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Sample records for bumblebee colony fitness

  1. Impacts of inbreeding on bumblebee colony fitness under field conditions

    Directory of Open Access Journals (Sweden)

    Brown Mark JF

    2009-07-01

    Full Text Available Abstract Background Inbreeding and the loss of genetic diversity are known to be significant threats to small, isolated populations. Hymenoptera represent a special case regarding the impact of inbreeding. Haplodiploidy may permit purging of deleterious recessive alleles in haploid males, meaning inbreeding depression is reduced relative to diploid species. In contrast, the impact of inbreeding may be exacerbated in Hymenopteran species that have a single-locus complementary sex determination system, due to the production of sterile or inviable diploid males. We investigated the costs of brother-sister mating in the bumblebee Bombus terrestris. We compared inbred colonies that produced diploid males and inbred colonies that did not produce diploid males with outbred colonies. Mating, hibernation and colony founding took place in the laboratory. Once colonies had produced 15 offspring they were placed in the field and left to forage under natural conditions. Results The diploid male colonies had a significantly reduced fitness compared to regular inbred and outbred colonies; they had slower growth rates in the laboratory, survived for a shorter time period under field conditions and produced significantly fewer offspring overall. No differences in success were found between non-diploid male inbred colonies and outbred colonies. Conclusion Our data illustrate that inbreeding exacts a considerable cost in Bombus terrestris through the production of diploid males. We suggest that diploid males may act as indicators of the genetic health of populations, and that their detection could be used as an informative tool in hymenopteran conservation. We conclude that whilst haplodiploids may suffer less inbreeding depression than diploid species, they are still highly vulnerable to population fragmentation and reduced genetic diversity due to the extreme costs imposed by the production of diploid males.

  2. Social Learning in Bumblebees (Bombus impatiens): Worker Bumblebees Learn to Manipulate and Forage at Artificial Flowers by Observation and Communication within the Colony

    OpenAIRE

    Hamida B. Mirwan; Peter G. Kevan

    2013-01-01

    Social learning occurs when one individual learns from another, mainly conspecific, often by observation, imitation, or communication. Using artificial flowers, we studied social learning by allowing test bumblebees to (a) see dead bumblebees arranged in foraging positions or (b) watch live bumblebees actually foraging or (c) communicate with nestmates within their colony without having seen foraging. Artificial flowers made from 1.5 mL microcentrifuge tubes with closed caps were inserted thr...

  3. Social Learning in Bumblebees (Bombus impatiens: Worker Bumblebees Learn to Manipulate and Forage at Artificial Flowers by Observation and Communication within the Colony

    Directory of Open Access Journals (Sweden)

    Hamida B. Mirwan

    2013-01-01

    Full Text Available Social learning occurs when one individual learns from another, mainly conspecific, often by observation, imitation, or communication. Using artificial flowers, we studied social learning by allowing test bumblebees to (a see dead bumblebees arranged in foraging positions or (b watch live bumblebees actually foraging or (c communicate with nestmates within their colony without having seen foraging. Artificial flowers made from 1.5 mL microcentrifuge tubes with closed caps were inserted through the centres of blue 7 cm plastic discs as optical signals through which the bees could not forage. The reinforcer reward syrup was accessible only through holes in the sides of the tubes beneath the blue discs. Two colonies (A and B were used in tandem along with control (C and D colonies. No bee that was not exposed (i.e., from the control colonies (C and D to social learning discovered the access holes. Inside colony B, we imprisoned a group of bees that were prevented from seeing or watching. Bees that saw dead bumblebees in foraging positions, those that watched nest-mates foraging, and those that had only in-hive communication with successful foragers all foraged successfully. The means of in-hive communication are not understood and warrant intense investigation.

  4. The Effects of Pollen Protein Content on Colony Development of the Bumblebee, Bombus Terrestris L.

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    Baloglu Güney Hikmet

    2015-06-01

    Full Text Available The effects of pollen protein content on the colony development of Bombus terrestris were investigated by feeding queens and queenright colonies with four different pollen diets. We used three kinds of commercially available pure pollen (Cistus spp. 11.9%, Papaver somniferum 21.4%, and Sinapis arvensis 21.8% crude protein. We also used a mixture which was made up of equal weights of these pure pollens (18.4 % crude protein. All queens and colonies were fed with sugar syrup and pollen diets ad libitum (28 ± 1 ℃, 65 ± 5% RH. Until there were 50 workers reached, colonies fed with the Cistus pollen diet (167.4 ± 28.9 g consumed significantly more pollen than colonies fed with the Papaver pollen diet (140.7 ± 15.7 g, the mixed pollen diet (136.2 ± 20.1 g or colonies fed with the Sinapis pollen diet (132.4 ± 22.6 g. The date when there were 50 workers reached was approximately one week later in the colonies fed with the Cistus, and colonies fed with the Papaver diet than in the colonies fed with the Sinapis diet, and for colonies fed with the mixed pollen diets. Considering 8 tested criteria, the best performances were observed using the Sinapis, and using the mixed pollen diets. The lowest performances were observed using the Cistus pollen diet. Results showed that pollen sources play an important role in commercial bumblebee rearing. Results also showed that the polyfloral pollen diets are more suitable for mass rearing of bumblebees than the unifloral pollen diets.

