EXTRA-HAREM PATERNITY IN THE WHITE-LINED BAT SACCOPTERYX BILINEATA (EMBALLONURIDAE)

Behaviour ◽  
1999 ◽  
Vol 136 (9) ◽  
pp. 1173-1185 ◽  
Author(s):  
Otto Von Helversen ◽  
Christian Voigt ◽  
Frieder Mayer ◽  
Gerald Heckel
Keyword(s):  
Reproductive Success ◽  
Female Choice ◽  
High Stability ◽  
Group Composition ◽  
High Potential ◽  
The Other ◽  
Spatial Proximity ◽  
Harem Size ◽  
Microsatellite Typing ◽  
Saccopteryx Bilineata

AbstractWe studied the paternity in a colony of the harem-polygynous white-lined bat Saccopteryx bilineata by microsatellite typing and compared the data with group composition and stability. Although we recorded a high stability for harem groups, neither spatial proximity of males to harem females nor harem ownership allowed us to predict the paternity of the next year's harem offspring. Eight out of 28 juveniles were fathered by holders of the harem in which they were born, while the other 20 represent Extra-Harem-Young (EHY). 50% of EHY were fathered by males from outside the colony and 50% by other harem holders or peripheral males of the colony. On average, reproductive success of harem holders (1.2 offspring/year) was higher compared with peripheral males (0.4 offspring/year). Harem size seemed not to influence reproductive success of harem holders. Although maintaining of a territory seems to be costly for a harem male, his ability to control the females of his harem may be restricted; instead female Saccopteryx bilineata appear to have a high potential for female choice.

Endo-D-galacturonanase immobilized by adsorption on porous polyethyleneterephthalate

1982 ◽  
Vol 47 (10) ◽  
pp. 2716-2723 ◽  
Author(s):  
Lubomíra Rexová-Benková ◽  
Jiřina Omelková ◽  
Vladimír Kubánek
Keyword(s):  
Ionic Strength ◽  
High Stability ◽  
Relative Activity ◽  
Operational Stability ◽  
The Other ◽  
Fixation Strength ◽  
Action Pattern ◽  
Salt Solutions ◽  
Buffer Solution ◽  
Degradation Degree

Endo-D-galacturonanase of Aspergillus sp. was irreversibly adsorbed on polyethyleneterephthalate in an acetate 0.1 mol l-1 buffer solution of pH 4.2. Immobilization of the enzyme resulted in lowering of its activity, the measure of which depended on the amount of the enzyme fixed on the carrier. The highest relative activity (42.4%) had the preparation containing 5.25 mg of the enzyme per 1 g of the carrier. The velocity and intensity of the sorption of the enzyme depended on the ionic strength of the medium, whilst pH, on the other hand, was of no influence. Endo-D-galacturonanase immobilized in a 0.1 mol l-1 buffer was characteristic a) of its fixation strength in salt solutions of various ionic strength and pH, in a 3 mol l-1 guanidine solution, and also in sodium pectate and pectin solutions, b) of its high stability during a long-lasting storage at 4 °C, c) of its operational stability. The immobilization led to a partial change of the action pattern onto the high-molecular substrate, manifested in lowering the decrease of viscosity to degradation degree ratio.

scholarly journals Involvement of loop 5 lysine residues and the N-terminal β-hairpin of the ribotoxin hirsutellin A on its insecticidal activity

2016 ◽  
Vol 397 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Miriam Olombrada ◽  
Lucía García-Ortega ◽  
Javier Lacadena ◽  
Mercedes Oñaderra ◽  
José G. Gavilanes ◽  
...  
Keyword(s):  
Active Sites ◽  
Structural Changes ◽  
The Other ◽  
Spatial Proximity ◽  
Ribonucleolytic Activity ◽  
The Family ◽  
Lysine Residues ◽  
Hirsutella Thompsonii ◽  
Close Spatial Proximity ◽  
High Degree

Abstract Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger, with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties. Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently, four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity, being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

On the Opacity of Aluminium Foil to Ions from a Flame

1906 ◽  
Vol 25 (2) ◽  
pp. 903-907
Author(s):  
George A. Carse
Keyword(s):  
High Potential ◽  
The Other ◽  
Metallic Plate ◽  
Aluminium Foil ◽  
Image Position

The apparatus used to show that aluminium was opaque to the ions from a flame consisted (see fig. 1) of a tube A, which wasfunnel-shaped at one end, the other end of which led to an enclosure B, one side of which (a b) was made of aluminium foil connected to earth, and on the other side there was an insulated metallic plate (c d), which could either be connected to earth or to a high potential battery. On the other side of the aluminium foil there was an electroscope in a closed case C. The electroscope was of the type used by C. T. R. Wilson in his experiments on the natural ionisation of air in closed vessels.

