Environmental mediation of Atlantic cod on fish community composition: an application of multivariate regression tree analysis to exploited marine ecosystems

2010 ◽  
Vol 411 ◽  
pp. 189-201 ◽  
Author(s):  
JLW Ruppert ◽  
MJ Fortin ◽  
GA Rose ◽  
R Devillers
Keyword(s):  
Community Composition ◽  
Multivariate Regression ◽  
Fish Community ◽  
Atlantic Cod ◽  
Regression Tree ◽  
Tree Analysis ◽  
Multivariate Regression Tree ◽  
Environmental Mediation ◽  
Regression Tree Analysis ◽  
Fish Community Composition

scholarly journals Fibroblast Growth Factor 23 and α-Klotho Protein Are Associated with Adverse Clinical Outcomes in Non-Dialysis CKD Patients

2020 ◽  
Vol 45 (6) ◽  
pp. 900-915
Author(s):  
Eleni Manou ◽  
Elias Thodis ◽  
Georgios Arsos ◽  
Ploumis Pasadakis ◽  
Stylianos Panagoutsos ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Primary Endpoint ◽  
Multivariate Regression ◽  
Fibroblast Growth Factor 23 ◽  
Regression Tree ◽  
Fibroblast Growth ◽  
Multivariate Regression Tree ◽  
Regression Tree Analysis ◽  
Klotho Protein ◽  
Fgf 23

<b><i>Background:</i></b> Fibroblast growth factor 23 (FGF-23) and α-Klotho protein appear to have an important role in the pathogenesis of CKD-mineral and bone disorders. The aim of this study was to investigate the association of FGF-23 and α-Klotho levels with adverse clinical outcomes in patients with non-dialysis CKD. <b><i>Materials and Methods:</i></b> We conducted a prospective cohort study, enrolling participants with non-dialysis CKD from a single center in Greece. At enrollment, glomerular filtration rate (GFR) was measured (mGFR) and plasma levels of carboxyl terminal FGF-23 (cFGF-23) and soluble α-Klotho (sKlotho) were determined by enzyme-linked immunoassay. Participants were followed for up to 5 years or until the occurrence of the primary endpoint of initiation of renal replacement therapy or death. Multivariate regression tree analysis was used to identify informative baseline parameters in order to categorize participants. Also, using median values of cFGF-23 and sKlotho, participants were categorized into 4 groups, in whom survival was compared using Kaplan-Meier and Cox regression analysis. <b><i>Results:</i></b> 128 participants were enrolled with a median mGFR of 41.5 mL/min/1.73 m<sup>2</sup> (IQR = 28.2). Baseline mGFR correlated with cFGF-23 and sKlotho (<i>r</i> = −0.54 and <i>r</i> = 0.49, respectively; <i>p</i> &#x3c; 0.0001 for both). cFGF-23 and sKlotho levels correlated negatively (<i>r</i> = −0.24, <i>p</i> = 0.006). Multivariate regression tree analysis resulted in 3 groups defined by cutoff values of mGFR (60.9 mL/min/1.73 m<sup>2</sup>) and phosphate (3.7 mg/dL). These groups correlated with CKD stage, cFGF-23, and sKlotho (<i>p</i> &#x3c; 0.0001 for all). During a median follow-up of 36 months (IQR = 22), 40 (31.2%) participants reached the primary endpoint (31 initiated renal replacement therapy, 9 died). Survival to primary endpoint differed among the 4 groups formed using median values of both biomarkers, with the low FGF-23/high Klotho and high FGF-23/low Klotho having the longest and shortest survival, respectively. High FGF-23/low Klotho group, compared to the opposite one, had a significantly elevated risk of the primary outcome (HR, 6.8; 95% CI, 2.3–19.6; <i>p</i> = 0.0004). <b><i>Conclusions:</i></b> In patients with CKD stages 1–5, the combination of higher cFGF-23 and lower sKlotho levels along with mGFR and serum phosphate was associated with adverse clinical outcomes. The utility of combinations of traditional and novel biomarkers to predict outcomes warrants further study.

Atlantic cod (Gadus morhua) distribution response to environmental variability in the northern Gulf of St. Lawrence

2009 ◽  
Vol 66 (6) ◽  
pp. 909-918 ◽  
Author(s):  
Jonathan L.W. Ruppert ◽  
Marie-Josée Fortin ◽  
George A. Rose ◽  
Rodolphe Devillers
Keyword(s):  
Gadus Morhua ◽  
Environmental Variability ◽  
Atlantic Cod ◽  
Classification Tree ◽  
Regression Tree ◽  
Distribution Patterns ◽  
Classification And Regression Tree ◽  
Bottom Temperature ◽  
Tree Analysis ◽  
Regression Tree Analysis

Atlantic cod ( Gadus morhua ) distribution patterns and the behavioral (site fidelity), biotic (prey and predators), and environmental factors that determine them are fundamental to cod’s historic importance as a commercial species in the North Atlantic. Using classification and regression tree analysis (CART), we compared two periods (1991–1995 and 1998–2004) with contrasting bottom temperature and salinity regimes to determine regional factors that best explained cod distribution and catch weight per tow from summer surveys in the northern Gulf of St. Lawrence (the feeding period of cod). The classification tree analysis indicated that the presence or absence of cod was chiefly determined by depth in both of these periods. In contrast, the regression tree analysis determined that cod catch weight distributions were explained by different variables in each period. In the colder period (1991–1995), the distribution of catch weights was explained well by environmental variables (bottom temperature, salinity, depth); however, in the warmer period (1998–2004), distributions were best explained by variables from the previous year. These results indicate that the spatiotemporal dynamics of environmental conditions are likely to influence the loyalty of cod to specific feeding grounds and imply that cod responses to the environment could be susceptible to long-term environmental (e.g., bottom–habitat) and climate change.

scholarly journals Assessing Historical Fish Community Composition Using Surveys, Historical Collection Data, and Species Distribution Models

PLoS ONE ◽  
2011 ◽  
Vol 6 (9) ◽  
pp. e25145 ◽  
Author(s):  
Ben Labay ◽  
Adam E. Cohen ◽  
Blake Sissel ◽  
Dean A. Hendrickson ◽  
F. Douglas Martin ◽  
...  
Keyword(s):  
Community Composition ◽  
Species Distribution ◽  
Fish Community ◽  
Species Distribution Models ◽  
Distribution Models ◽  
Fish Community Composition ◽  
Collection Data
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