scholarly journals Glide analysis and bone strength tests indicate powered flight capabilities in hatchling pterosaurs

2017 ◽  
Author(s):  
Mark P Witton ◽  
Elizabeth Martin-Silverstone ◽  
Darren Naish
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Bone Strength ◽  
Bending Strength ◽  
Skeletal Development ◽  
Maximum Size ◽  
Strength Analysis ◽  
Life Stages ◽  
Strength Tests ◽  
Very High

Pterosaur embryos and ‘hatchling’ specimens show a surprising level of skeletal development including well-ossified skeletons and large wings. This has prompted interpretations of pterosaurs as being flight-capable from the earliest ontogenetic stages, contrasting them against the majority of other flying animals, living or extinct. Though popular, this hypothesis is not universally accepted. Some authors propose that pterosaurs only became flight capable once they reached 50% of maximum size, explaining a slowing of growth rate in later ontogeny as metabolic resources were diverted into an energy-demanding form of locomotion. We investigated these hypotheses through glide performance and wing bone strength analysis on hatchling-grade specimens of two pterosaurs, Pterodaustro guinazui and Sinopterus dongi. We found that hatchling pterosaurs were excellent gliders, but with a wing ecomorphology more comparable to powered fliers than obligate gliders. Bone strength analysis shows that hatchling pterosaur wing bones are structurally identical to those of larger pterosaurs and – because of their very low body masses – their bending strength relative to body weight is very high, comparable to or exceeding the greatest values estimated for larger, more mature pterosaurs. Hatchling pterosaurs are thus as mechanically adapted to powered flight stresses as other pterosaurs, if not moreso. Together with our glide tests, this result supports interpretations of hatchling pterosaurs as flight-capable. Size differences between pterosaur hatchlings and larger members of their species dictate differences in wing ecomorphology and flight capabilities at different life stages, which might have bearing on pterosaur ontogenetic niching.

scholarly journals Glide analysis and bone strength tests indicate powered flight capabilities in hatchling pterosaurs

2017 ◽  
Author(s):  
Mark P Witton ◽  
Elizabeth Martin-Silverstone ◽  
Darren Naish
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Bone Strength ◽  
Bending Strength ◽  
Skeletal Development ◽  
Maximum Size ◽  
Strength Analysis ◽  
Life Stages ◽  
Strength Tests ◽  
Very High

Pterosaur embryos and ‘hatchling’ specimens show a surprising level of skeletal development including well-ossified skeletons and large wings. This has prompted interpretations of pterosaurs as being flight-capable from the earliest ontogenetic stages, contrasting them against the majority of other flying animals, living or extinct. Though popular, this hypothesis is not universally accepted. Some authors propose that pterosaurs only became flight capable once they reached 50% of maximum size, explaining a slowing of growth rate in later ontogeny as metabolic resources were diverted into an energy-demanding form of locomotion. We investigated these hypotheses through glide performance and wing bone strength analysis on hatchling-grade specimens of two pterosaurs, Pterodaustro guinazui and Sinopterus dongi. We found that hatchling pterosaurs were excellent gliders, but with a wing ecomorphology more comparable to powered fliers than obligate gliders. Bone strength analysis shows that hatchling pterosaur wing bones are structurally identical to those of larger pterosaurs and – because of their very low body masses – their bending strength relative to body weight is very high, comparable to or exceeding the greatest values estimated for larger, more mature pterosaurs. Hatchling pterosaurs are thus as mechanically adapted to powered flight stresses as other pterosaurs, if not moreso. Together with our glide tests, this result supports interpretations of hatchling pterosaurs as flight-capable. Size differences between pterosaur hatchlings and larger members of their species dictate differences in wing ecomorphology and flight capabilities at different life stages, which might have bearing on pterosaur ontogenetic niching.

scholarly journals Understanding the Interaction Effects between Dietary Lipid Content and Rearing Temperature on Growth Performance, Feed Utilization, and Fat Deposition of Sea Bass (Dicentrarchus labrax)

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 392
Author(s):  
Lydia Katsika ◽  
Mario Huesca Flores ◽  
Yannis Kotzamanis ◽  
Alicia Estevez ◽  
Stavros Chatzifotis
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Specific Growth ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Dietary Lipid ◽  
Lipid Levels ◽  
Final Body Weight ◽  
Temperature Regimes ◽  
Fish Group