Makeraia gen. nov. (Hymenoptera, Bethylidae), a long-antennated Pristocerinae from Madagascar

2021 ◽  
Vol 28 (2) ◽  
Author(s):  
DANIELE MUGRABI ◽  
CELSO AZEVEDO
Keyword(s):  
High Potential ◽  
The Other ◽  
Whole Body

Here we describe the flat wasp genus Makeraia gen. nov., and its three species M. migueli sp. nov., M. clariceae sp. nov. and M. lacinia sp. nov. from Madagascar. The males of this genus are easily recognized among the other genera of Pristocerinae by having the antennae very long, about as long as the whole body, a condition unique in Bethylidae. Our findings emphasize the endemicity of the flat wasp fauna of Madagascar and its high potential of biodiversity.

scholarly journals Performance of polychaete assisted sand filters under contrasting nutrient loads in an integrated multi-trophic aquaculture (IMTA) system

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Jerónimo ◽  
Ana Isabel Lillebø ◽  
Andreia Santos ◽  
Javier Cremades ◽  
Ricardo Calado
Keyword(s):  
Organic Matter ◽  
Reproductive Success ◽  
Particulate Organic Matter ◽  
Marine Invertebrates ◽  
The Other ◽  
Nutrient Loads ◽  
Effluent Water ◽  
Lower Content ◽  
Hediste Diversicolor ◽  
Sand Filters

AbstractPolychaete assisted sand filters (PASFs) allow to combine a highly efficient retention of particulate organic matter (POM) present in aquaculture effluent water and turn otherwise wasted nutrients into valuable worm biomass, following an integrated multi-trophic aquaculture (IMTA) approach. This study evaluated the bioremediation and biomass production performances of three sets of PASFs stocked with ragworms (Hediste diversicolor) placed in three different locations of an open marine land-based IMTA system. The higher organic matter (OM) recorded in the substrate of the systems which received higher POM content (Raw and Df PASFs – filtered raw and screened by drum filter effluent, respectively) likely prompted a superior reproductive success of stocked polychaetes (final densities 2–7 times higher than initial stock; ≈1000–3000 ind. m−2). Bioremediation efficiencies of ≈70% of supplied POM (≈1.5–1.8 mg L−1) were reported in these systems. The PASFs with lower content of OM in the substrate (Df + Alg PASFs – filtered effluent previously screened by drum filter and macroalgae biofilter) differed significantly from the other two, with stocked polychaetes displaying a poorer reproductive success. The PASFs were naturally colonized with marine invertebrates, with the polychaetes Diopatra neapolitana, Terebella lapidaria and Sabella cf. pavonina being some of the species identified with potential for IMTA.

Female Choice and Male Courtship Behaviour in the Beaugregory Damselfish

Behaviour ◽  
2004 ◽  
Vol 141 (4) ◽  
pp. 391-405 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Reproductive Success ◽  
Female Choice ◽  
Individual Variation ◽  
Early Stage ◽  
Breeding Site ◽  
Male Courtship ◽  
Egg Survival ◽  
Mean Values ◽  
Breeding Sites ◽  
Experimental Group

AbstractDuring courtship in the beaugregory (Stegastes leucostictus), a coral reef fish, males turn the dorsal half of their bodies from dull brown to bright yellow, and perform a series of rapid dipping movements in front of females. To look for evidence that females select males on the basis of these characteristics, we provided males with artificial breeding sites in the field, measured their reproductive success, and videotaped courtship. Reproductive success was measured by monitoring both the number and size of egg clutches present in the breeding site that was defended by the male. Both unmanipulated and experimentally induced courtship events were videotaped in separate groups of 88 (of which 32 were videotaped courting females) and 30 males, respectively. Experimental induction of courtship was done by placing a female in a clear plastic cylinder 0.5 m away from the breeding site of a territorial male; each of the 30 males received 8 different female presentations, but never more than one a day, and with a different female every time. We compared (i) the cumulative amount of eggs and number of clutches with the amount of yellow colouration and dipping rate for individual males in both the observational and experimental groups, (ii) individual variation in percentage yellow and dipping rate (for the experimental group only) with reproductive success on the same day when courtship was videotaped, and (iii) egg survivorship (ratio of final to early stage eggs) with yellow colouration and dipping rate, to see if these characteristics indicate male parental ability. Individual variation in courtship characteristics was not correlated with reproductive success on that day. In contrast, however, mean values of percentage yellow and dip rate were correlated with both the number of clutches and amount of eggs, for both the observational and experimental group of males, indicating that females preferentially spawn with males that have the brightest yellow colouration and the highest dip rate. Percentage yellow colouration was correlated with egg survival in the unmanipulated males, but not in the experimental group, while dipping rate was not correlated with egg survival in either group. We argue here that female assessment of male courtship is part of a complex process of female choice, in which females either simultaneously or sequentially examine territorial, breeding site, and male characteristics, and thereby attempt to enhance the survivorship of their offspring.

