Movement patterns of lacertid lizards: effects of temperature on speed, pauses and gait in Lacerta vivipara

1989 ◽  
Vol 10 (1) ◽  
pp. 77-84 ◽  
Author(s):  
R.A. Avery ◽  
D.J. Bond
Keyword(s):  
Movement Patterns ◽  
Duty Factor ◽  
Lacertid Lizards ◽  
Activity Temperature ◽  
The Mean ◽  
Effects Of Temperature ◽  
Lacerta Vivipara ◽  
Simultaneous Movement

AbstractLacerta vivipara emerging from their overnight retreat before they had the opportunity to thermorcgulate moved with an alternation of locomotor bursts and pauses. Mean speed during bursts of locomotion fell with decreasing temperature from 3.21 snout-vent lengths (SVL) s-1 at the activity temperature (Tact ∼ 33°C) to 0.15 SVL s-1 at 5°C. Between Tact and 19°C the reduction was small (Q10 = 1.12) and statistically not significant; between 19°C and 5°C the change was very much greater (Q10 = 7.7). The pauses between locomotor bursts increased progressively in duration over the whole range of decreasing temperatures from Tact to 5°C, although the change from Tact to 23°C was not significant. Gait changed progressively from almost simultaneous movement of contralateral diagonal limbs at Tact to independent movement of limbs in the sequence LF, RH, RF, LH at 7°C, with increases in the mean duty factor of individual feet from 0.50 to 0.76 and in the proportion of time for which 3 or 4 feet were in simultaneous contact with the ground from 0 to 0.92.

scholarly journals Movement patterns of humpback whales (Megaptera novaeangliae) reoccupying a Brazilian breeding ground

2018 ◽  
Vol 18 (4) ◽  
Author(s):  
Maria Isabel Carvalho Gonçalves ◽  
Renata Santoro de Sousa-Lima ◽  
Niel Nascimento Teixeira ◽  
Gustavo Henrique Carvalho ◽  
Daniel Danilewicz ◽  
...  
Keyword(s):  
Group Composition ◽  
Movement Patterns ◽  
Study Groups ◽  
Humpback Whales ◽  
Suitable Habitat ◽  
Behavioral State ◽  
Energy Conserving ◽  
Wintering Area ◽  
The Mean ◽  
Feeding Grounds

Abstract: The population of humpback whales from breeding stock A is increasing, and little is known about the routes used by humpbacks that move north of the main calving area of Brazil, the Abrolhos Bank. The aim of this study was to describe the movements of humpback whales in a reoccupation wintering area (Serra Grande, Bahia state, Brazil) based on land-based surveys to test if movement patterns change during the season and between years, due to group composition, behavioral state, and distance to the coast. The mean leg speed of the groups sighted was 6.88 (±2.92) km/h, and leg speed was positively correlated with distance to the coast. There was an increase in leg speed and distance to the coast with increasing number of escorts in the groups with calves. The mean linearity value for group trajectory was 0.81 (±0.19) and the mean reorientation rate was 25.72 (±19.09) º/min. We observed a predominance of trajectories heading south throughout the study. Groups exhibiting more erratic movements early in the season, and groups moving south showed more linear trajectories than groups moving north, indicating the beginning of their migration back to the feeding grounds. Energy conserving strategies and social context affect the movements of humpback whales in Serra Grande, resulting in the observed patterns of the reoccupation of available and suitable habitat north of Abrolhos. Thereby, special attention should be given managing activities with the potential to disturb or displace whales using the region to calve and breed.

Effects of temperature and loads on hardness and surface failure modes of cemented carbide

2020 ◽  
pp. 095440622095251
Author(s):  
Ben Wang ◽  
Tianxu Hao ◽  
Quanwei Yang ◽  
Minghai Wang ◽  
Yaohui Zheng
Keyword(s):  
Failure Modes ◽  
Indentation Test ◽  
Surface Damage ◽  
Mean Free Path ◽  
Cemented Carbide ◽  
Surface Failure ◽  
Binding Phase ◽  
Surface Damages ◽  
The Mean ◽  
Effects Of Temperature

Cemented carbide is a common cutting material with a hardness that significantly affects its usability. A Vickers indentation test was performed to analyse changes in the hardness of cemented carbide cutters with temperature and loads to understand its variation law. Moreover, indentation-induced surface damage was observed, and its elements were analysed. Crack distributions on the indentation surface were detected and analysed through an etching method. The results demonstrate that the hardness of cemented carbide decreases with greater temperatures and loads. At room temperature, the hardness of cemented carbide decreased from 1321 to 996 MPa when the loads increased from 300 to 800 N. When the external load was fixed at 500 N, the hardness of the cemented carbide decreased from 1113 to 939 MPa as the temperature increased from 25 to 350 °C. Moreover, the density of the indentation-induced surface damages increased with a reduction of the Vickers hardness. In addition, the mean free path of the binding phase for the cemented carbide with large grain sizes was relatively high. Therefore, it is difficult to generate diagonal cracks under large loads and high temperatures, which are beneficial to prevent cutter flaking.