This study was conducted to elucidate the interaction effects of temperature and dietary lipid levels (2 × 2 factorial experiment) on the growth performance, muscle, and liver composition in adult farmed European sea bass (Dicentrarchus labrax). Two groups of fish (190 g; 60 fish per group) were distributed in 12 tanks in triplicates and kept at two different temperature regimes; one starting at 23 °C and then changed to 17 °C for 61 days, and the other starting at 17 °C and then changed to 23 °C for 39 days. Two commercial diets containing both ~44% crude protein but incorporating different dietary lipid levels, 16.5% (D16) and 20.0% (D20) (dry matter (DM)), were fed to the fish to apparent satiation; the type of diet fed to each fish group remained constant throughout the experiment. Final body weight, weight gain, and specific growth rate were significantly higher for the fish group held at 23 °C compared to the fish group at 17 °C (before the temperature changes), while the dietary fat content did not have any profound effect in both groups. Furthermore, the different temperature regimes did not affect muscle or liver composition, but, on the contrary, dietary lipids affected hepatosomatic, perivisceral fat, and visceral indexes. Feed conversion ratio and specific growth rate were not affected by the dietary lipid level. An interaction of temperature and dietary lipid content was observed in daily feed consumption (DFC) and final body weight (FBW).

scholarly journals Robustness of life histories to environmental variability in complex versus simple life cycles

2021 ◽  
Author(s):  
Annie Jonsson
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Environmental Variability ◽  
Life Cycles ◽  
Relative Advantage ◽  
Complex Life Cycle ◽  
Life Stages ◽  
Vital Rates ◽  
Habitat Separation ◽  
Simple Life

AbstractMost animal species have a complex life cycle (CLC) with metamorphosis. It is thus of interest to examine possible benefits of such life histories. The prevailing view is that CLC represents an adaptation for genetic decoupling of juvenile and adult traits, thereby allowing life stages to respond independently to different selective forces. Here I propose an additional potential advantage of CLCs that is, decreased variance in population growth rate due to habitat separation of life stages. Habitat separation of pre- and post-metamorphic stages means that the stages will experience different regimes of environmental variability. This is in contrast to species with simple life cycles (SLC) whose life stages often occupy one and the same habitat. The correlation in the fluctuations of the vital rates of life stages is therefore likely to be weaker in complex than in simple life cycles. By a theoretical framework using an analytical approach, I have (1) derived the relative advantage, in terms of long-run growth rate, of CLC over SLC phenotypes for a broad spectrum of life histories, and (2) explored which life histories that benefit most by a CLC, that is avoid correlation in vital rates between life stages. The direction and magnitude of gain depended on life history type and fluctuating vital rate. One implication of our study is that species with CLCs should, on average, be more robust to increased environmental variability caused by global warming than species with SLCs.

scholarly journals In Vivo Radioprotective Activity of Cell-Permeable Bifunctional Antioxidant Enzyme GST-TAT-SOD against Whole-Body Ionizing Irradiation in Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jianru Pan ◽  
Huocong He ◽  
Ying Su ◽  
Guangjin Zheng ◽  
Junxin Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Antioxidant Activity ◽  
Body Weight ◽  
Whole Body ◽  
White Pulp ◽  
Radioprotective Activity ◽  
Significant Difference ◽  
Wbc Count

GST-TAT-SOD was the fusion of superoxide dismutase (SOD), cell-permeable peptide TAT, and glutathione-S-transferase (GST). It was proved to be a potential selective radioprotector in vitro in our previous work. This study evaluated the in vivo radioprotective activity of GST-TAT-SOD against whole-body irradiation. We demonstrated that intraperitoneal injection of 0.5 ml GST-TAT-SOD (2 kU/ml) 2 h before the 6 Gy whole-body irradiation in mice almost completely prevented the splenic damage. It could significantly enhance the splenic antioxidant activity which kept the number of splenic white pulp and consequently resisted the shrinkage of the spleen. Moreover, the thymus index, hepatic antioxidant activity, and white blood cell (WBC) count of peripheral blood in irradiated mice pretreated with GST-TAT-SOD also remarkably increased. Although the treated and untreated irradiated mice showed no significant difference in the growth rate of animal body weight at 7 days postirradiation, the highest growth rate of body weight was observed in the GST-TAT-SOD-pretreated group. Furthermore, GST-TAT-SOD pretreatment increased resistance against 8 Gy whole-body irradiation and enhanced 30 d survival. The overall effect of GST-TAT-SOD seemed to be a bit more powerful than that of amifostine. In conclusion, GST-TAT-SOD would be a safe and potentially promising radioprotector.

