Scaling Bioconcentration and Pharmacokinetic Parameters for Body Size and Environmental Variables in Fish

2009 ◽  
pp. 149-149-17 ◽  
Author(s):  
WL Hayton ◽  
IR Schultz
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Pharmacokinetic Parameters

scholarly journals Response of Zooplankton Size Structure to Multiple Stressors in Urban Lakes

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2305
Author(s):  
Reliana Lumban Toruan ◽  
Liah X. Coggins ◽  
Anas Ghadouani
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Size Structure ◽  
Negative Slope ◽  
Total Biomass ◽  
Size Spectra ◽  
Urban Lakes ◽  
Chl A ◽  
Zooplankton Size ◽  
Density And Biomass

Urban lakes are important environmental assets that contribute significant ecosystem services in urbanised areas around the world. Consequently, urban lakes are more exposed to anthropogenic pressures. Zooplankton communities play a central role in lake processes and, as such, are very sensitive to the impacts of human activities both through in-lake and catchment processes. Understanding their ecological function in urban lakes and how they respond to urbanisation is essential for environmental sustainability. In this study, we investigated the reliability of zooplankton size structure as indicators of anthropogenic stressors in urban lakes. We examined the relationship between environmental variables and zooplankton community size spectra derived as mean body size, density, and biomass. Our study showed that the overall mean body size was within the small size group ranged from 416 to 735 µm equivalent spherical diameter (ESD). Despite no significant difference in total zooplankton density between lakes, there was variability in the total density of the five different size classes. Total biomass was characterised by a significant proportion of size >750 µm. As the specific parameter of normalised biomass size spectra (NBSS), the slopes of the NBSS varied from moderate (−0.83 to −1.04) for a community with higher biomass of the larger size zooplankton to steeper slopes (from −1.15 to −1.49) for a community with higher biomass of smaller size. The environmental variables, represented by total phosphorus (TP) and chlorophyll a (chl-a), had a strong effect on zooplankton biomass and NBSS, where TP and chl-a were significantly correlated with the increase of total biomass and corresponded well with a less negative slope. Our results indicated that the community metric was sensitive to nutrient input and that size-based metrics have the potential to serve as key indicators for the management of urban lakes.

Body Size Variation of European Storm PetrelsHydrobates pelagicusin Relation to Environmental Variables

2014 ◽  
Vol 49 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Dariusz Jakubas ◽  
Katarzyna Wojczulanis-Jakubas ◽  
Jens-Kjeld Jensen
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Size Variation ◽  
Body Size Variation

Correlational analyses of the relationships between altitude and carapace size of Ostracoda (Crustacea)

2020 ◽  
Vol 56 ◽  
pp. 2
Author(s):  
Enes Dalgakıran ◽  
Okan Külköylüoğlu ◽  
Mehmet Yavuzatmaca ◽  
Derya Akdemir
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Linear Relationship ◽  
Environmental Variables ◽  
New Records ◽  
Strong Tendency ◽  
Aquatic Habitats ◽  
The Mean ◽  
The Relationship

To explore the relationship between ostracods carapace (body) size and altitude, 117 non-marine aquatic habitats were sampled from Mersin province (Turkey) during 03–09 October 2015. A total of 36 species and 14 sub-fossils were detected from 66 of 117 sites located between −3 m and 1630 m a.s.l. Thirty-four of the species are previously unknown in the province. In addition, four of the taxa were new records for the Turkish Ostracoda fauna. Five species (Ilyocypris bradyi, Heterocypris salina, H. incongruens, Psychrodromus olivaceus, Potamocypris fallax) were the most common among all habitats with relatively wide ecological and altitudinal ranges. Canonical correspondence analyses revealed 72.6% of the relationship between 12 ostracods and five environmental variables. Water temperature and pH were the two most influential variables (p < 0.05) on the species. The mean length of right and left valves of the species were significantly different (p < 0.01, N  =  3980) at all altitudinal ranges. A strong tendency of changes in valve height with increasing altitude seems to be more prominent (p < 0.05) than the changes in length for some species. Our results do not support some ecological rules but rather, suggest that a linear relationship between carapace size and altitude may only be applicable for some ostracods.

