Notes on Allometry and Prediction of Body Mass and Age of Giraffes

2021 ◽  
pp. 76-84
Author(s):  
Graham Mitchell
Keyword(s):  
Body Mass ◽  
Great Accuracy ◽  
Rate Of Change ◽  
Biological Structures ◽  
Ontogenetic Allometry ◽  
Interspecific Allometry ◽  
Physiological And Biochemical

Quantification of how biological structures change during growth is essential for understanding how giraffes work. Allometry is the best arithmetical tool for analyzing changes that occur during growth. It measures how well the rate of change in one structure is associated with the rate of change in another in the species of interest. If the association is close, then allometry can be used, as in this chapter, to predict the age of a giraffe (from, say, its height) or its body mass (from its length and girth), with great accuracy. The best predictions are made if the data used to make predictions are derived from the particular species, and this type is referred to as ontogenetic allometry. A second type—interspecific allometry—uses data collected from other species to make predictions about the species of interest (like giraffes). Predictions using this second method are less accurate but are useful for establishing anatomical, physiological, and biochemical differences between the species of interest and all other comparable species.

scholarly journals One year change of knee cartilage morphology in the first release of participants from the Osteoarthritis Initiative progression subcohort: association with sex, body mass index, symptoms and radiographic osteoarthritis status

2008 ◽  
Vol 68 (5) ◽  
pp. 674-679 ◽  
Author(s):  
F Eckstein ◽  
S Maschek ◽  
W Wirth ◽  
M Hudelmaier ◽  
W Hitzl ◽  
...  
Keyword(s):  
Risk Factors ◽  
Body Mass Index ◽  
Body Mass ◽  
Statistical Significance ◽  
Weight Bearing ◽  
Rate Of Change ◽  
Cartilage Loss ◽  
Knee Oa ◽  
Symptomatic Knee ◽  
Osteoarthritis Initiative

Objective:The Osteoarthritis Initiative (OAI) is a multicentre study targeted at identifying biomarkers for evaluating the progression and risk factors of symptomatic knee OA. Here cartilage loss using 3 Tesla (3 T) MRI is analysed over 1 year in a subset of the OAI, together with its association with various risk factors.Methods:An age- and gender-stratified subsample of the OAI progression subcohort (79 women and 77 men, mean (SD) age 60.9 (9.9) years, body mass index (BMI) 30.3 (4.7)) with both frequent symptoms and radiographic OA in at least one knee was studied. Coronal FLASHwe (fast low angle shot with water excitation) MRIs of the right knee were acquired at 3 T. Seven readers segmented tibial and femoral cartilages blinded to order of acquisition. Segmentations were quality controlled by one expert.Results:The reduction in mean cartilage thickness (ThC) was greater (p = 0.004) in the medial than in the lateral compartment, greater (p = 0.001) in the medial femur (−1.9%) than in the medial tibia (−0.5%) and greater (p = 0.011) in the lateral tibia (−0.7%) than in the lateral femur (0.1%). Multifactorial analysis of variance did not reveal significant differences in the rate of change in ThC by sex, BMI, symptoms and radiographic knee OA status. Knees with Kellgren–Lawrence grade 2 or 3 and with a BMI >30 tended to display greater changes.Conclusions:In this sample of the OAI progression subcohort, the greatest, but overall very modest, rate of cartilage loss was observed in the weight-bearing medial femoral condyle. Knees with radiographic OA in obese participants showed trends towards higher rates of change than those of other participants, but these trends did not reach statistical significance.

Statistical Techniques for Interpreting Body Size–Related Exercise Performance during Growth

2000 ◽  
Vol 12 (2) ◽  
pp. 112-127 ◽  
Author(s):  
Joanne R. Welsman ◽  
Neil Armstrong
Keyword(s):  
Body Size ◽  
Linear Regression ◽  
Body Mass ◽  
Exercise Performance ◽  
Multilevel Regression ◽  
Cross Sectional ◽  
Regression Techniques ◽  
Ontogenetic Allometry ◽  
Log Linear ◽  
Individual Size

This paper reviews some of the statistical methods available for controlling for body size differences in the interpretation of developmental changes in exercise performance. For cross-sectional data analysis simple per body mass ratio scaling continues to be widely used, but is frequently ineffective as the computed ratio remains correlated with body mass. Linear regression techniques may distinguish group differences more appropriately but, as illustrated, only allometric (log-linear regression) scaling appropriately removes body size differences while accommodating the heteroscedasticity common in exercise performance data. The analysis and interpretation of longitudinal data within an allometric framework is complex. More established methods such as ontogenetic allometry allow insights into individual size-function relationships but are unable to describe adequately population effects or changes in the magnitude of the response. The recently developed multilevel regression modeling technique represents a flexible and sensitive solution to such problems allowing both individual and group responses to be modeled concurrently.

scholarly journals Rate of change in body mass index at different ages during childhood and adult obesity risk