  5. Use of Radioactive Gold, 198AU, to Study the Radius of Action of Colonies of Bumble-Bees (Bombus Sp.) with a View to Pollination of Cultivated Plants

    International Nuclear Information System (INIS)

    It is generally very easy to label a colony with a radioisotope, taking advantage of the constant exchange of food between individuals. Bumble-bees, although living in a colony, do not engage in direct exchange, but it has been shown that continual transfer takes place through the honey cells (secondary trophallaxia). In these conditions a bumble-bee colony can be labelled as easily as a hive of bees. Gold-198 was successfully used for the tests, which enabled us to obtain important and unpublished information on the behaviour of workers in bumble-bee colonies situated close to fields of leguminous crops, with a view to enhancing grain production. Questions that have been investigated by this method include the time required to become familiarized to a new site, fixation on a particular species of plant, the radius of action and the determinate character of the flight paths and the honey-gathering sectors. (author)

  6. Sex ratio variation in the bumblebee Bombus terrestris

    DEFF Research Database (Denmark)

    Duchateau, Marie José; Velthuis, Hayo H. W.; Boomsma, Jacobus Jan

    2004-01-01

    Bombus terrestris, bumblebees, colony development, queen control, reproductive strategies, sex allocation......Bombus terrestris, bumblebees, colony development, queen control, reproductive strategies, sex allocation...

  7. Sperm influences female hibernation success, survival and fitness in the bumble-bee Bombus terrestris

    DEFF Research Database (Denmark)

    Baer, Boris; Schmid-Hempel, Paul

    2005-01-01

    . Using the bumble-bee Bombus terrestris, we artificially inseminated queens (females) with sperm from one or several males and show that sire groups (groups of brother males) vary in their effects on queen hibernation survival, longevity and fitness. In addition, multiply inseminated queens always had...... a lower performance as compared to singly inseminated queens. Apart from these main effects, sire groups (in situations of multiple insemination) affected queen longevity and fitness not independently of each other, i.e. certain sire group combinations were more harmful to queens than others. So far...

  8. No trade-off between learning speed and associative flexibility in bumblebees: a reversal learning test with multiple colonies.

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    Nigel E Raine

    Full Text Available Potential trade-offs between learning speed and memory-related performance could be important factors in the evolution of learning. Here, we test whether rapid learning interferes with the acquisition of new information using a reversal learning paradigm. Bumblebees (Bombus terrestris were trained to associate yellow with a floral reward. Subsequently the association between colour and reward was reversed, meaning bees then had to learn to visit blue flowers. We demonstrate that individuals that were fast to learn yellow as a predictor of reward were also quick to reverse this association. Furthermore, overnight memory retention tests suggest that faster learning individuals are also better at retaining previously learned information. There is also an effect of relatedness: colonies whose workers were fast to learn the association between yellow and reward also reversed this association rapidly. These results are inconsistent with a trade-off between learning speed and the reversal of a previously made association. On the contrary, they suggest that differences in learning performance and cognitive (behavioural flexibility could reflect more general differences in colony learning ability. Hence, this study provides additional evidence to support the idea that rapid learning and behavioural flexibility have adaptive value.

  9. No trade-off between learning speed and associative flexibility in bumblebees: a reversal learning test with multiple colonies

    OpenAIRE

    Raine, Nigel E.; Chittka, Lars

    2012-01-01

    Potential trade-offs between learning speed and memory-related performance could be important factors in the evolution of learning. Here, we test whether rapid learning interferes with the acquisition of new information using a reversal learning paradigm. Bumblebees (Bombus terrestris) were trained to associate yellow with a floral reward. Subsequently the association between colour and reward was reversed, meaning bees then had to learn to visit blue flowers. We demonstrate that individuals ...

  10. Distribution and diversity of Nosema bombi (Microsporidia: Nosematidae) in the natural populations of bumblebees (Bombus spp.) from West Siberia.

    Science.gov (United States)

    Vavilova, Valeriya; Sormacheva, Irina; Woyciechowski, Michal; Eremeeva, Natalia; Fet, Victor; Strachecka, Aneta; Bayborodin, Sergey I; Blinov, Alexander

    2015-09-01

    Nosema bombi is an obligate intracellular parasite of bumblebees (Hymenoptera, Bombus spp.), which has significant negative effect on individual bumblebees, colony fitness, and development. Recently, several new genetic variants of N. bombi without a defined taxonomic status were identified in natural bumblebee populations from Russia, China, and several European countries, as well as N. ceranae, originally isolated from honey bees, was described in bumblebee species. Thus, it is required to investigate more Nosema variability in bumblebee populations for identifying new genetic Nosema variants. In our study, we used several methods such as total DNA isolation, polymerase chain reaction (PCR) amplification, cloning, sequencing, and comparative and phylogenetic analysis to investigate a prevalence of N. bombi and its diversity in the natural populations of bumblebees across West Siberia. DNA was extracted from intestinal bumblebee tissues. Identification of the parasite was conducted, using PCR with primers specific for the ribosomal RNA gene cluster and methionine aminopeptidase 2 gene of N. bombi followed by sequencing. Seven hundred twenty-seven individual bumblebees belonging to 16 species were tested; 64 specimens revealed presence of the parasite. Prevalence of Nosema bombi infection was different in each region and varied from 4 to 20 %. No infection was found in Bombus agrorum (n = 194) and Bombus equestris (n = 132), both common bumblebees in West Siberia. Three different genetic variants of the same species, N. bombi, were identified. The first variant belonged to N. bombi (AY008373) identified by Fies et al. (J Apicult Res 40:91-96, 2001), second (N. bombi WS2) was identical to the West Siberian variant identified by Szentgyörgyi et al. (Polish Journal of Ecology 59:599-610, 2011), and the last variant, N. bombi WS3, was new. The results led us to suggest that the prevalence of the N. bombi is related to the population structure of bumblebees and