scholarly journals Effects of Preventive Acupuncture and Moxibustion on Fat Accumulation, Blood Lipid, and UterusE2of Menopause Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shi-Peng Zhu ◽  
Yu-wei He ◽  
Huan Chen ◽  
Zhi-Fang Sun ◽  
Na Ding ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Density Lipoprotein ◽  
Blood Lipid ◽  
Control Group ◽  
Young Control ◽  
Fat Accumulation ◽  
Acupuncture And Moxibustion ◽  
Weight Growth ◽  
Sd Rats

Objective. To observe the effect of preventive acupuncture and moxibustion on blood lipid of menopause rats.Methods. Seventy 10-month-old SD rats with estrous cycle disorders were divided into three control groups and four treatment groups (n=10/group) and another ten 3.5-month-old female SD rats were chosen as young control group. Preventive acupuncture and moxibustion were applied at Guanyuan (CV 4). Body weight growth rate has been recorded. Plasma total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), and high density lipoprotein (HDL) levels and uterusE2level were measured.Results. Compared to young control group, plasma TC and LDL increased and uterusE2reduced significantly in 12-month-old control group. Compared to 12-month-old control group, plasma TC and LDL level and body weight growth rate decreased while HDL level increased remarkably in preventive acupuncture 12-month-old group. Compared to 14-month-old control group, plasma TC level and body weight growth rate decreased remarkably in preventive moxibustion 14-month-old group.Conclusions. Preventive acupuncture and moxibustion can significantly decrease the plasma TG and LDL, increase the plasma HDL, and prevent fat accumulation. Our finding suggests that preventive acupuncture and moxibustion have beneficial effects on blood lipid. Different treatment effects were found between preventive acupuncture and preventive moxibustion.

A comparison of the effects of infection with Eimeria maxima and dietary restriction on weight gain, plasma metabolites and liver glycogen in the immature fowl, Gallus domesticus

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 205-213 ◽  
Author(s):  
H. D. Chapman ◽  
D. L. Fernandes ◽  
T. F. Davison
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Uric Acid ◽  
Weight Gain ◽  
Food Intake ◽  
Acute Phase ◽  
Plasma Glucose ◽  
Liver Glycogen ◽  
Plasma Metabolites ◽  
Eimeria Maxima

SUMMARYThe effects of Eimeria maxima or restricted pair-feeding on weight gain, plasma concentrations of protein, glucose, free fatty acids (FFA) and uric acid and liver glycogen were compared in immature fowl. Food intake/kg body weight and weight gain decreased during the acute phase of infection (days 5–7) while weight loss was prolonged for an extra day compared with pair-fed birds. During recovery, food intake/kg body weight of infected birds was greater than that of non-infected controls but there was no evidence for an increase in growth rate compared with controls when body weight was considered. Growth rate of pair-fed birds was greater than that of infected birds during recovery, indicating their better use of ingested food. Liver glycogen and plasma protein concentration were decreased during the acute phase of infection but the concentrations of plasma glucose, free fatty acid (FFA) and uric acid were not affected. In pair-fed birds liver glycogen was depleted, concentrations of plasma glucose and uric acid decreased and FFA increased, and these changes persisted for the remainder of the experiment. The findings are similar to those in birds whose food has been withheld and were probably due to the pattern of food intake imposed by the experimental protocol. It is concluded that the metabolic differences between infected and pair-fed birds are of doubtful significance.