Effects of temperature on the steady-state kinetics and measurement of aspartate aminotransferases.

1981 ◽  
Vol 27 (2) ◽  
pp. 213-219 ◽  
Author(s):  
R Rej ◽  
R E Vanderlinde
Keyword(s):  
Steady State ◽  
Enthalpy Change ◽  
Frequency Distributions ◽  
Similar Activity ◽  
Steady State Kinetics ◽  
Human Sera ◽  
Activity Temperature ◽  
Michaelis Constants ◽  
Effects Of Temperature ◽  
Kinetics Of

Abstract We examined the effects of temperature on the activity and steady-state kinetics of aspartate aminotransferase (EC 2.6.1.1), using purified human soluble (s-AspAT) and mitochondrial (m-AspAT) isoenzymes, human serum, and porcine s-AspAT. All enzymes obeyed similar linear Arrhenius relationships over the range 20-40 degrees C. Apparent energies of activation (52.3 kJ.mol-1) and ratios of activity between 30 and 37 degrees C (0.626) were identical for the human s- and m-AspAT. This ratio was 0.623 (SEM 0.004) for human sera; deviation from the predicted ratio by individual sera was within analytical error. Similar activity/temperature relationships were observed for porcine s-AspAT. The use of factors to convert AspAT activities at 30 and 37 degrees C influenced neither precision of measurement of frequency distributions of results. The apparent Michaelis constants for the human isoenzymes increased with temperature. The least-influenced Km was for 2-oxoglutarate and s-AspAT: K2-oxoglutarate was 0.24 mmol.L-1 at 25 degrees C and 0.29 mmol.L-1 at 37 degrees C; apparent enthalpy change for substrate binding (delta HS) was 12.1 kJ.mol-1. The largest variation was for 2-oxoglutarate and m-AspAT: K2-oxoglutarate was 0.46 mmol.L-1 at 25 degrees C and 1.02 mmol.L-1 at 37 degrees C; delta HS was 50.8 kJ.mol-1. Incubation of the human isoenzymes with substrate mixture (without 2-oxoglutarate) at 23 and 37 degrees C did not affect activity during 60 min if tris(hydroxymethyl)aminomethane buffer was used. When the isoenzymes were diluted to 10 nmol-L-1 (about 200 U.L-1) in buffer alone and incubated at 50 degrees C, m-AspAT activity was decreased by 20% after 120 min; the cytoplasmic enzyme was unaffected.

Caractéristiques de la coquille des oeufs chez la souche hybride (ovipare × vivipare) du lézard Lacerta vivipara

1992 ◽  
Vol 70 (11) ◽  
pp. 2242-2246 ◽  
Author(s):  
Benoît Heulin ◽  
Maria Jesus Arrayago ◽  
Antonio Bea ◽  
Florentino Brana
Keyword(s):  
Outer Surface ◽  
Experimental Studies ◽  
Dry Mass ◽  
Eggshell Membrane ◽  
Hybrid Strain ◽  
The Mean ◽  
Lacerta Vivipara

The lizard Lacerta vivipara has both oviparous and viviparous populations. Experimental crossbreedings (oviparous strain × viviparous strain) in the laboratory have previously allowed us to obtain a hybrid strain. Hybrids have also laid eggs in the laboratory. The aim of the present study was to determine the eggshell characteristics of the hybrid and to compare them with the characteristics previously studied in the oviparous and viviparous strains. The mean thickness of the eggshell is 21 μm for the hybrid, 40 μm for oviparous eggshell, and 9 μm for the viviparous eggshell membrane. Mean dry mass of the eggshell is 3 mg for hybrids, 5 mg for the oviparous strain, and 0.6 mg for the viviparous strain. Ash mass of the eggshell is 0.79 mg for hybrids, 1.05 mg for the oviparous strain, and 0.22 mg for the viviparous strain. Fibrils were observed in both oviparous and hybrids' eggshells and in the viviparous eggshell membrane. The outer surface of the hybrids' eggs presents both places with a calcareous layer (61%) and places where fibrils are not covered with a calcareous layer (39%). These incompletely calcified eggshells are intermediate between the oviparous eggshells (complete calcareous layer) and the regressed eggshell membrane (fibrils with minor traces of calcite) observed during the gestation of the viviparous lizards. This situation is of considerable interest for further experimental studies dealing with physiological and genetic aspects of the evolution of viviparity.