  11. The psychophysics of sugar concentration discrimination and contrast evaluation in bumblebees.

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    Nachev, Vladislav; Thomson, James D; Winter, York

    2013-05-01

    The capacity to discriminate between choice options is crucial for a decision-maker to avoid unprofitable options. The physical properties of rewards are presumed to be represented on context-dependent, nonlinear cognitive scales that may systematically influence reward expectation and thus choice behavior. In this study, we investigated the discrimination performance of free-flying bumblebee workers (Bombus impatiens) in a choice between sucrose solutions with different concentrations. We conducted two-alternative free choice experiments on two B. impatiens colonies containing some electronically tagged bumblebees foraging at an array of computer-automated artificial flowers that recorded individual choices. We mimicked natural foraging conditions by allowing uncertainty in the probability of reward delivery while maintaining certainty in reward concentration. We used a Bayesian approach to fit psychometric functions, relating the strength of preference for the higher concentration option to the relative intensity of the presented stimuli. Psychometric analysis was performed on visitation data from individually marked bumblebees and pooled data from unmarked individuals. Bumblebees preferred the more concentrated sugar solutions at high stimulus intensities and showed no preference at low stimulus intensities. The obtained psychometric function is consistent with reward evaluation based on perceived concentration contrast between choices. We found no evidence that bumblebees reduce reward expectations upon experiencing non-rewarded visits. We compare psychometric function parameters between the bumblebee B. impatiens and the flower bat Glossophaga commissarisi and discuss the relevance of psychophysics for pollinator-exerted selection pressures on plants. PMID:23179111

  12. Rearing and foraging affects bumblebee (Bombus terrestris) gut microbiota.

    Science.gov (United States)

    Newbold, Lindsay K; Oliver, Anna E; Cuthbertson, Leah; Walkington, Sarah E; Gweon, Hyun S; Heard, Matthew S; van der Gast, Christopher J

    2015-08-01

    Bumblebees are ecologically and economically important as pollinators of crop and wild plants, especially in temperate systems. Species, such as the buff-tailed bumblebee (Bombus terrestris), are reared commercially to pollinate high-value crops. Their highly specific gut microbiota, characterized by low diversity, may affect nutrition and immunity and are likely to be important for fitness and colony health. However, little is known about how environmental factors affect bacterial community structure. We analysed the gut microbiota from three groups of worker bumblebees (B. terrestris) from distinct colonies that varied in rearing and foraging characteristics: commercially reared with restricted foraging (RR); commercially reared with outside foraging (RF); and wild-caught workers (W). Contrary to previous studies, which indicate that bacterial communities are highly conserved across workers, we found that RF individuals had an intermediate community structure compared with RR and W types. Further, this was shaped by differences in the abundances of common operational taxonomic units (OTUs) and the diversity of rare OTUs present, which we propose results from an increase in the variety of carbohydrates obtained through foraging. PMID:25994560

  13. Optimizing supplementary pollen mixtures for bumblebeeBombus terrestris colonies based on colony reproductive variables%地熊蜂蜂群发育性状评价及其饲料花粉配比优化

    Institute of Scientific and Technical Information of China (English)

    盖琴宝; 周志勇; 张红; 黄家兴; 安建东

    2015-01-01

    [目的] 为了明确熊蜂蜂群发育过程中具有代表性的性状指标及其饲料花粉最优配比.[方法]以山杏Armeniaca sibirica花粉、山柳Salix caprea花粉和油菜Brassica rapa花粉为原料,通过{3,3}混料设计得到7种配比的混合花粉,分析不同混合花粉对地熊蜂Bombus terrestris (L.)无王工蜂群的产卵前时间、幼虫拖出数、幼虫总数量、幼虫总重量、蛹总数量、蛹总重量、雄蜂出房时间、出房雄蜂数量和雄蜂出生重9个蜂群性状指标的影响,使用主成分分析对蜂群性状指标进行综合评价,并通过混料回归模型预测熊蜂蜂群饲养过程中的最优花粉配比.[结果] 地熊蜂无王工蜂群发育过程的9个性状指标可以归纳为幼虫发育、蛹发育、成蜂发育、蜂群发育周期4类评价因子,其中幼虫总数量、蛹总重量、雄蜂出生重、产卵前时间和雄蜂出房时间是 5个主要性状指标;以蜂群主要性状指标为评价依据,得出蜂群饲养过程中最优花粉配比:当以油菜花粉单独饲喂蜂群时蜂群产卵前时间短、幼虫总数量最多、蛹总重量最大,当山杏花粉、山柳花粉和油菜花粉以1︰1.5︰1.5比例饲喂蜂群时雄蜂出房时间最短,当山柳花粉和油菜花粉以3︰1比例饲喂蜂群时雄蜂出生重最大.[结论] 明确了地熊蜂无王工蜂群发育过程中的重要性状指标和饲料花粉最优配比,为进一步研究商品化熊蜂群不同发育阶段的营养需求奠定了基础.%[Objectives]To measure reproductive variables of bumblebee colonies and optimize supplementary pollen mixtures based on these.[Methods] Three types of pollen, apricot (Armeniaca sibirica), willow (Salix caprea), and oilseed rape (Brassica rapa) were mixed following a {3,3} mixture design to obtain seven pollen mixtures. Nine reproductive variables including egg laying delay, larval ejection, total number of larvae, total weight of larvae, total number of pupae

