An Allometric Model for Pesticide Bioaccumulation

1982 ◽  
Vol 39 (5) ◽  
pp. 727-735 ◽  
Author(s):  
Sara Griesbach ◽  
Robert Henry Peters ◽  
Sami Youakim
Keyword(s):  
Body Size ◽  
Trophic Level ◽  
Field Experiments ◽  
Body Burden ◽  
Allometric Model ◽  
Operational Approach ◽  
Natural Systems ◽  
Empirical Relations ◽  
Body Sizes ◽  
Qualitative Similarity

A combination of the frequency distribution of body sizes and appropriate allometric relationships may permit a more operational approach to pesticide bioaccumulation than the more traditional trophic level concept. To demonstrate this potential, we describe patterns of bioaccumulation as functions of time and body size in a computer ecosystem in which no differences in trophic level exist. The qualitative similarity between these patterns and those reported in the literature from laboratory and field experiments suggests that empirical relations describing contaminant fluxes as functions of body weight could form a powerful base for the prediction of contaminant body burden in natural systems. We believe this approach could prove useful for any persistent contaminant with high biological affinity.Key words: modeling, bioaccumulation, ecological magnification, allometry, body size

Size-dependent predation alters interactions between parasites and predators

2016 ◽  
Vol 94 (9) ◽  
pp. 631-635 ◽  
Author(s):  
S.V.L. Catania ◽  
J. Koprivnikar ◽  
S.J. McCauley
Keyword(s):  
Body Size ◽  
Trophic Levels ◽  
Freshwater Systems ◽  
Natural Systems ◽  
Selective Foraging ◽  
Top Predators ◽  
Foraging Preferences ◽  
Body Sizes ◽  
Infectious Stage ◽  
Host Infection

Increasing evidence indicates that parasites play an important role within many systems as prey for higher trophic levels. Predation on parasites can decrease their numbers and may affect host infection rates. Cercariae, a free-living infectious stage of trematode parasites, are abundant in freshwater systems and are directly consumed by a number of freshwater predators. However, few studies have tested whether predators exhibit a preference for cercariae when alternative prey are available or how these preferences vary across predator body sizes. We assessed whether dragonfly larvae (dot-tailed whiteface, Leucorrhinia intacta (Hagen, 1861)), top predators in freshwater systems without fish, foraged preferentially when presented with two prey types, cercariae and zooplankton, and whether foraging preferences changed across predator body size. Body size of larval dragonfly predators was found to be significantly, and negatively, related to the fraction of cercariae in the diet. Larger bodied dragonfly larvae shifted their diet choice from cercariae to zooplankton. Changes in foraging selectivity as body size increases across a predator’s ontogeny can alter the strength of predator–prey interactions. Further investigation into size-selective foraging on parasites may provide new insights into the effects of predation on parasite abundance and transmission in natural systems.

scholarly journals A Farewell to the Encephalization Quotient: A New Brain Size Measure for Comparative Primate Cognition

2021 ◽  
pp. 1-12
Author(s):  
Carel P. van Schaik ◽  
Zegni Triki ◽  
Redouan Bshary ◽  
Sandra A. Heldstab
Keyword(s):  
Body Size ◽  
Cognitive Abilities ◽  
Brain Size ◽  
Estimation Error ◽  
Primate Species ◽  
Mammal Species ◽  
Mean Values ◽  
Encephalization Quotient ◽  
Body Sizes ◽  
Size Measure

Both absolute and relative brain sizes vary greatly among and within the major vertebrate lineages. Scientists have long debated how larger brains in primates and hominins translate into greater cognitive performance, and in particular how to control for the relationship between the noncognitive functions of the brain and body size. One solution to this problem is to establish the slope of cognitive equivalence, i.e., the line connecting organisms with an identical bauplan but different body sizes. The original approach to estimate this slope through intraspecific regressions was abandoned after it became clear that it generated slopes that were too low by an unknown margin due to estimation error. Here, we revisit this method. We control for the error problem by focusing on highly dimorphic primate species with large sample sizes and fitting a line through the mean values for adult females and males. We obtain the best estimate for the slope of circa 0.27, a value much lower than those constructed using all mammal species and close to the value expected based on the genetic correlation between brain size and body size. We also find that the estimate of cognitive brain size based on cognitive equivalence fits empirical cognitive studies better than the encephalization quotient, which should therefore be avoided in future studies on primates and presumably mammals and birds in general. The use of residuals from the line of cognitive equivalence may change conclusions concerning the cognitive abilities of extant and extinct primate species, including hominins.

