Determinants of species abundance in the Quaternary vertebrate fossil record

Paleobiology ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 537-546 ◽  
Author(s):  
Samuel T. Turvey ◽  
Tim M. Blackburn
Keyword(s):  
Body Mass ◽  
Species Abundance ◽  
Ecological Factors ◽  
General Applicability ◽  
Data Set ◽  
Terrestrial Vertebrate ◽  
Wide Range ◽  
Holocene Record ◽  
Independent Calibration ◽  
The Relationship

Species abundance data are of vital importance in paleontology, but fossil accumulations invariably represent a biased subset of original source communities. Efforts to quantify taphonomic biases are typically prevented by a lack of independent data on the ecological composition of prehistoric faunas. However, analysis of the continental Holocene record can provide a rare opportunity for independent calibration of fossil abundance patterns. We analyzed a comprehensive data set available for the Holocene avifauna of Sweden to investigate the relationship between species abundance in the recent fossil and zooarchaeological records and in prehistoric source communities, and to characterize the importance of different ecological factors in determining terrestrial vertebrate fossil abundances. The number of assemblages in which species occurred was compared with modern-day species abundance, annual residence, body mass, and ecological realm. Modern-day abundance is only one of several significant predictors of fossil abundance; the strongest predictor is body mass, and Holocene species abundance can be interpreted as a measure of species abundance in source communities for a given size class only. Our study represents one of the only direct attempts to quantify species abundance biases between fossil faunas and source communities, and has general applicability for a wide range of terrestrial vertebrate faunas.

scholarly journals Body mass index as a measure of body fatness: age- and sex-specific prediction formulas

1991 ◽  
Vol 65 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Paul Deurenberg ◽  
Jan A. Weststrate ◽  
Jaap C. Seidell
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Body Fat ◽  
Prediction Error ◽  
Bioelectrical Impedance ◽  
Skinfold Thickness ◽  
Fat Percentage ◽  
Wide Range ◽  
The Relationship ◽  
Age And Sex

In 1229 subjects, 521 males and 708 females, with a wide range in body mass index (BMI; 13.9–40.9 kg/m2), and an age range of 7–83 years, body composition was determined by densitometry and anthropometry. The relationship between densitometrically-determined body fat percentage (BF%) and BMI, taking age and sex (males =1, females = 0) into account, was analysed. For children aged 15 years and younger, the relationship differed from that in adults, due to the height-related increase in BMI in children. In children the BF% could be predicted by the formula BF% = 1.51xBMI–0.70xage–3.6xsex+1.4 (R2 0.38, SE of estimate (see) 4.4% BF%). In adults the prediction formula was: BF% = 1.20xBMI+0.23xage−10.8xsex–5.4 (R2 0.79, see = 4.1% BF%). Internal and external cross-validation of the prediction formulas showed that they gave valid estimates of body fat in males and females at all ages. In obese subjects however, the prediction formulas slightly overestimated the BF%. The prediction error is comparable to the prediction error obtained with other methods of estimating BF%, such as skinfold thickness measurements or bioelectrical impedance.

scholarly journals Persistence of dry matter yield among New Zealand perennial ryegrass (Lolium perenne L.) cultivars: insights from a long-term data set

2015 ◽  
Vol 77 ◽  
pp. 177-184 ◽  
Author(s):  
D.F. Chapman ◽  
P.D. Muir ◽  
M.J. Faville
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Heading Date ◽  
Early Years ◽  
Grass Species ◽  
Data Set ◽  
High Performing ◽  
Wide Range ◽  
The Relationship

Persistence of herbage yield is an important productivity trait of grass species and cultivars in New Zealand pastures. However, relatively little is known about genetic variation in this trait, principally because few studies comparing yield have continued beyond 3 years. This paper reports results from a comparison of 25 perennial ryegrass cultivars representing a wide range of functional types and genetic backgrounds conducted under sheep grazing in a summer-dry environment. Dry matter (DM) yield was measured for the first 3 years after sowing, then again in years seven and eight post-sowing, and in year ten post-sowing. Endophyte DNA fingerprinting conducted mid-way through year seven confirmed that, with one exception, ryegrass populations remained true-to-type in the cultivars sown with novel endophyte strains. The cultivar effect on DM yield was statistically significant in all measurement periods. Differences in yields among cultivars in years seven and eight were significantly and positively correlated with yield differences in years one to three (r=0.685 to 0.831 depending on which year contrasts were used). Thus, high-performing cultivars in the early years of the trial were also generally highperforming cultivars in years seven and eight, and vice-versa, indicating a high degree of yield stability in perennial ryegrass cultivars. Yield differences did not appear to be related to differences in cultivar heading date, ploidy, endophyte status, or genetic background. The relationship between yield in year ten and yields in years one to three was much weaker (r=0.392) than the relationship in years seven and eight. Possible reasons for this are discussed. Keywords: Perennial ryegrass; traits; persistence