  14. Hygienic food to reduce pathogen risk to bumblebees.

    Science.gov (United States)

    Graystock, P; Jones, J C; Pamminger, T; Parkinson, J F; Norman, V; Blane, E J; Rothstein, L; Wäckers, F; Goulson, D; Hughes, W O H

    2016-05-01

    Bumblebees are ecologically and economically important pollinators, and the value of bumblebees for crop pollination has led to the commercial production and exportation/importation of colonies on a global scale. Commercially produced bumblebee colonies can carry with them infectious parasites, which can both reduce the health of the colonies and spillover to wild bees, with potentially serious consequences. The presence of parasites in commercially produced bumblebee colonies is in part because colonies are reared on pollen collected from honey bees, which often contains a diversity of microbial parasites. In response to this threat, part of the industry has started to irradiate pollen used for bumblebee rearing. However, to date there is limited data published on the efficacy of this treatment. Here we examine the effect of gamma irradiation and an experimental ozone treatment on the presence and viability of parasites in honey bee pollen. While untreated pollen contained numerous viable parasites, we find that gamma irradiation reduced the viability of parasites in pollen, but did not eliminate parasites entirely. Ozone treatment appeared to be less effective than gamma irradiation, while an artificial pollen substitute was, as expected, entirely free of parasites. The results suggest that the irradiation of pollen before using it to rear bumblebee colonies is a sensible method which will help reduce the incidence of parasite infections in commercially produced bumblebee colonies, but that further optimisation, or the use of a nutritionally equivalent artificial pollen substitute, may be needed to fully eliminate this route of disease entry into factories. PMID:26970260

  15. Bumblebee sex ratios: why do bumblebees produce so many males?

    OpenAIRE

    Beekman, M; Stratum, P. van

    1998-01-01

    Sex investment ratios in populations of bumblebees are male biased, which contradicts theoretical predictions. Male-biased investment ratios in eusocial Hymenoptera are assumed to be non-stable for both the queen and her workers. In this paper, we show that male-biased sex allocation does not necessarily decrease fitness in the bumblebee Bombus terrestris. A male-biased investment ratio can be the result of an optimal allocation of resources when resources are scarce if (i) there is a large c...

  16. The relationship between managed bees and the prevalence of parasites in bumblebees

    Directory of Open Access Journals (Sweden)

    Peter Graystock

    2014-08-01

    Full Text Available Honey bees and, more recently, bumblebees have been domesticated and are now managed commercially primarily for crop pollination, mixing with wild pollinators during foraging on shared flower resources. There is mounting evidence that managed honey bees or commercially produced bumblebees may affect the health of wild pollinators such as bumblebees by increasing competition for resources and the prevalence of parasites in wild bees. Here we screened 764 bumblebees from around five greenhouses that either used commercially produced bumblebees or did not, as well as bumblebees from 10 colonies placed at two sites either close to or far from a honey bee apiary, for the parasites Apicystis bombi, Crithidia bombi, Nosema bombi, N. ceranae, N. apis and deformed wing virus. We found that A. bombi and C. bombi were more prevalent around greenhouses using commercially produced bumblebees, while C. bombi was 18% more prevalent in bumblebees at the site near to the honey bee apiary than those at the site far from the apiary. Whilst these results are from only a limited number of sites, they support previous reports of parasite spillover from commercially produced bumblebees to wild bumblebees, and suggest that the impact of stress from competing with managed bees or the vectoring of parasites by them on parasite prevalence in wild bees needs further investigation. It appears increasingly likely that the use of managed bees comes at a cost of increased parasites in wild bumblebees, which is not only a concern for bumblebee conservation, but which may impact other pollinators as well.

  17. Mite species inhabiting commercial bumblebee (Bombus terrestris) nests in Polish greenhouses

    OpenAIRE

    Rożej, Elżbieta; Witaliński, Wojciech; Szentgyörgyi, Hajnalka; Wantuch, Marta; Moroń, Dawid; Woyciechowski, Michal

    2012-01-01

    Nests of social insects are usually inhabited by various mite species that feed on pollen, other micro-arthropods or are parasitic. Well-known negative effects of worldwide economic importance are caused by mites parasitizing honeybee colonies. Lately, attention has focused on the endoparasitic mite Locustacarus buchneri that has been found in commercial bumblebees. However, little is known of other mites associated with commercial bumblebee nests. Transportation of commercial bumblebee colon...

  18. Ant colony clustering with fitness perception and pheromone diffusion for community detection in complex networks

    Science.gov (United States)

    Ji, Junzhong; Song, Xiangjing; Liu, Chunnian; Zhang, Xiuzhen

    2013-08-01

    Community structure detection in complex networks has been intensively investigated in recent years. In this paper, we propose an adaptive approach based on ant colony clustering to discover communities in a complex network. The focus of the method is the clustering process of an ant colony in a virtual grid, where each ant represents a node in the complex network. During the ant colony search, the method uses a new fitness function to percept local environment and employs a pheromone diffusion model as a global information feedback mechanism to realize information exchange among ants. A significant advantage of our method is that the locations in the grid environment and the connections of the complex network structure are simultaneously taken into account in ants moving. Experimental results on computer-generated and real-world networks show the capability of our method to successfully detect community structures.