scholarly journals Relationships of Vancomycin Pharmacokinetics to Body Size and Composition Using a Novel Pharmacomorphomic Approach Based on Medical Imaging

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Manjunath P. Pai ◽  
Brian A. Derstine ◽  
Matt Lichty ◽  
Brian E. Ross ◽  
June A. Sullivan ◽  
...  
Keyword(s):  
Body Size ◽  
Lumbar Vertebrae ◽  
Central Compartment ◽  
Volume Of Distribution ◽  
Coefficient Of Determination ◽  
Pharmacokinetic Parameters ◽  
Dose Selection ◽  
Body Depth ◽  
Computed Tomography Images ◽  
Volume Coefficient

ABSTRACT Antibiotics such as vancomycin are empirically dosed on the basis of body weight, which may not be optimal across the expanding adult body size distribution. Our aim was to compare the relationships between morphomic parameters generated from computed tomography images to conventional body size metrics as predictors of vancomycin pharmacokinetics (PK). This single-center retrospective study included 300 patients with 1,622 vancomycin concentration (52% trough) measurements. Bayesian estimation was used to compute individual vancomycin volume of distribution of the central compartment (Vc) and clearance (CL). Approximately 45% of patients were obese with an overall median (5th, 95th percentile) weight and body mass index of 87.2 (54.7, 123) kg and 28.8 (18.9, 43.7) kg/m2, respectively. Morphomic parameters of body size such as body depth, total body area, and torso volume of the twelfth thoracic through fourth lumbar vertebrae (T12 to L4) correlated with Vc. The relationship of vancomycin Vc was poorly predicted by body size but was stronger with T12-to-L4 torso volume (coefficient of determination [R 2] = 0.11) than weight (R 2 = 0.04). No relationships between vancomycin CL and traditional body size metrics could be discerned; however, relationships with skeletal muscle volume and total psoas area were found. Vancomycin CL independently correlated with total psoas area and inversely correlated with age. Thus, vancomycin CL was significantly related to total psoas area over age (R 2 = 0.23, P < 0.0001). This proof-of-concept study suggests a potential role for translation of radiographic information into parameters predictive of drug pharmacokinetics. Prediction of individual antimicrobial pharmacokinetic parameters using analytic morphomics has the potential to improve antimicrobial dose selection and outcomes of obese patients.

scholarly journals Normal fat mass cannot be reliably estimated in typical pharmacokinetic studies

2020 ◽  
Author(s):  
Roeland E. Wasmann ◽  
Elin M. Svensson ◽  
Stein J. Schalkwijk ◽  
Roger J. Brüggemann ◽  
Rob ter Heine
Keyword(s):  
Body Size ◽  
Fat Mass ◽  
Total Body Weight ◽  
Fat Free Mass ◽  
Pharmacokinetic Parameters ◽  
Parameter Estimates ◽  
Pharmacokinetic Studies ◽  
Careful Study ◽  
Case Scenario ◽  
True Value

Abstract Purpose An influential covariate for pharmacokinetics is (body) size. Recently, the method of estimation of normal fat mass (NFM) has been advocated. Here, the relative contribution of fat mass, estimated as a fraction fat (Ffat), is used to explain differences in pharmacokinetic parameters. This concept is more and more applied. However, it remains unclear whether NFM can be reliably estimated in these typical studies. Methods We performed an evaluation of the reliability of NFM estimation in a typical study size (n = 30), otherwise best-case scenario, by means of a pharmacokinetic simulation study. Several values of Ffat were investigated. Results In a typical pharmacokinetic study, high imprecision was observed for NFM parameter estimates over a range of scenarios. For example, in a scenario where the true value of Ffat on clearance was 0.5, we found a 95% confidence interval of − 0.1 to 2.1, demonstrating a low precision. The implications for practice are that one could conclude that fat-free mass best describes the relationship of the pharmacokinetics with body size, while the true relationship was between fat-free mass and total body weight. Consequently, this could lead to incorrect extrapolation of pharmacokinetics to extreme body sizes. Conclusion In typical pharmacokinetic studies, NFM should be used with caution because the Ffat estimates have low precision. The estimation of Ffat should always be preceded by careful study design evaluation before planning a study, to ensure that the design and sample size is sufficient to apply this potentially useful methodology.