scholarly journals Oxygen Consumption and Ammonia Excretion of Marphysa sanguinea (Polychaeta: Eunicidae) in Relation to Body Mass and Temperature

Fishes ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 52
Author(s):  
Chengjian Wang ◽  
Na Kou ◽  
Xiaowei Liu ◽  
Dazuo Yang
Keyword(s):  
Activation Energy ◽  
Oxygen Consumption ◽  
Body Mass ◽  
Economic Value ◽  
Ammonia Excretion ◽  
Ecological Factors ◽  
Different Temperatures ◽  
Animal Metabolism ◽  
The Relationship ◽  
Marphysa Sanguinea

(1) Background: Marphysa sanguinea is a polychaete with high economic value and ecological importance. Information on metabolism is important to understand the physiological action of organisms. (2) Methods: The rates of oxygen consumption (R) and ammonia excretion (U) were measured using different temperatures (T) and body mass (M) levels. The activation energy (E) was calculated using the universal temperature dependence theory. (3) Results: Oxygen consumption presented a curve with an upward trend first, and then a downward trend, and ammonia excretion displayed a “U” curve. The effects of temperature and body size on oxygen consumption and ammonia excretion rates were extremely significant. Small individuals had higher metabolic rates than large polychaetes at the same temperature. The relationship between oxygen consumption, ammonia excretion, and M was expressed as Y = a·Mb, bR = 0.56 ± 0.09, and bU = 0.35 ± 0.30. The oxygen consumption activation energy was ER = 0.68 eV, and the ammonia excretion activation energy was EU = 0.53 eV. The O:N ratio at different temperatures and body sizes was in the range of 3.55–56.44. (4) Conclusions: The results not only provide basic data on the metabolism of M. sanguinea but also insights to understand the relationship between animal metabolism and ecological factors from different perspectives.

A comparison of the relationship between measured acoustic response and porosity in carbonates across different geologic periods, depositional basins, and with variable mineral composition

2018 ◽  
Vol 6 (2) ◽  
pp. T245-T256
Author(s):  
Beth Vanden Berg ◽  
Christophe Nussbaumer ◽  
Amy Noack ◽  
John Thornton ◽  
Ralf J. Weger ◽  
...  
Keyword(s):  
Carbonate Platform ◽  
Order Estimate ◽  
Michigan Basin ◽  
Limited Data ◽  
Data Set ◽  
Paradox Basin ◽  
Great Bahama Bank ◽  
Wide Range ◽  
Basic Relationship ◽  
The Relationship

Recent work has shown that there is a predictable inverse relationship between laboratory-measured sonic velocity response and porosity in carbonates, which can be reasonably approximated using the empirical Wyllie time-average equation (WTA). The relationship was initially identified in late Cretaceous to Cenozoic age samples collected from the Great Bahama Bank and the Maiella Platform, an exhumed Cretaceous carbonate platform in Italy. We have compared older carbonate samples from different basins and different geologic ages to determine the applicability of this relationship and subsequent correlations to key petrophysical properties to other carbonate basins and other geologic time periods. The data set used for the comparison shows this relationship to be relatively consistent in other depositional basins (Michigan Basin, Paradox Basin) and with samples from older geologic periods (Pennsylvanian, Ordovician, and Mississippian). However, this basic relationship is also observed to vary significantly within a reservoir system and within a depositional basin in samples from different geologic periods (e.g., Silurian- versus Ordovician-age rocks in the Michigan Basin). Although the empirical WTA can generally be applied as a first-order estimate across a wide range of sample ages in carbonates, limited data suggest the relationship between velocity and porosity to be moderately more complex. For instance, in unconventional carbonate reservoirs characterized by predominantly micro- to nanoscale porosity, it is observed that the WTA should be applied as an upper data boundary. In addition, this study has shown that the relationship to the dominant pore type is less direct than in a macropore system in which it can be assumed that the dominant pore type also has the greatest effect on the effective permeability.