  19. Effectiveness of native bumblebees as pollinators of the alien invasive plant Impatiens glandulifera (Balsaminaceae in Ireland

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    Jane C. Stout

    2009-07-01

    Full Text Available Flowers of alien invasive plants can be pollen limited due to a lack of effective pollinators. The alien Impatiens glandulifera is predominantly visited by bumblebees in its invaded range. There bumblebees pollinate I. glandulifera, but it remains unclear whether foraging behaviour or bumblebee or flower morphology affects effectiveness. We investigated the effectiveness of native bumblebee (Bombus pascuorum pollinators in Ireland by quantifying pollen deposition and removal, and seed production after a single bumblebee visit. Morphological characteristics of flowers and bumblebee body parts were measured to determine their influence on pollen deposition and removal. B. pascuorum is a highly effective pollinator of the alien due to its high visitation frequency, the morphological fit with flowers and individuals removing large pollen quantities and inducing maximum seed set after a single visit. The impact of native bumblebees on I. glandulifera pollination and the implications of the pollination mechanism of the alien for its successful spread are discussed.

  20. Fitness of isogenic colony morphology variants of Pseudomonas aeruginosa in murine airway infection.

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    Elza Rakhimova

    Full Text Available Chronic lung infections with Pseudomonas aeruginosa are associated with the diversification of the persisting clone into niche specialists and morphotypes, a phenomenon called 'dissociative behaviour'. To explore the potential of P. aeruginosa to change its morphotype by single step loss-of-function mutagenesis, a signature-tagged mini-Tn5 plasposon library of the cystic fibrosis airway isolate TBCF10839 was screened for colony morphology variants under nine different conditions in vitro. Transposon insertion into 1% of the genome changed colony morphology into eight discernable morphotypes. Half of the 55 targets encode features of primary or secondary metabolism whereby quinolone production was frequently affected. In the other half the transposon had inserted into genes of the functional categories transport, regulation or motility/chemotaxis. To mimic dissociative behaviour of isogenic strains in lungs, pools of 25 colony morphology variants were tested for competitive fitness in an acute murine airway infection model. Six of the 55 mutants either grew better or worse in vivo than in vitro, respectively. Metabolic proficiency of the colony morphology variant was a key determinant for survival in murine airways. The most common morphotype of self-destructive autolysis did unexpectedly not impair fitness. Transposon insertions into homologous genes of strain PAO1 did not reproduce the TBCF10839 mutant morphotypes for 16 of 19 examined loci pointing to an important role of the genetic background on colony morphology. Depending on the chosen P. aeruginosa strain, functional genome scans will explore other areas of the evolutionary landscape. Based on our discordant findings of mutant phenotypes in P. aeruginosa strains PAO1, PA14 and TBCF10839, we conclude that the current focus on few reference strains may miss modes of niche adaptation and dissociative behaviour that are relevant for the microevolution of complex traits in the wild.

  1. Chronic neonicotinoid pesticide exposure and parasite stress differentially affects learning in honeybees and bumblebees.

    Science.gov (United States)

    Piiroinen, Saija; Goulson, Dave

    2016-04-13

    Learning and memory are crucial functions which enable insect pollinators to efficiently locate and extract floral rewards. Exposure to pesticides or infection by parasites may cause subtle but ecologically important changes in cognitive functions of pollinators. The potential interactive effects of these stressors on learning and memory have not yet been explored. Furthermore, sensitivity to stressors may differ between species, but few studies have compared responses in different species. Here, we show that chronic exposure to field-realistic levels of the neonicotinoid clothianidin impaired olfactory learning acquisition in honeybees, leading to potential impacts on colony fitness, but not in bumblebees. Infection by the microsporidian parasiteNosema ceranaeslightly impaired learning in honeybees, but no interactive effects were observed.Nosemadid not infect bumblebees (3% infection success). Nevertheless,Nosema-treated bumblebees had a slightly lower rate of learning than controls, but faster learning in combination with neonicotinoid exposure. This highlights the potential for complex interactive effects of stressors on learning. Our results underline that one cannot readily extrapolate findings from one bee species to others. This has important implications for regulatory risk assessments which generally use honeybees as a model for all bees. PMID:27053744

  2. Reproductive disturbance of Japanese bumblebees by the introduced European bumblebee Bombus terrestris

    Science.gov (United States)

    Kondo, Natsuko Ito; Yamanaka, Daisei; Kanbe, Yuya; Kunitake, Yoko Kawate; Yoneda, Masahiro; Tsuchida, Koji; Goka, Koichi

    2009-04-01

    The European bumblebee, Bombus terrestris, is an invasive eusocial species whose distribution is expanding greatly beyond its native range because numerous colonies are imported to or locally produced in non-native countries for pollination of agricultural crops. Closely related species exist in Japan where the unrestricted import and use of B. terrestris has resulted in the establishment of wild colonies. Laboratory studies previously showed that B. terrestris and Japanese native species can copulate and produce fertilized eggs. Although these eggs do not hatch, the interspecific mating can cause a serious reproductive disturbance to native bumblebees. In this study, we determined the frequencies of interspecies mating between B. terrestris males and native bumblebee queens in the wild on the islands of Hokkaido and Honshu by analyzing the DNA sequences of spermatozoa stored in spermathecae of native queens. We found that 20.2% of B. hypocrita hypocrita queens and 30.2% of B. hypocrita sapporoensis queens had spermatozoa of B. terrestris males in their spermathecae. Given that a Bombus queen generally mates only once in her life, such high frequencies of interspecific mating with B. terrestris pose serious threats to the populations of native bumblebees in Japan.