Is body size variation in the platypus (Ornithorhynchus anatinus) associated with environmental variables?

2011 ◽  
Vol 59 (4) ◽  
pp. 201 ◽  
Author(s):  
Elise Furlan ◽  
J. Griffiths ◽  
N. Gust ◽  
R. Armistead ◽  
P. Mitrovski ◽  
...  
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Size Variation ◽  
The Body ◽  
Body Size Variation ◽  
Temperature Regimes ◽  
Ornithorhynchus Anatinus ◽  
Eastern Australia ◽  
Lower Temperature ◽  
Latitudinal Range

The body size of the platypus (Ornithorhynchus anatinus) is known to vary across both its latitudinal range and relatively short geographic distances. Here we consider how variation in platypus length and weight associates with environmental variables throughout the species’ range. Based on data from over 800 individuals, a Bergmann’s cline (increased body size in regions of lower temperature) was detected across the species latitudinal range. The opposite association, however, was present at smaller scales when comparing platypus body size and temperature within southern mainland Australia, or within an individual river basin. Temperature regimes alone clearly did not dictate body size in platypuses, although disentangling the effects of different climatic variables on body size variation was difficult because of correlations amongst variables. Nevertheless, within suitable platypus habitat in south-eastern Australia, areas of relatively lower rainfall and higher temperatures were typically associated with larger-bodied platypuses. The potential benefits to larger-bodied animals living under these conditions are explored, including consideration of variation in energy expenditure and food availability. Assuming these associations with environmental variables are biologically significant, a shift in platypus body size is anticipated in the future with predicted changes in climate.

scholarly journals Linking mean body size of pelagic Cladocera to environmental variables in Precambrian Shield lakes: A paleolimnological approach

2008 ◽  
Vol 67 (1) ◽  
pp. 22 ◽  
Author(s):  
Jennifer B. KOROSI ◽  
Andrew M. PATERSON ◽  
Anna M. DESELLAS ◽  
John P. SMOL
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Precambrian Shield ◽  
Shield Lakes

scholarly journals Size variation of morphological traits in Bosmina freyi and its relation with environmental variables in a tropical eutrophic reservoir

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1763-1769
Author(s):  
Yury Catalina López-Cardona ◽  
Edison Parra-García ◽  
Jaime Palacio-Baena ◽  
Silvia Lucía Villabona-González
Keyword(s):  
Body Size ◽  
Environmental Variables ◽  
Morphological Traits ◽  
Size Structure ◽  
Small Body ◽  
Size Variation ◽  
Zooplankton Community ◽  
The Body ◽  
Zooplankton Community Structure ◽  
Heterogeneous Distribution

We assessed the size variation of morphological traits in Bosmina freyi regarding changes in environmental variables, the biomass of invertebrate predators, and algal food availability in two depths of the photic zone, the riverine zone, and near the dam zone (lacustrine zone) in The Riogrande II reservoir. In 200 individuals of B. freyi, using the software TpsDig2 we measured the body size, mucron and antennule lengths, and the antennule aperture percentage. Using the Mann-Whitney U test, we assessed the differences between these traits considering the zones and the photic depths; however, we used a canonical discriminant analysis with morphologic traits and environmental variables. Measured morphological traits showed a heterogeneous distribution between sampled zones and depths (p < 0.05). The highest values mucron and antennule lengths and the smallest antennule aperture angle were observed on small body size individuals, associated with physical, chemical, and biological characteristics in the riverine zone and the subsurface. Size structure distribution in B. freyi was related to changes in water temperature, trophic state, depredation, availability, and quality of food, of which implications related to the zooplankton community structure, predator-prey relations, and energy flow in the reservoir.

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