scholarly journals Influence of Dew Period and Temperature on Foliar Infection of Greenhouse-Grown Tomato by Colletotrichum coccodes

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 639-641 ◽  
Author(s):  
J. M. Byrne ◽  
M. K. Hausbeck ◽  
C. Meloche ◽  
A. M. Jarosz
Keyword(s):  
Leaf Disk ◽  
Leaf Wetness ◽  
Colletotrichum Coccodes ◽  
Leaf Position ◽  
Leaf Wetness Duration ◽  
The Mean ◽  
Effects Of Temperature ◽  
Leaf Disks

Effects of temperature, duration of leaf wetness, and leaf position on foliar infection of greenhouse-grown tomato (cv. Bonnie Best) by Colletotrichum coccodes were determined by inoculating plants with C. coccodes (5.0 × 105 conidia per ml) and keeping them in a dew chamber for 0, 4, 8, 12, 16, 20, or 24 h of wetting at 15, 20, or 25°C. One week after inoculation, leaf disks were placed on the surface of an amended medium on which colonies of C. coccodes were compact and easily identified, and severity of infection was quantified after 4, 6, and 8 days. There was no infection of plants incubated at 15°C, while plants kept at 20 or 25°C had increasing numbers of colonies when leaf wetness duration was extended beyond 12 and 8 h, respectively. Leaf position had a significant effect, with leaves tending to increase in susceptibility as they age. After 24 h of leaf wetness at 25°C, the mean number of colonies per leaf disk from top, middle, and bottom leaves was 23.8, 29.0, and 34.0, respectively.

scholarly journals Effects of temperature on the replication of chromosomal DNA of Xenopus laevis cells

1983 ◽  
Vol 59 (1) ◽  
pp. 1-12
Author(s):  
A.A. Al-Saleh
Keyword(s):  
Tissue Culture ◽  
Dna Replication ◽  
Xenopus Laevis ◽  
Replication Forks ◽  
Chromosomal Dna ◽  
The Mean ◽  
Effects Of Temperature

DNA fibre autoradiography has been used to study the effects of temperature on the replication of chromosomal DNA of Xenopus laevis cells in tissue culture at 18, 23 and 28 degrees C. Pulse/stepdown labelling shows that the DNA replicates bidirectionally. Origin-to-origin distances (initiation intervals) vary, but the range of and the mean initiation intervals at all three temperatures are much the same. The mean interval between initiation points is of the order of 60 to 66 microns. Staggering of initiation is evident at all three temperatures. Evidence against the existence of replication termini is provided. The rates of progress of DNA replication forks are 6 microns/h at 18 degrees C, 10 microns/h at 23 degrees C and 16 microns/h at 28 degrees C.

Effects of temperature and magnetic field on the ground state binding energy of the strong coupling magneto-polaron in an RbCl asymmetrical semi-exponential quantum well

2019 ◽  
Vol 33 (21) ◽  
pp. 1950239 ◽  
Author(s):  
Xiu-Qing Wang ◽  
Ying-Jie Chen ◽  
Jing-Lin Xiao
Keyword(s):  
Magnetic Field ◽  
Binding Energy ◽  
Quantum Well ◽  
Strong Coupling ◽  
Ground State ◽  
Unitary Transformation ◽  
Great Influence ◽  
Ground State Binding Energy ◽  
The Mean ◽  
Effects Of Temperature

The ground state binding energy (E[Formula: see text]) and the mean number of LO phonons (N) of the strong-coupling magneto-polaron (SCMP) in an asymmetrical semi-exponential quantum well (ASEQW) are studied theoretically. Temperature (T) effects on E[Formula: see text] and N are acquired with the quantum statistics theory (QST). By using the Lee-Low-Pines unitary transformation (LLPUT) and linear combination operation method (LCOM), the variations of E[Formula: see text] and N with T and [Formula: see text] of magnetic field are discussed. The investigated results indicate that both T and [Formula: see text] have great influence on E[Formula: see text] and N of LO phonons.

scholarly journals Temperature and vapour-trajectory controls on the stable-isotope signal in Canadian Rocky Mountain snowpacks