  3. Olfactory learning and memory in the bumblebee Bombus occidentalis

    Science.gov (United States)

    Riveros, Andre J.; Gronenberg, Wulfila

    2009-07-01

    In many respects, the behavior of bumblebees is similar to that of the closely related honeybees, a long-standing model system for learning and memory research. Living in smaller and less regulated colonies, bumblebees are physiologically more robust and thus have advantages in particular for indoor experiments. Here, we report results on Pavlovian odor conditioning of bumblebees using the proboscis extension reflex (PER) that has been successfully used in honeybee learning research. We examine the effect of age, body size, and experience on learning and memory performance. We find that age does not affect learning and memory ability, while body size positively correlates with memory performance. Foraging experience seems not to be necessary for learning to occur, but it may contribute to learning performance as bumblebees with more foraging experience on average were better learners. The PER represents a reliable tool for learning and memory research in bumblebees and allows examining interspecific similarities and differences of honeybee and bumblebee behavior, which we discuss in the context of social organization.

  4. First Neotropical Mutualistic Associations in Bumblebee Nests (Hymenoptera: Apidae)

    OpenAIRE

    Gabriela Chavarria

    1994-01-01

    Ectosymbionts of bumblebee nests of Bombus ephippiatus are recorded for first time from the American Tropics. An overview of this interaction is provided.“The insect colony and its immediate environment can be thought of as an island which symbiotic organisms are continuously attempting to colonize”

  5. Bumblebees and solitary bees

    DEFF Research Database (Denmark)

    Henriksen, Casper Christian I

    quadrupling the organic arable area. Instead, bumblebees responded to perennial flower resources in the road verge/grassy field border and semi-natural habitats in the landscape. Organically managed arable fields with mostly annual non-crop flowering plants in intensively cultivated landscapes probably played......Summary: The effects of farming system, flower resources and semi-natural habitats on bumblebees and solitary bees in intensively cultivated landscapes in Denmark were investigated in two sets of studies, in 2011 and 2012. The pan trap colour preferences of bumblebees and solitary bees were also...... of dicotyledonous herbs in the flowering stage (quantity) and density of plants containing combined high pollen and nectar amounts (quality). Potential flower and nesting resources (referred to as semi-natural habitats) in the surrounding landscape were assessed using up-to-date, spatially precise...

  6. Bumblebee learning and memory is impaired by chronic exposure to a neonicotinoid pesticide.

    Science.gov (United States)

    Stanley, Dara A; Smith, Karen E; Raine, Nigel E

    2015-01-01

    Bumblebees are exposed to pesticides applied for crop protection while foraging on treated plants, with increasing evidence suggesting that this sublethal exposure has implications for pollinator declines. The challenges of navigating and learning to manipulate many different flowers underline the critical role learning plays for the foraging success and survival of bees. We assessed the impacts of both acute and chronic exposure to field-realistic levels of a widely applied neonicotinoid insecticide, thiamethoxam, on bumblebee odour learning and memory. Although bees exposed to acute doses showed conditioned responses less frequently than controls, we found no difference in the number of individuals able to learn at field-realistic exposure levels. However, following chronic pesticide exposure, bees exposed to field-realistic levels learnt more slowly and their short-term memory was significantly impaired following exposure to 2.4 ppb pesticide. These results indicate that field-realistic pesticide exposure can have appreciable impacts on learning and memory, with potential implications for essential individual behaviour and colony fitness. PMID:26568480

  7. Altered Competitive Fitness, Antimicrobial Susceptibility, and Cellular Morphology in a Triclosan-Induced Small-Colony Variant of Staphylococcus aureus

    OpenAIRE

    Forbes, Sarah; Latimer, Joe; Bazaid, Abdulrahman; McBain, Andrew J.

    2015-01-01

    Staphylococcus aureus can produce small-colony variants (SCVs) that express various phenotypes. While their significance is unclear, SCV propagation may be influenced by relative fitness, antimicrobial susceptibility, and the underlying mechanism. We have investigated triclosan-induced generation of SCVs in six S. aureus strains, including methicillin-resistant S. aureus (MRSA). Parent strains (P0) were repeatedly passaged on concentration gradients of triclosan using a solid-state exposure s...

  8. Radiative corrections in bumblebee electrodynamics

    Directory of Open Access Journals (Sweden)

    R.V. Maluf

    2015-10-01

    Full Text Available We investigate some quantum features of the bumblebee electrodynamics in flat spacetimes. The bumblebee field is a vector field that leads to a spontaneous Lorentz symmetry breaking. For a smooth quadratic potential, the massless excitation (Nambu–Goldstone boson can be identified as the photon, transversal to the vacuum expectation value of the bumblebee field. Besides, there is a massive excitation associated with the longitudinal mode and whose presence leads to instability in the spectrum of the theory. By using the principal-value prescription, we show that no one-loop radiative corrections to the mass term is generated. Moreover, the bumblebee self-energy is not transverse, showing that the propagation of the longitudinal mode cannot be excluded from the effective theory.