scholarly journals Density and body size of the larval stages of the invasive golden mussel (Limnoperna fortunei) in two neotropical rivers

2012 ◽  
Vol 23 (3) ◽  
pp. 282-292 ◽  
Author(s):  
Vivianne Eilers ◽  
Márcia Divina de Oliveira ◽  
Kennedy Francis Roche
Keyword(s):  
Body Size ◽  
Larval Stage ◽  
Larval Density ◽  
Limnoperna Fortunei ◽  
Larval Size ◽  
Larval Stages ◽  
Positive Effects ◽  
Paraguay River ◽  
Body Sizes ◽  
Golden Mussel

AIM: The present study involved an analysis of the monthly variations in the population densities and body sizes of the different stages of planktonic larvae of the invasive golden mussel (Limnoperna fortunei), in the rivers Paraguay and Miranda; METHODS: The study was carried out between February 2004 and January 2005. Monthly collection of the plankton samples was accompanied by physical, chemical and biological analyses of the water; RESULTS: The Miranda River presented higher values of calcium, pH, alkalinity, conductivity and total phosphorous. Larval density varied from 0-24 individuals.L-1 in the Paraguay River, with a peak in March of 2004, while in the Miranda River, densities varied between 0-9 individuals.L-1 with a peak in February of 2004. No larvae were encountered during the coldest months, May and June. No significant correlations were found between environmental variables and larval density in either river. Only the valved larval stages were recorded. The "D" and veliger forms were most abundant; umbonate larvae were rare in the Miranda River samples. Mean body sizes of "D", veliger and umbonate larval stages were, respectively, 111, 135 and 152 µm, in the Paraguay River, and 112, 134 and 154 µm in the Miranda River. Principal Components Analysis indicated positive relationships between "D" larval stage size and the ratio between inorganic and organic suspended solids, while negative relationships were found between larval size and calcium and chlorophyll-<img border=0 width=7 height=8 src="/img/revistas/alb/2012nahead/ALB_AOP_230307car01.jpg">; CONCLUSIONS: The larvae were recorded in the plankton during most of the year, with the exception of the two colder months. Neither densities nor larval stage body sizes were significantly different between the two rivers. Possible positive effects of food and calcium concentrations on body size were not recorded. This species may be adapted to grow in environments with elevated sediment concentrations.

scholarly journals Body Size Preferences and Food Choice Among Normal and Overweight Mothers and Children in Malawi (P10-070-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Valerie Flax ◽  
Chrissie Thakwalakwa ◽  
Lindsay Jaacks ◽  
John Phuka
Keyword(s):  
Body Size ◽  
Food Choice ◽  
Weight Status ◽  
Food Choices ◽  
Normal Weight ◽  
Sub Saharan Africa ◽  
Overweight Child ◽  
Mothers And Children ◽  
Body Sizes ◽  
Healthy Body

Abstract Objectives Overweight in mothers and children in sub-Saharan Africa is rapidly increasing and may be related to body size preferences. The objective of this study was to measure mothers’ preferences for their own and their child's body size and how they relate to food choices. Methods We enrolled 271 mothers and their children (6–59 months) in Lilongwe and Kasungu Districts. Based on standard body-mass index and weight-for-height z-score cutoffs, 78 mothers (29%) were normal weight and 193 (71%) were overweight; 120 children (44%) were normal weight and 151 (56%) were overweight. Interviewers used a set of 7 adult female and 7 child body silhouette drawings and a semi-structured question guide to measure mothers’ perceptions of their own and their child's preferred and healthy body sizes and how their preferences affected food choices. We performed chi-squared tests comparing body size perceptions and grouped open-ended responses by weight status. Results Mothers’ selection of silhouettes that represented their body size preferences (67% normal weight, 68% overweight preferred overweight) and perceptions of a healthy body size (96% normal weight, 94% overweight selected overweight as healthy) did not differ by their weight status. A higher percentage of mothers of overweight than normal weight children preferred overweight child body sizes (70% vs. 48%, P = 0.003). Mothers’ perceptions of a healthy child body size (89% normal weight, 94% overweight selected overweight as healthy) did not differ by the child's weight status. To attain a larger body size, mothers said they could eat or feed the child larger quantities or more frequently and increase consumption of fatty/oily foods and drinks (such as sodas, sweetened yoghurt, and milk), but many cannot afford to do this. Conclusions Malawian mothers had strong preferences for overweight body sizes for themselves and mixed preferences for their children. Their desired strategies for increasing weight indicate that body size preferences may drive food choice but could be limited by cost. Funding Sources Drivers of Food Choice (DFC) Competitive Grants Program, funded by the UK Government's Department for International Development and the Bill & Melinda Gates Foundation, and managed by the University of South Carolina, Arnold School of Public Health.

