Experimental investigations of the evolutionary significance of sexually dimorphic nuptial colouration in Gasterosteus aculeatus (L.): the relationship between male colour and female behaviour

1990 ◽  
Vol 68 (3) ◽  
pp. 482-492 ◽  
Author(s):  
D. A. McLennan ◽  
J. D. McPhail
Keyword(s):  
Gasterosteus Aculeatus ◽  
Cladistic Analysis ◽  
Initial Response ◽  
Choice Test ◽  
Choice Situation ◽  
Evolutionary Significance ◽  
Experimental Investigations ◽  
Courtship Signal ◽  
Female Behaviour ◽  
High Level

Cladistic analysis of behavioural interactions during a series of female choice trials revealed three groups of reproductively unsuccessful males in a population of anadromous Gasterosteus aculeatus: inactive losers (losing male did not participate in choice test), active losers (losing male active during choice test), and fighting losers (subgroup of active losers defined by the observation that the female did not immediately follow the first male to approach her). The inactive losers group represents a "no choice" situation. In the remaining two groups, females responded preferentially to the most intensely coloured member of the competing male pair. This preferential response was strongest during the prechoice, captive presentation where the majority of females oriented head-up to, and tracked, the brighter red male. Once released, the female's initial response to the brighter courtship signal was overridden by the behavioural actions of the duller intensity male in 4 out of 12 trials. Although two of these males eventually lost the female to their rival, the remaining two individuals succeeded in spawning. Overall, 10 of 12 females spawned with the brighter red male. Given the brief breeding season and the advantage enjoyed by the most brightly coloured males in mate attraction, a high level of territorial intrusion is one way for an individual to attract a mate if he is surrounded by more intensely coloured neighbours.

Experimental investigations of the evolutionary significance of sexually dimorphic nuptial colouration in Gasterosteus aculeatus (L.): the relationship between male colour and male behaviour

1989 ◽  
Vol 67 (7) ◽  
pp. 1778-1782 ◽  
Author(s):  
D. A. McLennan ◽  
J. D. McPhail
Keyword(s):  
Gasterosteus Aculeatus ◽  
Evolutionary Significance ◽  
Experimental Investigations ◽  
Sexually Dimorphic ◽  
Colour Intensity ◽  
Central Section ◽  
Medium Intensity ◽  
Group A ◽  
The Relationship ◽  
Colour Signal

The intensities of red body and blue eye colour in dull (and possibly bright) males reliably signals their behavioural vigour. Males with medium intensity colouration signal that they are more vigorous than their dull conspecifics; however, there is no association between colour and behavioural intensity within this group. A truth in advertising mechanism is thus potentially very powerful at either end of the colour intensity spectrum but is less effective for fish whose colouration is in the central section of the spectrum. Males with medium intensity colouration may be more strongly influenced by stochastic factors such as previous experiences or colour relative to neighbours. The increased importance of personal history introduces a source of disorganization into the mating system that may oppose the directional force of truth in advertising and thereby increase the ambiguity of the male colour signal.

Experimental investigations of the evolutionary significance of sexually dimorphic nuptial colouration in Gasterosteus aculeatus (L.): temporal changes in the structure of the male mosaic signal

1989 ◽  
Vol 67 (7) ◽  
pp. 1767-1777 ◽  
Author(s):  
D. A. McLennan ◽  
J. D. McPhail
Keyword(s):  
Gasterosteus Aculeatus ◽  
Black Body ◽  
Evolutionary Significance ◽  
Experimental Investigations ◽  
Breeding Cycle ◽  
Sexually Dimorphic ◽  
Body Colour ◽  
Colour Intensity ◽  
Lateral Body ◽  
Blue Eyes

Although classically described as "red," the three-spined stickleback male's nuptial signal is a complex mosaic of at least three colours: blue eyes, black dorsal–lateral body, and red ventral–lateral body. Seven variables (intensity, hue, and distribution of red body colour; intensity and hue of blue eye colour; intensity and distribution of black body colour) were scored for 19 males across an entire breeding cycle. These variables interacted to produce four distinct male colour mosaic signals corresponding with the stage a male had reached in the breeding cycle. No single variable was sufficient for the delineation of all breeding stages: however, the distribution of red body colour reliably distinguished the courting male from nesting and parental males. Variability in signal intensity between courting males was greatest for the red component of the nuptial signal and both intra- and inter-male variability in the overall intensity of red was greatest during courtship. Based upon these results, future investigations of the role of intersexual selection in shaping the male nuptial signal in this species should offer females a choice between males differing in the intensity of red rather than the traditional "red" versus "nonred" dichotomy.