scholarly journals An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

2014 ◽  
Author(s):  
Charles Frasier
Keyword(s):  
Regression Analysis ◽  
Metabolic Rate ◽  
Body Mass ◽  
Characteristic Length ◽  
Data Set ◽  
Homogeneous Groups ◽  
Mass Data ◽  
Length Data ◽  
Unexplained Variance ◽  
The Relationship

The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically predicts the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(body mass)b. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that predict BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measurable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidae is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can exactly predict every BMR and mass datum from the BMR and mass data set with no error and thus no unexplained variance. Furthermore MMLE can exactly predict every body mass and length datum from the mass and length data set with no error and thus no unexplained variance. Whether or not MMLE can simultaneously exactly predict an individual animal’s BMR and body mass given its characteristic length awaits analysis of a data set that simultaneously reports all three of these items for individual animals. However for many of the addressed phylogenetic homogeneous groups, MMLE can predict the exponent obtained by regression analysis of the BMR and mass data using the exponent obtained by regression analysis of the mass and length data. This argues that MMLE may be able to accurately simultaneously predict BMR and mass for an individual animal.

scholarly journals Ecological Factors of Transmission, Persistence and Circulation of Pathogens In Bat Populations

2019 ◽  
Vol 63 (1) ◽  
pp. 32-40
Author(s):  
S. Zemanová ◽  
Ľ. Korytár ◽  
Z. Benkő ◽  
M. Prokeš ◽  
A. Ondrejková
Keyword(s):  
Infectious Diseases ◽  
Human Health ◽  
Current Knowledge ◽  
Emerging Infectious Diseases ◽  
Ecological Factors ◽  
Review Article ◽  
Wide Range ◽  
Ecological Roles ◽  
Viral Communities ◽  
The Relationship

Abstract The existence of bats is crucial for all ecosystem units as they fulfil numerous ecological roles. However, they are also considered to be natural reservoirs of a wide range of zoonotic microorganisms, especially viruses. In this review article we briefly summarize current knowledge about various ecological factors that facilitate bat pathogen dispersal and about the current approaches to monitoring viral communities present within bat populations. On the basis of the cited papers, we suggest that the increased focus on complex viral populations in bats and their interactions with other populations and the environment is necessary to fully comprehend the relationship between emerging infectious diseases, the environment and their toll on human health.

scholarly journals An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

2014 ◽  
Author(s):  
Charles Frasier
Keyword(s):  
Regression Analysis ◽  
Metabolic Rate ◽  
Body Mass ◽  
Characteristic Length ◽  
Data Set ◽  
Homogeneous Groups ◽  
Mass Data ◽  
Length Data ◽  
Unexplained Variance ◽  
The Relationship

The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically predicts the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(body mass)b. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that predict BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measurable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidae is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can exactly predict every BMR and mass datum from the BMR and mass data set with no error and thus no unexplained variance. Furthermore MMLE can exactly predict every body mass and length datum from the mass and length data set with no error and thus no unexplained variance. Whether or not MMLE can simultaneously exactly predict an individual animal’s BMR and body mass given its characteristic length awaits analysis of a data set that simultaneously reports all three of these items for individual animals. However for many of the addressed phylogenetic homogeneous groups, MMLE can predict the exponent obtained by regression analysis of the BMR and mass data using the exponent obtained by regression analysis of the mass and length data. This argues that MMLE may be able to accurately simultaneously predict BMR and mass for an individual animal.

scholarly journals A fast calibration approach for onboard LiDAR-camera systems

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142090960
Author(s):  
Shang Erke ◽  
Dai Bin ◽  
Nie Yiming ◽  
Xiao Liang ◽  
Zhu Qi
Keyword(s):  
Autonomous Navigation ◽  
Camera System ◽  
Camera Systems ◽  
Field Environment ◽  
Novel Approach ◽  
Wide Range ◽  
Independent Calibration ◽  
The Relationship ◽  
Calibration Approach ◽  
Robot Platform