C60 Framework Response to Halogen Addition: the Stable Isomers of C60Br2m

1994 ◽  
Vol 47 (1) ◽  
pp. 131 ◽  
Author(s):  
JB Peel ◽  
RG Rothwell
Keyword(s):  
Double Bond ◽  
Molecular Orbital ◽  
High Stability ◽  
Structural Information ◽  
Spectroscopic Characterization ◽  
The Other ◽  
Semiempirical Calculations ◽  
Elementary Model ◽  
Local Distortion

The isolation and spectroscopic characterization of halogenated fullerene-60 compounds has not advanced greatly during the 2 years of effort in this area. While the fully fluorinated C60F60 has been studied in some detail, other halogen addition processes have indicated chlorination up to C60Cl24 and bromination up to C60Br24. However, definitive structural information has to date only been provided for three compounds, namely C60Br6, C60Br6 and C60Br24. Iodine does not appear to form genuine addition compounds. In the work reported here semiempirical calculations using the AM1 approximation with the MOPAC molecular orbital program have been directed to comparing the possible stable isomers of the 1:1 addition compounds C60X2 for X = F, Cl and Br. The favoured isomers can be described as 1,2-additions (to a double bond at a hexagon-hexagon fusion) and 1,4-additions (to the terminal carbons of a butadiene moiety) with higher-energy isomers resulting from 1,6- and 1,8-additions. The other isomers represented by 1,3- 1,5- and 1,7-additions are only stable relative to dissociation in the case of the fluorine addition compounds. By contrast for Br2 addition only the 1,2- and 1,4-isomers are stable toward dissociation. The calculations show that, at and near the addition site carbons, X2 addition is adequately described in terms of local distortion of the C60 sphere. The elementary model of C60 as comprising formal single and double bonds is relevant since C60 behaves as a 'poly- alkene ', with sp3 carbons replacing sp2 carbons at the addition sites. This model offers an explanation for the unique structures observed for C60Br6 and C60Br24 which the AM1calculations show to be very stable toward dissociation. However, the experimental C60Br8 structure is found to be relatively less stable than another isomer. Also high-stability isomers of C60Br4, C60Br10, C60Br12 and C60Br18 are predicted.

Goodness of Dot Patterns and Completion Variability: Effects of Equidistance and Collinearity of Dots

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 253-253
Author(s):  
S Markovic
Keyword(s):  
High Stability ◽  
The Other ◽  
Pattern Completion ◽  
Visual Patterns ◽  
Other Hand ◽  
Dependent Variables ◽  
The One ◽  
Initial Pattern ◽  
Important Stimulus

Visual patterns that are initially poorly specified can be perceptually completed into different Gestalten (eg dot patterns can impose the perception of different figures). In the present study the following hypothesis is evaluated. If the goodness of initial patterns is high enough (high Prägnanz), then the completion of initial patterns will result in a single Gestalt (high stability of percept). On the other hand, if the goodness is low (low Prägnanz), the completion will result in several Gestalten (perceptual multistability). In experiment 1 subjects estimated the goodness of four sets of initial 8-dot patterns. The distance between the dots was systematically varied. In experiment 2 the variability of completion of the same initial stimuli was examined. Subjects were asked to choose from a given set of figures the one that was most strongly suggested by the exposed initial dot pattern. The entropy, as a measure of the completion variability, was derived from the proportions of the choices of figures. The correlation between goodness estimates (Prägnanz level) and entropy (completion multistability) was significant: the higher the goodness, the lower the multistability of initial pattern completion. The arrangement of dots was an important stimulus constraint of the dependent variables. Increasing the number of equidistant extents between dots increased multistability and decreased goodness. Collinearity of dots induced a decrease of multistability and an increase of goodness.

Standard Plate for Radar Absorbing Materials’ Measurement in 3 mm Band

2012 ◽  
Vol 490-495 ◽  
pp. 3414-3417
Author(s):  
Jing Cheng Zhao ◽  
Yu Zhang ◽  
Hai Lun Yan
Keyword(s):  
Measurement System ◽  
High Stability ◽  
The Other ◽  
High Permittivity ◽  
Absorbing Materials ◽  
Standard Plate ◽  
Reflecting Surface

This paper introduces a new standard reflecting plate’s manufacture, which is used to calibrate the measurement system for radar absorbing materials in 3 mm band. The new standard plate is designed and employed with two reflecting surface, one is a plane, the other one is curve, and metal with high permittivity. It has the nominal reflectivity of -15dB, -10dB, -5dB and has the advantages of high stability, easy manufacture and convenient usage

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