scholarly journals Energy-sparing adaptations in human pregnancy assessed by whole-body calorimetry

1989 ◽  
Vol 62 (1) ◽  
pp. 5-22 ◽  
Author(s):  
A. M. Prentice ◽  
G. R. Goldberg ◽  
H. L. Davies ◽  
P. R. Murgatroyd ◽  
W. Scott
Keyword(s):  
Energy Cost ◽  
Initial Energy ◽  
Whole Body ◽  
Evolutionary Significance ◽  
Energy Status ◽  
Voluntary Activity ◽  
Human Pregnancy ◽  
Significant Depression ◽  
Wide Variability ◽  
High Level

The hypothesis that the energy cost of human pregnancy can be minimized by energy-sparing metabolic adaptations was tested using serial 24 h whole-body calorimetry. Eight healthy, well-nourished women were studied prepregnant and at 6, 12, 18, 24, 30 and 36 weeks gestation. Basal metabolic rate (BMR) showed highly characteristic changes within each subject and large inter-individual differences (F 3.5, P < 0.01). Some subjects showed a highly significant depression of metabolism up to 24 weeks gestation in support of the initial hypothesis. At 36 weeks BMR ranged from +8.6 to +35.4% relative to the prepregnant baseline. This wide variability was not explained by differences in the amount of lean tissue gained. Women displaying the energy-sparing suppression of BMR tended to be thin, suggesting that changes in metabolism may be responsive to initial energy status (ΔBMR ν. prepregnant body fat: r 0.84, P < 0.005). Changes in 24 h energy expenditure closely paralleled changes in BMR (r 0.98, P < 0.001), since the energy cost of minor voluntary activity and thermogenesis remained very constant within each individual. Pregnancy decreased the net cost of weight-dependent and weight-independent standard exercises when expressed per kg body-weight: stepping – 10 (sd 2)%, P < 0.001 at 18–36 weeks, cycling - 26 (sd 7)%, P < 0.01 at 12–36 weeks. The average integrated maintenance costs of pregnancy matched previous group estimates from well-nourished women, but individual estimates ranged from - 16 to + 276 MJ (coefficient of variation 93%). This high level of variability has important implications for the prescription of incremental energy intakes during pregnancy. It may also have had evolutionary significance.

scholarly journals Olanzapine-high potency antipsychotic drug inducing significant weight gain: A case report

2008 ◽  
Vol 136 (5-6) ◽  
pp. 284-288 ◽  
Author(s):  
Nadja Maric ◽  
Dragana Josifovic-Kostic ◽  
Olivera Vukovic ◽  
Dubravka Britvic ◽  
Miroslava Jasovic-Gasic
Keyword(s):  
Weight Gain ◽  
Psychotic Disorders ◽  
Vascular Diseases ◽  
Initial Response ◽  
Young Female ◽  
The Body ◽  
Average Weight ◽  
Therapeutic Effects ◽  
Significant Weight Gain ◽  
High Level

INTRODUCTION Olanzapine is a second generation antipsychotic (SGA) with a high level of therapeutic effectiveness in schizophrenia and other psychotic disorders. Along with the positive therapeutic effects, an increase of the body weight frequently occurs. According to the literature, the average weight gain is about 6-7 kg during several months of treatment. This could be valued as a moderate weight increase. CASE OUTLINE This article presents a case of a young female with schizophrenia, without clinical improvement with several antipsychotics (clozapine, risperidone, haloperidol) and with the occurrence of significant neurological side effects. The treatment started with olanzapine (baseline) was associated with good initial response (PANSS reduction 20% in the first two weeks) and the improvement was maintained further on (PANSS reduction 50% after 16 weeks). Significant increase (20 kg, 40%) in weight appeared during the following 16 weeks (BMI at baseline 17.9 kg/m2; BMI 16 weeks later 25.1 kg/m2). CONCLUSION High effectiveness of olanzapine in schizophrenia symptoms reduction was accompanied by a significant weight gain. However, this drug leads to impaired glucoregulation, dyslipidaemia etc. It also increases the risk of diabetes and cardio-vascular diseases, i.e. the main causes of mortality in schizophrenia after a suicide. Therefore, clinicians are suggested to focus on possible predictors of weight gain during olanzapine therapy, and act accordingly in order to prevent serious health consequences.