2009 ◽  
Vol 55 (191) ◽  
pp. 485-498 ◽  
Author(s):  
K.E. Sinclair ◽  
S.J. Marshall
Keyword(s):  
Rocky Mountain ◽  
Water Isotopes ◽  
Canadian Rocky Mountains ◽  
Deuterium Excess ◽  
Stable Water Isotopes ◽  
Air Mass ◽  
Trajectory Classification ◽  
The Mean ◽  
Effects Of Temperature ◽  
Using Data

AbstractThe effects of temperature and seasonal air-mass trajectories on stable water isotopes in alpine snowpacks are investigated using meteorological and snow-pit data at two alpine field sites in the Canadian Rocky Mountains: Haig Glacier, Alberta, and Opabin Glacier, British Columbia. Snow pits were sampled through three accumulation seasons (October–June, 2004/05, 2005/06 and 2006/07) for δ18O, δD, temperature and density. The isotopic characteristics of precipitation over these time periods, including the local meteoric waterline and average δ18O, δD and deuterium excess, were defined using this dataset. Individual snowfall events over the three seasons were identified in the accumulation records from both sites and then fit to snow-pit stratigraphies to determine their mean isotopic characteristics. A trajectory classification was produced for all events, and the key meteorological characteristics of each trajectory class were investigated using data from alpine field sites and a suite of meteorological records from the region. An analysis of the relative influences of temperature and air-mass trajectory on snow isotope ratios reveals some separation in mean δ18O between storm classes. However, the separation appears to be driven primarily by the mean temperature of each class rather then being a direct effect of vapour pathway.

Effects of temperature and host-plant on regulation of glasshouse mealybug (Hemiptera: Pseudococcidae) populations by introduced parasitoids (Hymenoptera: Encyrtidae)

1988 ◽  
Vol 78 (1) ◽  
pp. 135-142 ◽  
Author(s):  
C. C. D. Tingle ◽  
M. J. W. Copland
Keyword(s):  
Host Plant ◽  
Population Regulation ◽  
Ornamental Plants ◽  
Sampling Period ◽  
Planococcus Citri ◽  
Pest Population ◽  
Percentage Parasitism ◽  
The Mean ◽  
Effects Of Temperature ◽  
Leptomastidea Abnormis

AbstractIntroduction of parasitoids gave improved biological control of Planococcus citri (Risso) in a large glasshouse stocked with a variety of ornamental plants, supplementing that achieved by the predator Cryptolaemus montrouzieri Mulsant. Following parasitoid release, there was evidence of pest population regulation on guava and coffee bushes with reduced and stabilized mealybug numbers and stable percentage parasitism. The mean temperature during one sampling period was significantly correlated with the percentage parasitism two months later, indicating that temperature has a major impact on parasitoid efficiency. Leptomastidea abnormis (Girault) was responsible for about 90% of the parasitism observed; the remainder was by Leptomastix dactylopii Howard. The effects of supplementary inoculative releases of Leptomastidea abnormis were variable, but resulted in increased percentage parasitism only when the number released contributed significantly to those already established. No evidence of pest population regulation was found on Aristolochia or Passiflora vines nor on potted Gesneriaceae plants of the genera Streptocarpus and Saintpaulia. Peak mealybug populations on these last plants coincided with periods of new growth, fruiting or flowering. Host-plant quality thus seems to be a major factor inducing mealybug outbreaks.

Dynamics of predation in Lacertidae: the relation between locomotor pattern and prey-capture probability in three contrasted species

1995 ◽  
Vol 16 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Roger Avery ◽  
Gianluca Tosini
Keyword(s):  
Prey Capture ◽  
Capture Probability ◽  
Potential Prey ◽  
Podarcis Muralis ◽  
Single Item ◽  
Burst Length ◽  
Energy Expenditures ◽  
Locomotor Pattern ◽  
The Mean ◽  
Lacerta Vivipara

AbstractThe probability that lizards would capture crickets declined with distance from the snout, at rates which were significantly more rapid in all directions in Lacerta vivipara than in Podarcis muralis or L. viridis, i.e. the former species responded to potential prey over a smaller area. Capture probabilities at any distance in front of or behind the snout were lower in P. muralis or L. viridis which were pausing during locomotion than in basking lizards, confirming previous results with L. vivipara. Using capture probabilities for pausing lizards to calculate the average time it would take to find a single item of prey (tf) in relation to the mean length of locomotor bursts, on the assumption that prey could only be detected while a lizard was pausing, showed that actual mean burst distance corresponded exactly with the burst distances which gave rise to minimum tf in L. vivipara. Mean locomotor burst distances in P. muralis and L. viridis were lower than the distances which gave minimum tf values. It is suggested that, in these species, the mean burst length has evolved as a compromise between minimising tf and avoiding the high overall energy expenditures which would result from long burst lengths.

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