Serum Levels of Melatonin in Cancer Patients and their Relation to Body Sizes

1988 ◽  
Vol 3 (3) ◽  
pp. 193-196 ◽  
Author(s):  
S. Barni ◽  
P. Lissoni ◽  
S. Crispino ◽  
F. Rovelli ◽  
G. Esposti ◽  
...  
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Cancer Patients ◽  
Serum Levels ◽  
Blood Levels ◽  
Melatonin Secretion ◽  
Normal Range ◽  
Blood Concentrations ◽  
Patients With Cancer ◽  
Body Sizes

Melatonin secretion is often enhanced in patients with cancer. In the light of a reported correlation between melatonin levels and body size, we investigated blood levels of this pineal hormone in a group of 72 patients affected by cancer, 30 of whom had body weight within the normal range, 30 were obese and the last 12 cases had body weight below the normal range, in order to establish whether in fact melatonin blood concentrations were related to body size. Melatonin levels were high in 19/72 patients (26%). The mean levels of the pineal hormone were similar in patients with normal, low and high body weight. Finally, there was no significant correlation between melatonin values and body weight, height or surface. Melatonin secretion thus does not appear to be influenced by body size in cancer patients.

scholarly journals Evidence for continent-wide convergent evolution and stasis throughout 150 years of a biological invasion

2021 ◽  
Author(s):  
Yihan Wu ◽  
Robert I Colautti
Keyword(s):  
Adaptive Evolution ◽  
Fossil Record ◽  
Field Experiments ◽  
Common Garden ◽  
Lythrum Salicaria ◽  
Natural Systems ◽  
Continental Scale ◽  
Evolutionary Response ◽  
Temperature Records ◽  
Growing Conditions

The extent to which evolution can rescue a species from extinction, or facilitate range expansion, depends critically on the rate, duration, and geographical extent of the evolutionary response to natural selection. While field experiments have demonstrated that adaptive evolution can occur quickly, our understanding of the duration and geographical extent of contemporary evolution in natural systems remains limited. This is particularly true for species with large geographical ranges and for timescales that lie between 'long-term' field experiments and the fossil record. Here, we introduce the Virtual Common Garden (VCG) to estimate genetic differences among phenotypes observed in natural history collections. Reconstructing 150 years of evolution in Lythrum salicaria (purple loosestrife) as it invaded across North America, we analyze phenology measurements of 3,429 herbarium records, reconstruct growing conditions from more than 12 million local temperature records, and validate predictions across three common gardens spanning 10 degrees of latitude. We find that phenology evolves rapidly and repeatedly along parallel climatic gradients during the first century of evolution. However, the rate of microevolution stalls thereafter, recapitulating macroevolutionary stasis observed in the fossil record. Our study demonstrates why preserved specimens are a critical resource for understanding limits to evolution in natural. Our results show predictability of evolution emerging at a continental scale across 15 decades of rapid, adaptive evolution.

scholarly journals The body-size dependence of mutual interference

2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Size Dependence ◽  
Empirical Support ◽  
Mutual Interference ◽  
The Body ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Body Sizes ◽  
Size Scales

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.

scholarly journals Information use during movement regulates how fragmentation and loss of habitat affect body size

2018 ◽  
Vol 285 (1884) ◽  
pp. 20180953 ◽  
Author(s):  
Jasmijn Hillaert ◽  
Martijn L. Vandegehuchte ◽  
Thomas Hovestadt ◽  
Dries Bonte
Keyword(s):  
Body Size ◽  
Evolutionary Dynamics ◽  
Information Use ◽  
Spatial Arrangement ◽  
Habitat Choice ◽  
Spatially Explicit ◽  
Spatially Explicit Model ◽  
Feedback Effects ◽  
Body Sizes ◽  
Movement Ability

An individual's body size is central to its behaviour and physiology, and tightly linked to its movement ability. The spatial arrangement of resources and a consumer's capacity to locate them are therefore expected to exert strong selection on consumer body size. We investigated the evolutionary impact of both the fragmentation and loss of habitat on consumer body size and its feedback effects on resource distribution, under varying levels of information used during habitat choice. We developed a mechanistic, individual-based, spatially explicit model, including several allometric rules for key consumer traits. Our model reveals that as resources become more fragmented and scarce, informed habitat choice selects for larger body sizes while random habitat choice promotes small sizes. Information use may thus be an overlooked explanation for the observed variation in body size responses to habitat fragmentation. Moreover, we find that resources can accumulate and aggregate if information about resource abundance is incomplete. Informed movement results in stable resource–consumer dynamics and controlled resources across space. However, habitat loss and fragmentation destabilize local dynamics and disturb resource suppression by the consumer. Considering information use during movement is thus critical to understand the eco-evolutionary dynamics underlying the functioning and structuring of consumer communities.

