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1.
J Hered ; 95(2): 119-26, 2004.
Article in English | MEDLINE | ID: mdl-15073227

ABSTRACT

Eight microsatellite loci were used to investigate the genetic structure of the giant honeybee (Apis dorsata) population in northeast India. This species migrates seasonally between summer and winter nesting sites, and queens appear to return to their previously occupied site. Furthermore, there is a strong tendency for colonies of this species to aggregate at perennially utilized nesting sites that may be shared by more than 150 colonies. These behavioral features suggest that colonies within aggregations should be more related than random colonies, but that the long-distance migration could act to minimize genetic differentiation both between geographical areas and within aggregations. Our genetic study supports these conjectures arising from natural history. A. dorsata aggregations are comprised of colonies that share more alleles than expected by chance. Although queens heading neighboring colonies are not close relatives, fixation indices show significant genetic differentiation among aggregation sites. However, there appears to be sufficient gene flow among aggregations to prevent high degrees of relatedness developing between colonies within aggregations. The results also suggest that there is significant population structuring between geographical regions, although the level of structuring caused by aggregation exceeds the differentiation attributable to geographic region.


Subject(s)
Bees/genetics , Genetic Variation , Genetics, Population , Animal Migration , Animals , DNA Primers , Electrophoresis, Polyacrylamide Gel , Gene Frequency , Geography , Homing Behavior , India , Linkage Disequilibrium , Microsatellite Repeats/genetics , Species Specificity
2.
Naturwissenschaften ; 89(7): 326-8, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12216866

ABSTRACT

We report the results of a simple experiment to determine whether honeybees feed their small hive beetle nest parasites. Honeybees incarcerate the beetles in cells constructed of plant resins and continually guard them. The longevity of incarcerated beetles greatly exceeds their metabolic reserves. We show that survival of small hive beetles derives from behavioural mimicry by which the beetles induce the bees to feed them trophallactically. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at htpp://dx.doi.org/10.1007/s00114-002-0326-y.


Subject(s)
Bees/physiology , Coleoptera/physiology , Feeding Behavior/physiology , Adaptation, Physiological , Animals , Behavior, Animal
3.
Parasitology ; 121 Pt 5: 483-92, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11128799

ABSTRACT

Light and transmission electron microscopy revealed pericytes of brain capillaries of moles (Talpa europaea L., 1758) as parasitized intracellularly. These host cells were enlarged and of globular or ellipsoid shape, and incorporated a cell-within-cell sequence of primary, secondary and, rarely found, tertiary developmental stages of an eukaryotic organism. Other stages like spores were not discovered either in brain or in other organs. Due to the vertebrate host, and the parasitic cells showing the enveloped state this parasite can be classified as belonging to the Myxozoa rather than Paramyxea. Since spores, which would allow an exact identification of the parasite, could not be detected and mammals are very unusual hosts for Myxozoa, the parasite was designated a myxozoan-like organism.


Subject(s)
Brain/parasitology , Eukaryota/physiology , Moles/parasitology , Protozoan Infections/pathology , Animals , Azure Stains/chemistry , Brain/pathology , Capillaries/parasitology , Capillaries/pathology , Eukaryota/classification , Eukaryota/ultrastructure , Image Processing, Computer-Assisted , Microscopy, Electron/veterinary
4.
Nature ; 406(6795): 475, 2000 Aug 03.
Article in English | MEDLINE | ID: mdl-10952300
5.
Behav Res Methods Instrum Comput ; 32(1): 157-68, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10758673

ABSTRACT

Viscovery SOMine is a software tool for advanced analysis and monitoring of numerical data sets. It was developed for professional use in business, industry, and science and to support dependency analysis, deviation detection, unsupervised clustering, nonlinear regression, data association, pattern recognition, and animated monitoring. Based on the concept of self-organizing maps (SOMs), it employs a robust variant of unsupervised neural networks--namely, Kohonen's Batch-SOM, which is further enhanced with a new scaling technique for speeding up the learning process. This tool provides a powerful means by which to analyze complex data sets without prior statistical knowledge. The data representation contained in the trained SOM is systematically converted to be used in a spectrum of visualization techniques, such as evaluating dependencies between components, investigating geometric properties of the data distribution, searching for clusters, or monitoring new data. We have used this software tool to analyze and visualize multiple influences of the ocellar system on free-flight behavior in giant honeybees. Occlusion of ocelli will affect orienting reactivities in relation to flight target, level of disturbance, and position of the bee in the flight chamber; it will induce phototaxis and make orienting imprecise and dependent on motivational settings. Ocelli permit the adjustment of orienting strategies to environmental demands by enforcing abilities such as centering or flight kinetics and by providing independent control of posture and flight course.


Subject(s)
Electronic Data Processing , Flight, Animal/physiology , Nerve Net/physiology , Software , Vision, Ocular/physiology , Animals , Bees/physiology , Humans
6.
Vet Hum Toxicol ; 36(1): 56-9, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8154105

ABSTRACT

We studied the influence of specially prepared highly diluted thyroxine on the spontaneous tendency of juvenile frogs, which were at the end of thyroxine-controlled metamorphosis, to leave the water and climb onto land. The test dilution with a thyroxine concentration beyond Avogadro's value (dilution thyroxine D30) and the reference (dilution water D30) were prepared according to directions from the literature on homeopathy. A few drops of these solutions were added to tap water of basins containing the frogs. The frogs' climbing activities were monitored immediately after adding the solutions. The hypothesis derived from a preliminary study was that there is less climbing activity in frogs treated with dilution thyroxine D30 than in a reference group. This hypothesis was proven. Climbing activity diminished under the influence of dilution thyroxine D30, with statistical significance both in comparison to the effect of the analogously prepared solvent (dilution water D30) as well as in comparison to control observations before the start of treatment. When in a later step of observation the dilution water D30-control group was treated with dilution thyroxine D30, the diminishing effect on activity also occurred.


Subject(s)
Motor Activity/drug effects , Rana temporaria/physiology , Thyroxine/pharmacology , Animals , Depression, Chemical , Temperature
7.
Br. homoeopath. j ; 80(4): 194-200, out. 1991. ilus, tab
Article in English | HomeoIndex Homeopathy | ID: hom-1615

ABSTRACT

The experiments investigate the influence of extremely dilute thyroxine (T4) in special "homoeopathic" preparation (dilution T4.30x) on the spontaneous tendency of juvenile frogs to leave the water and climb on land. Climbing activity was suppressed by dilution T4.30x, with statistical significance both in comparison to the effect of the "potentized" preparation of the solvent (dilution H2O.30x) as well as in comparison to the control observations before the start of the treatment. Finally, in the search for optimal treatment duration, it was shown that exposure to the dilutions for even a few minutes sufficed to cause significant effects


Subject(s)
Animals , Thyroxine/pharmacology , Basic Homeopathic Research , Rana temporaria , Austria
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