  9. Insecticide resistence of bumblebee species

    Czech Academy of Sciences Publication Activity Database

    Zarevúcka, Marie

    Rijeka: InTech, 2013 - (Chamy, R.; Rosenkranz, F.), s. 207-228 ISBN 978-953-51-1154-2 R&D Projects: GA ČR GA203/09/1446; GA TA ČR TA01020969 Institutional support: RVO:61388963 Keywords : bumblebee * insecticide Subject RIV: CC - Organic Chemistry http://www.intechopen.com/books/biodegradation-life-of-science/insecticide-resistence-of-bumblebee-species

  10. Flower choice copying in bumblebees

    OpenAIRE

    Worden, Bradley D; Papaj, Daniel R

    2005-01-01

    We tested a hypothesis originating with Darwin that bees outside the nest exhibit social learning in flower choices. Naive bumblebees, Bombus impatiens, were allowed to observe trained bees or artificial bees forage from orange or green flowers. Subsequently, observers of bees on green flowers landed more often on green flowers than non-observing controls or observers of models on orange flowers. These results demonstrate that bumblebees can change flower choice by observations of non-nest ma...

  11. The Preference for Symmetry in Flower-Naive and Not-so-Naive Bumblebees

    Science.gov (United States)

    Plowright, C. M. S.; Evans, S. A.; Leung, J. Chew; Collin, C. A.

    2011-01-01

    Truly flower-naive bumblebees, with no prior rewarded experience for visits on any visual patterns outside the colony, were tested for their choice of bilaterally symmetric over asymmetric patterns in a radial-arm maze. No preference for symmetry was found. Prior training with rewarded black and white disks did, however, lead to a significant…

  12. Workers dominate male production in the neotropical bumblebee Bombus wilmattae (Hymenoptera: Apidae

    Directory of Open Access Journals (Sweden)

    Vandame Rémy

    2011-06-01

    Full Text Available Abstract Background Cooperation and conflict in social insects are closely linked to the genetic structure of the colony. Kin selection theory predicts conflict over the production of males between the workers and the queen and between the workers themselves, depending on intra-colonial relatedness but also on other factors like colony efficiency, sex ratios, cost of worker reproduction and worker dominance behaviour. In most bumblebee (Bombus species the queen wins this conflict and often dominates male production. However, most studies in bumblebees have been conducted with only a few selected, mostly single mated species from temperate climate regions. Here we study the genetic colony composition of the facultative polyandrous neotropical bumblebee Bombus wilmattae, to assess the outcome of the queen-worker conflict over male production and to detect potential worker policing. Results A total of 120 males from five colonies were genotyped with up to nine microsatellite markers to infer their parentage. Four of the five colonies were queen right at point of time of male sampling, while one had an uncertain queen status. The workers clearly dominated production of males with an average of 84.9% +/- 14.3% of males being worker sons. In the two doubly mated colonies 62.5% and 96.7% of the male offspring originated from workers and both patrilines participated in male production. Inferring the mother genotypes from the male offspring, between four to eight workers participated in the production of males. Conclusions In this study we show that the workers clearly win the queen-worker conflict over male production in B. wilmattae, which sets them apart from the temperate bumblebee species studied so far. Workers clearly dominated male production in the singly as well the doubly mated colonies, with up to eight workers producing male offspring in a single colony. Moreover no monopolization of reproduction by single workers occurred.

  13. Fitness

    Science.gov (United States)

    ... gov home http://www.girlshealth.gov/ Home Fitness Fitness Want to look and feel your best? Physical ... are? Check out this info: What is physical fitness? top Physical fitness means you can do everyday ...

  14. Size determines antennal sensitivity and behavioral threshold to odors in bumblebee workers

    Science.gov (United States)

    Spaethe, Johannes; Brockmann, Axel; Halbig, Christine; Tautz, Jürgen

    2007-09-01

    The eusocial bumblebees exhibit pronounced size variation among workers of the same colony. Differently sized workers engage in different tasks (alloethism); large individuals are found to have a higher probability to leave the colony and search for food, whereas small workers tend to stay inside the nest and attend to nest duties. We investigated the effect of size variation on morphology and physiology of the peripheral olfactory system and the behavioral response thresholds to odors in workers of Bombus terrestris. Number and density of olfactory sensilla on the antennae correlate significantly with worker size. Consistent with these morphological changes, we found that antennal sensitivity to odors increases with body size. Antennae of large individuals show higher electroantennogram responses to a given odor concentration than those of smaller nestmates. This finding indicates that large antennae exhibit an increased capability to catch odor molecules and thus are more sensitive to odors than small antennae. We confirmed this prediction in a dual choice behavioral experiment showing that large workers indeed are able to respond correctly to much lower odor concentrations than small workers. Learning performance in these experiments did not differ between small and large bumblebees. Our results clearly show that, in the social bumblebees, variation in olfactory sensilla number due to size differences among workers strongly affects individual odor sensitivity. We speculate that superior odor sensitivity of large workers has favored size-related division of labor in bumblebee colonies.

  15. Neonicotinoid pesticide exposure impairs crop pollination services provided by bumblebees

    Science.gov (United States)

    Stanley, Dara A.; Garratt, Michael P. D.; Wickens, Jennifer B.; Wickens, Victoria J.; Potts, Simon G.; Raine, Nigel E.

    2015-12-01

    Recent concern over global pollinator declines has led to considerable research on the effects of pesticides on bees. Although pesticides are typically not encountered at lethal levels in the field, there is growing evidence indicating that exposure to field-realistic levels can have sublethal effects on bees, affecting their foraging behaviour, homing ability and reproductive success. Bees are essential for the pollination of a wide variety of crops and the majority of wild flowering plants, but until now research on pesticide effects has been limited to direct effects on bees themselves and not on the pollination services they provide. Here we show the first evidence to our knowledge that pesticide exposure can reduce the pollination services bumblebees deliver to apples, a crop of global economic importance. Bumblebee colonies exposed to a neonicotinoid pesticide provided lower visitation rates to apple trees and collected pollen less often. Most importantly, these pesticide-exposed colonies produced apples containing fewer seeds, demonstrating a reduced delivery of pollination services. Our results also indicate that reduced pollination service delivery is not due to pesticide-induced changes in individual bee behaviour, but most likely due to effects at the colony level. These findings show that pesticide exposure can impair the ability of bees to provide pollination services, with important implications for both the sustained delivery of stable crop yields and the functioning of natural ecosystems.

