scholarly journals Movement responses to environment: fast inference of variation among southern elephant seals with a mixed effects model

Ecology ◽  
2018 ◽  
Vol 100 (1) ◽  
Author(s):  
I. D. Jonsen ◽  
C. R. McMahon ◽  
T. A. Patterson ◽  
M. Auger‐Méthé ◽  
R. Harcourt ◽  
...  
Keyword(s):  
Mixed Effects ◽  
Mixed Effects Model ◽  
Elephant Seals ◽  
Southern Elephant Seals

scholarly journals Movement responses to environment: fast inference of variation among southern elephant seals with a mixed effects model

2018 ◽  
Author(s):  
I. D. Jonsen ◽  
C. R. McMahon ◽  
T. A. Patterson ◽  
M. Auger-Méthé ◽  
R. Harcourt ◽  
...  
Keyword(s):  
Sea Ice ◽  
Movement Patterns ◽  
Elephant Seal ◽  
Mixed Effects ◽  
Foraging Strategies ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
Movement Model ◽  
Elephant Seals ◽  
Southern Elephant Seals

AbstractLike many species, movement patterns of southern elephant seals (Mirounga leonina) are being influenced by long-term environmental change. These seals migrate up to 4000 km from their breeding colonies, foraging for months in a variety of Southern Ocean habitats. Understanding how movement patterns vary with environmental features and how these relationships differ among individuals employing different foraging strategies can provide insight into foraging performance at a population level. We apply new fast-estimation tools to fit mixed effects within a random walk movement model, rapidly inferring among-individual variability in southern elephant seal environment-movement relationships. We found that seals making foraging trips to the sea-ice on or near the Antarctic continental shelf consistently reduced speed and directionality (move persistence) with increasing sea ice coverage and had variable responses to chlorophyll a concentration, whereas seals that foraged pelagically reduced move persistence in regions where circumpolar deep water shoaled. Given future climate scenarios, pelagic foragers may encounter more productive habitat but sea-ice foragers may see reduced habitat availability. Our approach is scalable to large telemetry data sets and allows flexible combinations of mixed effects to be evaluated via model selection, thereby illuminating the ecological context of animal movements that underlie habitat use.

Serological screening for Brucella spp. and Leptospira spp. antibodies in southern elephant seals Mirounga leonina from Elephant Island, Antarctica, in 2003 and 2004

2020 ◽  
Vol 142 ◽  
pp. 161-170
Author(s):  
AM Sánchez-Sarmiento ◽  
V Ruoppolo ◽  
MMC Muelbert ◽  
JS Ferreira Neto ◽  
JL Catão-Dias
Keyword(s):  
Austral Summer ◽  
Agglutination Test ◽  
South Shetland Islands ◽  
Climate Change Scenarios ◽  
Mirounga Leonina ◽  
Serological Screening ◽  
Elephant Seals ◽  
Southern Elephant Seals ◽  
Monitoring And Surveillance ◽  
Elephant Island

Brucella spp. and Leptospira spp. antibodies were surveyed in 35 southern elephant seals (SESs) Mirounga leonina at Elephant Island (South Shetland Islands), western Antarctic peninsula, in the Austral summer of 2003 and 2004. The rose Bengal test and a commercial competitive ELISA (c-ELISA) were used to detect Brucella spp. exposure, and the microscopic agglutination test (MAT) with 22 live serovars was used to determine anti-Leptospira spp. antibodies. We found evidence of Brucella spp. exposure in 3 of 35 (8.6%) SESs tested via the c-ELISA displaying high percentage inhibition (PI), similar to other studies in pinnipeds in which Brucella spp. antibodies have been determined. Two of the 3 positives were pups (PI = 70.4 and 86.6%), while the third was an adult female (PI = 48.8%). The 3 c-ELISA positive SESs were additionally tested via the serum agglutination test but were found to be negative. All individuals were negative for antibodies against 22 Leptospira spp. serovars by MAT. These results contribute to the knowledge and monitoring of zoonotic pathogens with epizootic potential in Southern Ocean pinnipeds. Given the potential impact that pathogens may have on the abundance of wild (sometimes threatened and endangered) populations, constant monitoring and surveillance are required to prevent pathogen spread, particularly under forecast climate change scenarios.

scholarly journals A flexible nonlinear mixed effects model for HIV viral load rebound after treatment interruption

2020 ◽  
Vol 39 (15) ◽  
pp. 2051-2066 ◽  
Author(s):  
Rui Wang ◽  
Ante Bing ◽  
Cathy Wang ◽  
Yuchen Hu ◽  
Ronald J. Bosch ◽  
...  
Keyword(s):  
Viral Load ◽  
Treatment Interruption ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Nonlinear Mixed Effects ◽  
Hiv Viral Load ◽  
Nonlinear Mixed Effects Model ◽  
Viral Load Rebound

scholarly journals The state of Spanish /s/ variation in Concepción, Chile: Linguistic and social trends

2020 ◽  
Vol 6 (1) ◽  
pp. 132-153
Author(s):  
Brandon M. A. Rogers
Keyword(s):  
Social Factors ◽  
Central City ◽  
Mixed Effects ◽  
The State ◽  
Mixed Effects Model ◽  
Proportional Odds ◽  
Random Factor ◽  
Social Trends ◽  
Southern Central ◽  
Social Demographics

AbstractThe current study examines /s/ variation in the southern-central city of Concepción, Chile and its relation to a variety of linguistic and social factors. A proportional-odds mixed effects model, with the random factor of “speaker”, was used to treat the categorically coded data on a continuum of acoustical variation ([s] > [h] > ∅). The results presented show that contrary to the previous assertions, heavy sibilant reduction, especially elision, in Concepción, Chile is the rule, rather than the exception, to the extent that it is no longer a marker of certain social demographics as has been reported previously. Furthermore, based on the trends reported, it is likely that this has been the case for several decades. Finally, the overall observed trends are indicative that the rates of /s/ elision will continue to increase across social demographics and different phonetic and phonological contexts in Concepción, Chile.

Estimating local arterial stiffness using mixed-effects model-based residuals: a novel approach

2021 ◽  
Author(s):  
Avinash Chandran ◽  
Derek W. Brown ◽  
Gabriel H. Zieff ◽  
Zachary Y. Kerr ◽  
Daniel Credeur ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Model Based ◽  
Novel Approach
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