An Experimental Investigation of the Flow in a 1½ Stage Axial Turbine With Regard to a High Level of Cooling-Air Injection

1999 ◽  
Author(s):  
U. Reinmöller ◽  
H. E. Gallus
Keyword(s):  
Film Cooling ◽  
Turbine Blades ◽  
Gas Injection ◽  
Leading Edge ◽  
Experimental Investigations ◽  
Flow Angle ◽  
Turbine Cooling ◽  
Flow Mixing ◽  
Reference Measurements ◽  
High Level

Experimental investigations of flow mixing due to film cooling of turbine blades have been performed. In a 1½-stage axial air turbine cooling gas (cool nitrogen down to −130 °C) was blown directly onto the leading edge of the first stator by special gas injector devices. In order to provide a database for the verification of numerical codes and to give an impression of the mixing process the gas has been injected at different radial positions. Furthermore the cooling massflow and cooling temperature were varied. The measuring data were obtained using pneumatic 5-hole probes with temperature sensors. The presented experimental data were simultaneous acquired in the planes behind both stators and the rotor. The results are compared and, discussed with reference measurements without cooling gas injection. It is shown that the effect of cooling gas injection is apparent in the wake of the first stator where it causes a small decrease in the pressure distribution as a result of increased flow mixing. Behind the first stator differences in the circumferentially averaged pitchwise flow angle due to the injected gas were not measured. Furthermore, temperature measurements clearly show the effect of the cooling gas injection in all planes. Even behind the second stator the different magnitudes of the temperature distribution are caused by the various injection of cooling gas.

Methodology in the Development Process of Large Gaseous Fuelled Engines

2003 ◽  
Author(s):  
Gerhard Kogler ◽  
Andreas Wimmer ◽  
Helmut Eichlseder ◽  
Eduard Schnessl ◽  
Hubert Winter
Keyword(s):  
Development Process ◽  
Thermal Power ◽  
Experimental Investigations ◽  
Block Type ◽  
Pyrolysis Gas ◽  
Simulation Tools ◽  
Power Stations ◽  
Thermal Power Stations ◽  
High Level ◽  
Fuel Consumption And Emissions

High demands are placed on large gaseous-fuelled engines regarding performance, fuel consumption and emissions. Because of the different applications of gaseous-fuelled engines (block-type thermal power stations, generation of electric power in a stand alone plant, etc.) and the use of different kinds of gases (natural gas, wood gas, pyrolysis gas, dump gas, etc.), the optimization process can be seen as a very complex task. Today engines have already reached a high level of development and further improvements can only be realized with very high expenditures. Experience has shown that a purely experimental approach is no longer sufficient and therefore the application of modern simulation tools is necessary. In this paper a combined development process is described consisting of simulation, experimental investigations on a single cylinder research engine and transfer on a full scale engine as an example for the optimization of a gas-purched prechamber concept.

Phylogeny of the clawed lobsters (Crustacea: Decapoda: Homarida)

Zootaxa ◽  
2006 ◽  
Vol 1109 (1) ◽  
pp. 1 ◽  
Author(s):  
SHANE T. AHYONG
Keyword(s):  
Phylogenetic Relationships ◽  
Phylogenetic Signal ◽  
Cladistic Analysis ◽  
Phylogenetic Studies ◽  
High Level ◽  
Jackknife Support

The generic and familial structure of the clawed lobsters, Homarida, was studied by cladistic analysis. Previous phylogenetic studies of the clawed lobster genera have focussed on the putative nephropoid families: Nephropidae, Thaumastochelidae, and Chilenophoberidae. Recent high-level studies of decapod phylogeny, however, show that in addition to Nephropidae and Thaumastochelidae (both Nephropoidea), the Enoplometopidae (Enoplometopoidea) are ingroup homaridans. Conversely, the homaridan placement of Chilenophoberidae has been questioned, instead possibly having astacidan affinities. This study, building on previous analyses, incorporates additional taxa and data to examine phylogenetic relationships of the genera and families. Analyses were conducted including both extant and extinct taxa (analysis A), and with extant taxa only (analysis B). The resulting topologies from analyses A & B were largely compatible indicating that the phylogenetic signal among homaridan genera was not significantly impacted by fossil taxa. Results support recognition of Nephropoidea, comprising Thaumastochelidae and Nephropidae, and Enoplometopoidea, comprising Enoplometopidae and Uncinidae. Affinities of Chilenophoberidae were found to lie with Astacida rather than Homarida, albeit with weak jackknife support. Thaumastochelidae is strongly supported as monophyletic, with two extant genera and the extinct Oncopareia. Present data, however, are equivocal about an independently monophyletic Nephropidae.