2019 ◽  
Vol 14 (7) ◽  
pp. e12513 ◽  
Author(s):  
Tao Zhang ◽  
Paul K. Whelton ◽  
Bo Xi ◽  
Marie Krousel‐Wood ◽  
Lydia Bazzano ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Rate Of Change ◽  
Adult Obesity ◽  
Obesity Risk ◽  
Different Ages

scholarly journals Genetical studies on growth and form in the fowl 1. Phenotypic variation in the relative growth pattern of shank length and body-weight

1963 ◽  
Vol 4 (2) ◽  
pp. 167-192 ◽  
Author(s):  
A. G. Cock
Keyword(s):  
Body Weight ◽  
Rhode Island ◽  
Single Point ◽  
Regression Line ◽  
Rate Of Change ◽  
Relative Growth ◽  
Ontogenetic Allometry ◽  
Breed Crosses ◽  
Limits Of Error ◽  
Static Allometry

Body-weight and shank length from 2 weeks of age to adult (and from 8 weeks onwards, shank width) have been measured on 154 fowls all hatched on the same date, belonging to two F1 breed crosses: White Leghorn × Rhode Island Red (L × R) and Indian Game × Light Sussex (G × S). After logarithmic transformation the data have first been analysed cross-sectionally (analysis of the age-means for each sex and cross). A longitudinal analysis (fitting a regression line to the data of each individual) has then been made of the approximately linear portions of the curves. The following conclusions are drawn.(1) Growth in shank length relative to body-weight between 2 and 10 weeks conforms closely to simple allometry. The coefficient of ontogenetic allometry (heter-auxesis), k, is approximately 0·4, being 0·02 higher in L × R than in G × S and 0·05 higher in males than in females. In females k declines (eventually to zero) after 10 weeks; the decline occurs about 4 weeks later in males. For shank width relative to body-weight k is about 0·25.(2) At a given body-weight males have longer and thicker shanks than females; L × R have longer but thinner shanks than G × S.(3) Within sexes and crosses there is highly significant individual variation in k, but the allometry lines do not pass, within the limits of error, through any single point. This implies that variation in relative shank length is complex in its ontogenetic origin.(4) There is no appreciable correlation within sexes and crosses between shank width and shank length at a given body-weight; this implies (as does (2)) that variation is also complex anatomically.(5) Differences in shape and rate-of-change of shape contribute only a small part of the total variation within sexes and crosses; most is due to differences in general size and general growth rate.(6) Shank width at a given body-weight is positively correlated with body-weight at a given age (r = + 0·36 within sexes and crosses). This agrees with the finding that the coefficient of static allometry (allomorphosis) for shank width is much higher than the ontogenetic coefficient. For shank length the ontogenetic and static coefficients are approximately the same.

scholarly journals Ontogenetic Allometry of Body Height and Body Mass of Girl in Baduy, Indonesia

2018 ◽  
Vol 25 (3) ◽  
pp. 138
Author(s):  
Eneng Nunuz Rohmatullayaly ◽  
Alex Hartana ◽  
Yuzuru Hamada ◽  
Bambang Suryobroto
Keyword(s):  
Body Mass ◽  
Sexual Maturity ◽  
Developmental Plasticity ◽  
Body Height ◽  
The Body ◽  
Growth Trajectory ◽  
Growth Spurt ◽  
Small Scale ◽  
Age At Menarche ◽  
Ontogenetic Allometry

Several small-scale populations exhibited phenotypic plasticity whereby growth spurt of body height occurred much earlier than age at menarche and this was not followed by same early spurt of body weight. This leads to question whether growth trajectory of stature follow the same growth trajectory of body mass and whether the trajectory itself is associated to sexual maturity. We evaluated developmental plasticity observed in Baduy girl, a traditional population in Indonesia, in facing strenuous environmental and biocultural conditions. We measured stature and body mass cross-sectionally. We determined age at menarche as population average of age of girls that had already got their first menstruation. Growths of body fat and weight followed a same mode and timing and their spurts pivoted on the age at menarche. In contrast, growth spurt of body height occurred four years earlier than menarche and velocity curve of body linearity progressed in opposite direction to that of body ponderality. The prevailing poor nutrition and high physical activity elicited principle of ontogenetic allometry to synchronize the acceleration and deceleration of growths in body linearity and ponderality whereby growth in body height functions to reach the body size target and to provide skeletal framework for development of body mass. The biocultural conditions lead to slow bodily growth rate with low spurt resulting in the characteristics of Baduy girl that was small in size and late in both sexual maturity and full-grown ages.

scholarly journals Vocal traits of shorebird chicks are related to body mass and sex

2022 ◽  
Author(s):  
Kristal Nicole Kostoglou ◽  
Edward H Miller ◽  
Michael A Weston ◽  
David R Wilson
Keyword(s):  
Body Mass ◽  
Frequency Modulation ◽  
Sexual Difference ◽  
Dominant Frequency ◽  
Rate Of Change ◽  
Antipredator Behaviour ◽  
Frequency Range ◽  
Time Intervals ◽  
Call Structure ◽  
Precocial Birds