Very High Growth Rate of 4H-SiC Using MTS as Chloride-Based Precursor

2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Dependence ◽  
Growth Rates ◽  
Molar Fraction ◽  
High Growth ◽  
High Growth Rate ◽  
Epitaxial Layers ◽  
Single Precursor ◽  
Very High

The chlorinated precursor methyltrichlorosilane (MTS), CH3SiCl3, has been used to grow epitaxial layers of 4H-SiC in a hot wall CVD reactor, with growth rates as high as 170 µm/h at 1600°C. Since MTS contains both silicon and carbon, with the C/Si ratio 1, MTS was used both as single precursor and mixed with silane or ethylene to study the effect of the C/Si and Cl/Si ratios on growth rate and doping of the epitaxial layers. When using only MTS as precursor, the growth rate showed a linear dependence on the MTS molar fraction in the reactor up to about 100 µm/h. The growth rate dropped for C/Si < 1 but was constant for C/Si > 1. Further, the growth rate decreased with lower Cl/Si ratio.

scholarly journals Analysis of the coefficient of variation in shear and tensile bond strength tests

2005 ◽  
Vol 13 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Fábio Lourenço Romano ◽  
Gláucia Maria Bovi Ambrosano ◽  
Maria Beatriz Borges de Araújo Magnani ◽  
Darcy Flávio Nouer
Keyword(s):  
Coefficient Of Variation ◽  
Mean Value ◽  
Scientific Article ◽  
A Value ◽  
Statistical Analysis System ◽  
Strength Tests ◽  
Analysis System ◽  
Very High

The coefficient of variation is a dispersion measurement that does not depend on the unit scales, thus allowing the comparison of experimental results involving different variables. Its calculation is crucial for the adhesive experiments performed in laboratories because both precision and reliability can be verified. The aim of this study was to evaluate and to suggest a classification of the coefficient variation (CV) for in vitro experiments on shear and tensile strengths. The experiments were performed in laboratory by fifty international and national studies on adhesion materials. Statistical data allowing the estimation of the coefficient of variation was gathered from each scientific article since none of them had such a measurement previously calculated. Excel worksheet was used for organizing the data while the sample normality was tested by using Shapiro Wilk tests (alpha = 0.05) and the Statistical Analysis System software (SAS). A mean value of 6.11 (SD = 1.83) for the coefficient of variation was found by the data analysis and the data had a normal distribution (p>0.05). A range classification was proposed for the coefficient of variation from such data, that is, it should be considered low for a value lesser than 2.44; intermediate for a value between 2.44 and 7.94, high for a value between 7.94 and 9.78, and finally, very high for a value greater than 9.78. Such classification can be used as a guide for experiments on adhesion materials, thus making the planning easier as well as revealing precision and validity concerning the data.

RESPONSE OF EARLY WEANED PIGS TO DIETS OF DIFFERENT DIGESTIBLE ENERGY CONCENTRATIONS AND THE EFFECTS OF CEREAL SOURCE AND ADDED MOLASSES ON PERFORMANCE

1972 ◽  
Vol 52 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J. F. O’GRADY ◽  
J. P. BOWLAND
Keyword(s):  
Growth Rate ◽  
G Protein ◽  
Dietary Protein ◽  
Lower Energy ◽  
Energy Levels ◽  
Constant Ratio ◽  
Initial Weight ◽  
N Retention ◽  
Digestible Energy ◽  
Very High

One hundred and sixty pigs weaned at 2 weeks were allotted at an average initial weight of 3.8 kg to two experiments to examine the effects of diets based on barley or wheat as the cereal component and having digestible energy (DE) concentrations ranging from 2.8 to 3.6 Mcal/kg. Protein was in constant ratio to DE (15.2 kcal DE/g protein). Very high mortality was experienced on the lower energy levels, although the inclusion of 5% molasses in the formulation reduced mortality. Among surviving pigs, growth rate was significantly reduced at lower energy concentrations. The optimum DE level for maximum gain was 3.2 Mcal in the first experiment and 3.4 Mcal/kg in the second. The efficiency of utilization of DE for growth was best at a DE concentration of 3.2 Mcal/kg in the first experiment but did not vary in the second. Digestibility of dietary protein increased with increasing dietary DE but nitrogen (N) retention as percentage of N intake or of digestible N was not significantly influenced by DE in the diet.

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