Habituation of a Predatory Response in the Stickleback (Gasterosteus Aculeatus)

Behaviour ◽  
1995 ◽  
Vol 132 (15-16) ◽  
pp. 1255-1266 ◽  
Author(s):  
Harman V.S. Peeke
Keyword(s):  
Gasterosteus Aculeatus ◽  
Glass Tube ◽  
Initial Response ◽  
Functional Requirements ◽  
Territorial Aggression ◽  
Predatory Response ◽  
Gravid Females ◽  
Response Habituation ◽  
Incremental Process ◽  
Density Results

AbstractSticklebacks presented with a clear glass tube filled with live brine shrimp will initially attempt to capture them; however, the response wanes within minutes. In the case of females, the rate of initial response is enhanced and the rate of waning is influenced by the state of the female (gravid females are more responsive) and by the density of the prey (greater density results in greater responsiveness). The predatory-response habituation differs from habituation of territorial aggression and courtship in that the pre-decremental, incremental process is absent. In common with habituation of territorial aggression but not with courtship, there is little short-term recovery of the response. The differences are consistent with different functional requirements for an experience-based inhibitory mechanism involved in the modulation of stickleback behaviour.

scholarly journals Competitive adsorption of plasma proteins on polysaccharide-modified silicon surfaces

2004 ◽  
Vol 845 ◽  
Author(s):  
Michela Ombelli ◽  
Lauren B. Costello ◽  
Qing Cheng Meng ◽  
Russell J. Composto ◽  
David M. Eckmann
Keyword(s):  
Protein Adsorption ◽  
Research Effort ◽  
Sodium Hyaluronate ◽  
Initial Response ◽  
Silicon Surfaces ◽  
Blood Proteins ◽  
Artificial Surface ◽  
Main Components ◽  
High Level ◽  
Nonspecific Protein Adsorption

ABSTRACTThe initial response of blood exposed to an artificial surface is the adsorption of blood proteins that triggers a number of biological reactions such as inflammation and blood coagulation. Competitive protein adsorption plays a key role in the hemocompatibility of the surface. The synthesis of nonfouling surfaces is therefore one of the major prerequisites for devices for biomedical applications. Polysaccharides are the main components of the endothelial cell glycocalyx and have the ability to reduce nonspecific protein adsorption and cell adhesion and, therefore, are generally coupled with a wide variety of surfaces to improve their biocompatibility. We have developed a procedure for covalently binding dextran and sodium hyaluronate (HA) on silicon wafers and we have been able to achieve a high level of control over the surface properties of the coatings. In the present research effort we focus on a detailed investigation of competitive bovine serum albumin (BSA) and bovine fibrinogen (Fg) adsorption on dextran- and HA-modified silicon surfaces. Polysaccharide based biomimetic layers preferentially adsorb BSA and, in general, strongly suppress protein adsorption with respect to bare silicon and APTES-activated silicon surfaces used as control.

Investigation of Blade and Disc Vibrations on the Upgraded Power Turbine for the THM 1304 Gas Turbine

2004 ◽  
Author(s):  
D. Frank ◽  
A. Kleinefeldt ◽  
U. Orth ◽  
W. Cline
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Turbine Blades ◽  
Mode Shapes ◽  
Experimental Investigations ◽  
Numerical Predictions ◽  
Power Turbine ◽  
Temperature Capability ◽  
Blade System ◽  
High Level

As part of an ongoing uprating and upgrading program of the THM 1304 gas turbine directed towards increasing power output and efficiency as well as further improving the high level of availability, major design modifications were made on the power turbine (PT). New blades and vanes were designed for increased aerodynamic efficiency, improved high temperature capability, higher power output and higher nominal operating speed. This report presents the analytical and experimental investigations made on the vibration modes and frequencies of blades with pre-loaded interlocking tip shrouds. One focus is upon observed families of mode shapes at different nodal diameters. A comparison of finite-element results with test data shows how good predictions are in the case of coupled blade vibrations. The value of testing the vibration behavior of power turbine blades in the actual machine, over the complete speed range, becomes evident as an important addition to the numerical predictions and laboratory tests. Another focus is on the method of testing, including the telemetry system used and the problem of optimum placement of strain gages on the blades. The selected strain gage positions are crucial to the value and meaningfulness of the test results. The observed strain vibration amplitudes were compared with high-cycle-fatigue (HCF) data available for the blade material. It was shown that measured amplitudes were significantly below allowable levels over the complete range of operating power and speed. The analytical and experimental methods employed to determine blade mode shapes and frequencies for a blade system with pre-loaded tip shrouds are presented in detail.

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