Girth body dimensions in men and women with seborrheic dermatitis of varying severity

2021 ◽  
Vol 27 (4) ◽  
pp. 22-27
Author(s):  
Ahmad Raed Khasawneh ◽  
I.V. Serheta ◽  
N.V. Belik ◽  
A.O. Dovhan ◽  
I.I. Zhuchenko
Keyword(s):  
Body Size ◽  
Seborrheic Dermatitis ◽  
Severe Disease ◽  
Statistical Processing ◽  
Modern Medicine ◽  
The Body ◽  
Control Group ◽  
Men And Women ◽  
Healthy Men ◽  
Body Sizes

Today in modern medicine the study of human health is reoriented to the individual principle, which is based on the identification and study of constitutionally determined patterns of manifestation of certain diseases. The purpose of the study is to establish and analyze the features of the girth body sizes in men and women with generalized fatty form of seborrheic dermatitis of varying severity. The comprehensive body size of 40 men and 40 young women (25-44 years) with generalized fatty seborrheic dermatitis (mild and severe) was determined. The control group consisted of the girth sizes of practically healthy men (n=82) and women (n=154) of the same age group, which were selected from the database of the research center National Pirogov Memorial Medical University. Statistical processing of body circumference was performed in the licensed package “Statistica 6.0” using non-parametric evaluation methods. As a result of studies in patients with seborrheic dermatitis of varying severity of men, compared with practically healthy men, found only greater values of the girth of the shoulder in a relaxed state and thighs, neck (only mild), shin in the upper part and waist (in both cases only with a severe degree), as well as smaller values of the girth of the shoulder in a tense state; and in patients of varying severity of women – greater values of the girth of the shoulder in a relaxed state, thighs, lower legs, neck, waist and all girths of the chest and both thighs (only severe), as well as smaller values of the girth of the hand (only with mild). In both men and women with seborrheic dermatitis, differences in girth body sizes are more pronounced in people with severe disease. Between men or women with seborrheic dermatitis of varying severity, there are no significant or trends in differences in girth body sizes. In the analysis of the manifestations of sexual dimorphism of the circumferential body size between men and women with seborrheic dermatitis found greater values in men with mild and severe disease of the upper extremities, hands, shin, feet and neck (in most cases more pronounced in representatives with mild severity), as well as only in men with mild severity – greater values of all chest girths. For a more correct understanding of changes in girth body sizes in Ukrainian men or women with seborrheic dermatitis of varying severity, it is necessary to analyze other constitutional parameters of the body.

‘Photography’ as a useful method for estimating the density, sex-ratio and body size of the surface-active Austruca perplexa (H. Milne Edwards, 1852) (Brachyura, Ocypodidae)

Crustaceana ◽  
2021 ◽  
Vol 94 (11-12) ◽  
pp. 1429-1440
Author(s):  
Kanitta Keeratipattarakarn ◽  
Fahmida Wazed Tina ◽  
Rattapon Sangngam ◽  
Ketsanee Thongsri ◽  
Arreeya Suphap
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Fiddler Crab ◽  
Body Sizes ◽  
Crab Density ◽  
Surface Active ◽  
Non Destructive ◽  
Photography Method

Abstract Estimations of crab density, sex-ratio, and body sizes are difficult. Though the ‘burrow excavation’ method is widely used to estimate these parameters in surface-active crabs, it is destructive to crab populations. Therefore, an alternative, non-destructive method is desirable. This study compared the non-destructive ‘photography’ method with the ‘burrow excavation’ method in a fiddler crab (Austruca perplexa (H. Milne Edwards, 1852)) population. Twenty 0.25 m2 quadrats were set out and 4 photos were taken of the surface-active crabs in each quadrat. All crab burrows were then excavated, and the crabs were collected to estimate their numbers, sexes, and body and claw sizes. Afterward, the photographs were analysed to estimate the same parameters by using the GIMP program. These parameters were then compared between the two methods. The results showed that these parameters were not different between the methods compared. This study thus reveals that the ‘photography’ method could safely be used instead of the ‘burrow excavation’ method, and yield the same results.

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