Outdoor surveillance and security robots have a wide range of industrial, military, and civilian applications. In order to achieve autonomous navigation, the LiDAR-camera system is widely applied by outdoor surveillance and security robots. The calibration of the LiDAR-camera system is essential and important for robots to correctly acquire the scene information. This article proposes a fast calibration approach that is different from traditional calibration algorithms. The proposed approach combines two independent calibration processes, which are the calibration of LiDAR and the camera to robot platform, so as to address the relationship between LiDAR sensor and camera sensor. A novel approach to calibrate LiDAR to robot platform is applied to improve accuracy and robustness. A series of indoor experiments are carried out and the results show that the proposed approach is effective and efficient. At last, it is applied to our own outdoor security robot platform to detect both positive and negative obstacles in a field environment, in which two Velodyne-HDL-32 LiDARs and a color camera are employed. The real application illustrates the robustness performance of the proposed approach.

Optimum plant population densities for lupin (Lupinus angustifolius L.) in the wheatbelt of Western Australia

1994 ◽  
Vol 34 (4) ◽  
pp. 491 ◽  
Author(s):  
RJ French ◽  
K McCarthy ◽  
WL Smart
Keyword(s):  
Western Australia ◽  
Plant Population ◽  
Lupinus Angustifolius ◽  
Yield Potential ◽  
Asymptotic Model ◽  
Population Densities ◽  
Data Set ◽  
Optimum Density ◽  
Wide Range ◽  
The Relationship

Lupin (Lupinus angustifolius L.) seed yields at various plant population densities were studied in 33 separate experiments throughout the wheatbelt of Western Australia between 1987 and 1990. The experiments were designed to test the hypotheses that optimum plant population densities for lupins vary between environments and between cultivars. Another objective was the development of a framework for sowing rate recommendations from a large data set derived from sowing rate experiments. Two types of equation were fitted to each data set by nonlinear regression: one described an asymptotic response, the other a response where yield reached a maximum but declined at higher densities. The second type of equation was used to describe a data set if the residual mean square was significantly lower than for the asymptotic equation. In all, 122 individual responses were fitted, of these only 13 were not adequately described by the asymptotic model. Optimum density was chosen according to an economic criterion (when marginal revenue from an increase in plant population density equalled marginal cost). This was equivalent to choosing the point where the slope of the response curve was 0.004 t.m2/ha.plant (equivalent to 0.4 g/plant). Optimum density ranged from 14 to 138 plants/m2 and was linearly related to yield potential, which we defined as either the asymptotic yield value, or the maximum yield for responses that did not approach an asymptote. Yield potential ranged from 0.13 to 4.1 t/ha. The relationship between optimum density and yield potential was the same for cvv. Danja, Gungurru, and Yorrel, and for a reduced branching breeding line (75A/329). It was also the same on soils classified as good or poor for lupins. We suggest that the relationship between optimum density and yield potential will be useful in determining target plant densities for lupins under a wide range of conditions in Western Australia, and that the techniques should prove useful in producing recommendations from density experiments in other agricultural regions.

scholarly journals The relationship between self-employment and unemployment in the long-run

2016 ◽  
Vol 43 (3) ◽  
pp. 358-379 ◽  
Author(s):  
George Saridakis ◽  
Miguel Angel Mendoza ◽  
Rebeca I. Muñoz Torres ◽  
Jane Glover
Keyword(s):  
Design Methodology ◽  
Structural Breaks ◽  
Panel Cointegration ◽  
Data Set ◽  
Content Type ◽  
Self Employment ◽  
Long Run ◽  
Wide Range ◽  
Short Run ◽  
The Relationship

Purpose – Although a lot of research has been done on the link between self-employment and unemployment, often focusing on the short-run of the relationship, the long-run association between the two variables has not received adequate attention. The paper aims to discuss these issues. Design/methodology/approach – In this paper the authors examine the long-run relationship between self-employment and unemployment using panel cointegration methods allowing for structural breaks and covering a wide range of European OECD countries using the COMPENDIA data set over the period 1990-2011. Findings – The findings indicate that a long-run relationship between self-employment and unemployment exist in the panel, but the cointegrating coefficients are unstable. Originality/value – The estimates finds positive and statistically significant long-run association between self-employment and unemployment exists for more than 50 per cent of the countries included in the sample after the break. For the rest of the countries the authors find either negative or statistically insignificant association.

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