Acoustic communication is critical during early life phases in precocial birds. For example, adult alarm calls can elicit antipredator behaviour in young, and chick vocalisations can communicate information to parents about chick identity, condition, location, sex, or age. We investigated whether chick calls of two species of Australian Charadriidae vary with sex or body mass. We handled Red-capped Plover Charadrius ruficapillus and Southern Masked Lapwing Vanellus miles novaehollandiae chicks for purposes of measurement, blood sampling, and banding. We opportunistically recorded their distress calls while in the hand, and analysed the calls to determine whether call structure is related to sex or body mass (a proxy for age). We measured five traits per call, plus time intervals between successive calls, for 26 plover chicks (2600 calls) and 95 lapwing chicks (6835 calls). In plovers, inter-call intervals were shorter in males and both inter-call interval and the dominant frequency range of calls decreased with increasing body mass. In lapwings, frequency modulation (computed as the range in the rate of change of the dominant frequency) was lower in male calls. The dominant frequency range of lapwing calls decreased with mass in both sexes, but the decline was greater in males, resulting in a lower dominant frequency range in males. Frequency modulation and entropy of lapwing calls also decreased with increasing body mass. Minimum dominant frequency did not change with body mass or sex in either species. Our study provides the first evidence for charadriid chicks of (a) a sexual difference in call structure and rate and (b) gradual growth-related changes in call structure and rate, across chicks. Studies on calls from a greater range of chick ages and from more species within this large and diverse family would be valuable. We provide a foundation for further studies of shorebird vocalisations during growth, which may elucidate the development and functional significance of such vocalisations.

scholarly journals Physical Activity Matters: Associations Among Body Mass Index, Physical Activity, and Health-Related Quality of Life Trajectories Over 10 Years

2014 ◽  
Vol 11 (7) ◽  
pp. 1265-1275 ◽  
Author(s):  
David Feeny ◽  
Rochelle Garner ◽  
Julie Bernier ◽  
Amanda Thompson ◽  
Bentson H. McFarland ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Physical Activity ◽  
Body Mass Index ◽  
Body Mass ◽  
Leisure Time ◽  
Rate Of Change ◽  
Health Related Quality ◽  
Related Quality ◽  
Health Related

Background:The objective of this study was to assess the associations among body mass index (BMI), leisure time physical activity (LTPA) and health-related quality of life (HRQL) trajectories among adults.Methods:Self-reported data were drawn from the Canadian National Population Health Survey, with respondents being interviewed every 2 years between 1996–97 and 2006–07. Using growth curve modeling, HRQL trajectories for individuals aged 18 and over were associated with measures of BMI and LTPA. Growth models were constructed separately for males and females.Results:Findings suggested that, for males, BMI categories had little impact on baseline HRQL, and no impact on the rate of change in HRQL. Among women, higher BMI categories were associated with significantly lower baseline HRQL. However, BMI had no impact on the rate of change of HRQL. Conversely, for both men and women and regardless of BMI category, LTPA had significant impacts on baseline HRQL, as well as the rate of change in HRQL. Individuals who were inactive or sedentary had much steeper declines in HRQL as they aged, as compared with individuals who were active in their leisure time.Conclusions:The results underscore the importance of LTPA in shaping trajectories of HRQL.

scholarly journals The impact of PIT tags on the growth and survival of pythons is insignificant in randomised controlled trial

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11531
Author(s):  
Patrick L. Taggart ◽  
Stephen Morris ◽  
Charles G.B. Caraguel
Keyword(s):  
Randomised Controlled Trial ◽  
Body Mass ◽  
Body Condition ◽  
Controlled Trial ◽  
Rate Of Change ◽  
Individual Identification ◽  
Pit Tags ◽  
Randomised Controlled ◽  
Pit Tagging ◽  
The Impact

Individual identification is fundamental to the study of captive and wild animals but can have adverse impacts if the method of identification is inappropriate for the species or question of interest. We conducted a randomised controlled trial to test whether passive integrated transponder (PIT) tags reduced the growth or survival of pythons. We randomly allocated 200 captive-bred Burmese python (Python bivittatus) hatchlings into two groups, tagged versus untagged. Hatchlings were individually identified using a combination of PIT tags and unique colour patterns, and their mass, snout-vent length (SVL) and body condition measured at 9, 73, 134, 220, 292 and 385 days of age. We recorded the date of all mortalities. Python morphometrics and their rate of change increased or fluctuated non-linearly with age. The impact of PIT tagging on python body mass and body mass growth over the 376 day study period was insignificant. PIT tagging additionally had an insignificant impact on python survival. However, we found minor differences in SVL growth between tagged and untagged pythons. These differences peaked at approximately 0.5 mm/day and appeared to drive similar, but more pronounced, differences between tagged and untagged pythons in their rate of change in body condition; peaking at approximately 3–4 g/day. While we cannot be certain that these small differences are, or are not, biologically meaningful, they nonetheless appear to be short-term and readily resolved. Unsurprisingly, the strongest driver of python growth was their age, with growth rapidly increasing or highest amongst younger snakes for all measures of size. Python sex was associated with their body mass and survival, with higher mass but lower survival amongst females. Python size at hatching did not impact on their growth or survival. Our results confirm that PIT tags are a valuable and effective tool for the identification and tracking of captive pythons, and snakes generally, and meet high safety and animal welfare standards.

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