Two viruses were isolated from honey bees. When fed to, sprayed on, or injected into healthy bees either virus made the bees become trembly within a few days, but whereas bees infected with one virus died quickly (acute “paralysis”), bees infected with the other survived for several days after first showing symptoms (chronic “paralysis”). Purified preparations of acute bee paralysis virus (ABPV) contained isometric particles about 28 mμ in diameter, whereas those of chronic bee paralysis virus (CBPV) contained particles of irregular shape about 27 × 45 mμ. Both viruses occurred in apparently healthy bees, but only CBPV particles were numerous in diseased bees from colonies naturally affected with the disease called “bee paralysis.” On inoculation to healthy bees the symptoms caused by CBPV resembled those of the naturally occurring disease more than did those caused by ABPV.
The experiments described lead to the conclusion that this saliva comes from the labial glands, and not from the mandibular glands, as has sometimes been supposed. The mandibular glands have no mechanical connection with chewing, and their outlets are not on the mandibles.
The physical and chemical properties have been determined on 60 samples of crude beeswax, obtained for the most part from beekeepers in California and other Western States, and these properties have been compared with those of freshly secreted scale wax and also with the properties of many of the same crude waxes after they had been decolorized by various processes.
For freshly secreted beeswax the properties are nearly constant, but with changes in the quantity and kind of contaminating impurities some or all of these properties change. The physical and chemical properties of the impurities, and not of the waxes as a whole, must therefore be used as the basis for classifying crude beeswaxes.
The impurities in crude beeswax consist of honey, suspended particles, or dissolved substances, and may or may not be colored. The soluble colored materials are attributable to substances extracted from pollens, to propolis, and to substances produced by contact of the wax with metals. Darkening of crude wax by contact with iron or oxides of iron is very common.
The crude waxes that were highly contaminated with propolis showed higher densities, indices of refraction, acid numbers, and iodine numbers than those containing little propolis but appreciable quantities of other soluble contaminants. Samples high in propolis could not be decolorized by sun bleaching or adsorption...
The curve of growth of the queen bee larva is exponential during 4 days from hatching of the egg, the weight increasing by a factor of 5 each 24 hours. The weight of the worker larva deviates from this curve and after two days increases at a decreasing rate. The worker matures later than does the queen larva.
Volumes both of the cells of the fat body and of their nuclei increase at a decreasing rate. The cytoplasm increases much more rapidly than does the nucleus, from about one-half the cell volume at hatching to nine-tenths at larval maturity. The nuclear changes initiated at beginning of metamorphosis precede the cessation of feeding, and in the queen larva nearly coincide with the sealing over of the wax ceIl, after which the larva continues to feed during cocoon spinning on material previously deposited in the cell.
No mitoses occur in the fat body cells after hatching, though nuclear content of chromatin material increases with increase of nuclear volume, presumably by polyteny. During pupation the cell cytoplasm disintegrates but the stripped nuclei persist for some time with deeply staining granules and nuclear membrane.
The fat body tissue at larval maturity constitutes approximately 60% of body weight, and 80% of the formed tissue after drainage of blood. The larval DNA content increases at a higher rate than does the nuclear volume. Thymidine-C14 uptake in vitro...
Honigbienenvölker wurden im Winter aus ihren Stöcken genommen und in galvanisierten Eisenbehältern (Tanks) Temperaturen zwischen 20 und —39° C ausgesetzt. Das Kohlendioxyd der aus den Behältern abgesogenen Luft wurde absorbiert und gewogen. Die CO2-Produktion sank, wenn die Temperatur von 20 auf 10° erniedrigt wurde und stieg bei niederen Temperaturen wieder an. Diese Veränderungen verliefen in umgekehrter Richtung, wenn die Temperatur erhöht wurde.
Four methods of confining colonies of honeybees for up to 12 hours (with and whitout water) were tested : (1) black or white-painted polythene sheeting, (2) wet or dry burlap (jute sacking), (3) entrance screen, (4) chipped ice over the hive entrance. Colony temperatures and reactions were nearest to normal when wet burlap or ice was used. In 1960, when external air temperatures reached about 36°C, all colonies beneath plastic were killed, as well as one with an entrance screen.
The reported changes in foraging behaviour of honeybees after carbon dioxide anaesthesia (Ribbands, 1950) led to somewhat similar tests being made in this laboratory. The treatments were extended to include variously aged instars. Observations were also made on the effects of carbon dioxide narcosis on colony behaviour and upon the life expectancy of newly emerged bees
La malnutrition est identifiée comme l’un des facteurs potentiellement responsables des mortalités élevées de colonies d’abeilles des dernières années au Québec. Pour contrer cela, les apiculteurs donnent des suppléments de pollen à leurs colonies, mais les impacts d’une telle pratique à diverses périodes sont méconnus. Les effets de la disponibilité du pollen sur le développement de colonies d’abeilles ont été mesurés pendant 3 différentes périodes : au printemps, durant la pollinisation de la canneberge et à la fin de l’été. À chacune des périodes correspondait une expérience distincte utilisant 40 colonies. Pour chaque expérience, des conditions d’abondance de supplément de pollen et de restriction de pollen naturel étaient créées chez les colonies pendant un mois selon un plan d’expérience factorielle 2x2. L’élevage du couvain et la récolte de miel ont été mesurés jusqu’à la fin de l’été (début de l’été suivant pour l’expérience de fin d’été). Au printemps, les colonies restreintes en pollen naturel ont élevé 18% moins de couvain (p<0.05) pendant la période de restriction et 11% de moins à la fin de l’été alors que l’utilisation du supplément n’a eu aucun effet (p>0.05). Les colonies supplémentées durant la pollinisation des canneberges ont élevé moins de couvain (p<0.05) à la fin de l’été. Pour l’expérience de fin d’été...
