis of molecular variance (AMOVA) of genetic variation of <i>Merluccius productus</i> for mitochondrial DNA (mtDNA) and microsatellite loci (M).

<p>Hierarchical analysis of molecular variance (AMOVA) of genetic variation of <i>Merluccius productus</i> for mitochondrial DNA (mtDNA) and microsatellite loci (M).</p

Pairwise F_<i>ST</i> values (below diagonal) and ϕ_<i>ST</i> (above diagonal) for <i>Merluccius productus</i>.

<p>Location abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194646#pone.0194646.t001" target="_blank">Table 1</a>.</p

Role of oceanography in shaping the genetic structure in the North Pacific hake <i>Merluccius productus</i> - Fig 4

<p><b>Genetic barriers detected using pairwise population differentiation indices for <i>Merluccius productus</i>: a) mtDNA and b) microsatellite data.</b> Red lines indicate genetic barriers. Voronoï tessellation shown in blue and the corresponding Delaunay triangulation of samples in green. Numbers in parentheses indicate bootstrap percentages. Abbreviations are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194646#pone.0194646.t001" target="_blank">Table 1</a>.</p

Satellite and hydrographic data.

<p>Climatology of February of the Gulf of California (2002–2010) from the MODIS-Aqua satellites: sea surface temperature (SST) °C. Midriff archipelago region (MAR), northern Gulf of California (NGC), south of the Gulf of California (SGC), and entrance of Gulf of California (EGC).</p

Redundancy analysis (RDA) for the association of oceanographic variables obtained from Ocean Color Web, and the ancestry coefficients of the three populations.

<p>Puget Sound (PS), Pacific Coast (PC) and Northern Gulf of California (NGC) generated in STRUCTURE. Chlorophyll <i>a</i> concentration (CHL) and sea day time surface temperature (SSTd).</p