This paper presents a novel architecture,
MobiSplit, to manage mobility in future IP based networks.
The proposed architecture separates mobility management in
two levels, local and global, that are managed in completely
independent ways. The paper describes the flexibility
advantages that this architecture brings to operators, and how
it is appropriate for the current trend to multiple and very
different access providers and operators. Heterogeneity,
support for seamless handovers and multihoming, and
scalability issues are analyzed in the paper.; First ACM/IEEE International Workshop on Mobility in the Evolving Internet Architecture. Session: Architectural issues. San Francisco, California, Dec. 01 2006
Fonte: École Doctorale « Territoires, Temps, Sociétés et Développement »Publicador: École Doctorale « Territoires, Temps, Sociétés et Développement »
Tipo: Artigo de Revista Científica
Publicado em //2007FRA
Relevância na Pesquisa
En hébreu, le mot « abeille » dérive de la racine « dbr » qui signifie « parole ». Cela indique la mission de cet animal : révéler la parole divine, la Vérité. Dans quelques communautés juives, avant d’envoyer les enfants apprendre l’alphabet, les mères confectionnent des gâteaux au miel en forme de lettres afin que les enfants aient un avant-goût de la douceur de la connaissance. L’abeille a une importance symbolique non négligeable depuis la nuit des temps en tant que manifestation du pouvoir divin. Sans doute la transmutation de la matière du pollen des fleurs en miel, ainsi que l’organisation au sein d’une ruche, ont suscité l’intérêt de l’homme pour cet animal. Sobriété, abstinence de viande et de rapports sexuels, labeur, propreté, silence, sens du bien commun, discipline et sociabilité sont quelques caractères attribués à cet insecte. Par conséquent, il n’est pas difficile de comprendre pourquoi l’abeille fut la source d’inspiration d’un idéal humain étroitement lié aux vierges, aux épouses ainsi qu’aux saintes. De plus, le miel, seule source de sucre jusqu’au Moyen Âge, semble correspondre au nectar divin par sa couleur, sa texture et son goût. L’objectif de cet article est d’illustrer le rapport entre l’homme et l’animal en soulignant le fait que réalité et imaginaire sont intrinsèquement liés. En effet...
An account is given of the salivation process in Apis mellifera. The mechanisms by which the hairs of the tongue are erected and the ligula retracted, and the action of the salivary pump, are described, and their effect on the discharge of saliva and intake of food are discussed.
Acute bee paralysis virus (ABPV) occurs commonly in adult honey bees (Apis mellifera Linnaeus) in Britain. The amount of the virus in different bees differs, as does the proportion of infected bees in different colonies. No organ or part of a bee, or feces, was found to be invariably free of virus. Bees fed either by other bees that had been infected with pathogenic doses of ABPV, or with food containing up to 10(10) particles of ABPV, did not become obviously diseased but the virus content of their tissues temporarily increased. However, bees either fed with at least 10(11) ABPV particles each, or injected with at least 10(2) particles, became diseased and died, and their abnormal behavior was possibly attributable to the changes observed in their brains. Feeding bees with sublethal doses of infective virus or injecting them with large doses of virus that had been inactivated by ultraviolet radiation, did not alter their susceptibility to lethal doses of the virus.
Bombus spp. are susceptible to ABPV and many apparently healthy individuals contain the virus. Several species of other genera of insects were unaffected by the virus. When apparently healthy bees were injected with some foreign substances their virus content increased and they developed acute paralysis.
The distal nerve process of hair plate sensilla and campaniform sensilla contains a special terminal structure in the form of a bundle of tubules herein designated the "tubular body." Physiological and morphological results indicate that compression at the site of this body probably acts as the stimulus at the cellular level. A ciliary structure separates an outer segment of the distal nerve process from the remaining distal fiber.
1. Specific gravity of mature larvae of worker honey bees is 1.045.
2. The osmotic pressure of worker larval blood in terms of freezing point lowering gives a value of -0.86°C., and the osmotic pressure decreases during pupation.
3. The pH of larval blood (measured at 25°) is near 6.8, varying with conditions in the hive.
4. The oxygen capacity of larval blood is within a reasonable error the amount that could be physically dissolved, and no evidence of a chemical carrier is found. The content decreases during spinning, when the larva is enclosed in a cocoon, because diffusion is cut down while consumption increases.
5. CO2 absorption curves indicate that the blood (of drone larvae) decreases in CO2 capacity and content during spinning of the cocoon, but the tension of CO2 increases, and the H ion concentration increases, giving evidence of loss of alkali reserve through the production of acid other than CO2. After spinning, pupal blood shows a decrease of CO2 tension and content, with little change in capacity, allowing the pH to return to approximately the initial level.
6. Variation in CO2 tension and, therefore, in CO2 content and pH of blood from larvae in the same stage may be assigned to variable distribution of larvae in the cells of the comb...