  16. Nest wax triggers worker reproduction in the bumblebee Bombus terrestris.

    Science.gov (United States)

    Rottler-Hoermann, Ann-Marie; Schulz, Stefan; Ayasse, Manfred

    2016-01-01

    Social insects are well known for their high level of cooperation. Workers of the primitively eusocial bumblebee Bombus terrestris are able to produce male offspring in the presence of a queen. Nonetheless, they only compete for reproduction, in the so-called competition phase, when the workforce is large enough to support the rearing of reproductives. So far, little is known about the proximate mechanisms underlying the shift between altruism and selfish behaviour in bumblebee workers. In this study, we have examined the influence of chemical cues from the nest wax on the onset of worker reproduction. Chemical analyses of wax extracts have revealed that the patterns and amounts of cuticular lipids change considerably during colony development. These changes in wax scent mirror worker abundance and the presence of fertile workers. In bioassays with queen-right worker groups, wax affects the dominance behaviour and ovarian development of workers. When exposed to wax from a colony in competition phase, workers start to compete for reproduction. We suggest that wax scent enables workers to time their reproduction by providing essential information concerning the social condition of the colony. PMID:26909189

  17. Growth Rate of Bumblebee Larvae is Related to Pollen Amino Acids.

    Science.gov (United States)

    Moerman, Romain; Vanderplanck, Maryse; Roger, Nathalie; Declèves, Sylvain; Wathelet, Bernard; Rasmont, Pierre; Fournier, Denis; Michez, Denis

    2016-02-01

    The use of Bombus terrestris L. commercial colonies for outdoor and greenhouse crop pollination is currently widespread. Colony breeding includes bumblebee feeding, mostly by using the honeybee pollen loads of diverse palynological composition. Because the chemical content of pollen is highly variable, the choice of commercial blend should not be random but has to be carefully selected to ensure the optimal development of workers and then pollination efficacy. In this work, we compared the impact of three common commercial blends on the development of bumblebee microcolonies, namely, Actinidia deliciosa L., Cistus sp., and Salix sp. We focus on amino acids (i.e., composition and amount), as they are currently used as an indicator of diet performance. Five parameters were used to determine microcolonies growth rate: 1) number of eggs, 2) number of alive larvae, 3) number of ejected larvae, 4) number of pupae, and 5) total number of offspring. Syrup collection was also monitored to estimate energetic requirement for colony growth. Results revealed that the three commercial blends chemically differed in their amino acid contents, with those displaying higher concentrations (i.e., Salix sp. and A. deliciosa) accelerating microcolony development along with an increase of syrup collection. The advantages of rearing bumblebee commercial colonies using a pollen diet with an optimal amino acid content are discussed. PMID:26385047

  18. [Venomous stings in the tropical world: bite and sting accident by a bumblebee swarm in a rainy Venezuelan forest].

    Science.gov (United States)

    Rodríguez-Acosta, A; Guerrero, R; Reyes, M; Szymanska, B

    1998-01-01

    Two cases of poisoning produced by the unusual attack of colonies of insects from the family Bombidae, commonly known as bumblebees, are described. This type of poisoning may become severe toxicity and it is analyzed in the light of the latest findings. It is characterized by hemorrhagical symptoms, such as hematemesis and melaena. PMID:9842259

  19. Colony pace: a life-history trait affecting social insect epidemiology.

    Science.gov (United States)

    Buechel, Séverine Denise; Schmid-Hempel, Paul

    2016-01-13

    Among colonies of social insects, the worker turnover rate (colony 'pace') typically shows considerable variation. This has epidemiological consequences for parasites, because in 'fast-paced' colonies, with short-lived workers, the time of parasite residence in a given host will be reduced, and further transmission may thus get less likely. Here, we test this idea and ask whether pace is a life-history strategy against infectious parasites. We infected bumblebees (Bombus terrestris) with the infectious gut parasite Crithidia bombi, and experimentally manipulated birth and death rates to mimic slow and fast pace. We found that fewer workers and, importantly, fewer last-generation workers that are responsible for rearing sexuals were infected in colonies with faster pace. This translates into increased fitness in fast-paced colonies, as daughter queens exposed to fewer infected workers in the nest are less likely to become infected themselves, and have a higher chance of founding their own colonies in the next year. High worker turnover rate can thus act as a strategy of defence against a spreading infection in social insect colonies. PMID:26763696

  20. Dispersal of solitary bees and bumblebees in a winter oilseed rape field

    DEFF Research Database (Denmark)

    Calabuig, Isabel

    2000-01-01

    Dispersal distributions of solitary bees and bumblebees were studied in a winter oilseed rape field. Window-traps were placed in the rape field along a line transect perpendicular to the field edge. 19 species of solitary bees were recorded and all but four species are polylectic, including...... Brassicaceae as host-plant family. Through non-linear regression, the decline in solitary bee individuals versus distance from field edge significantly fitted a steep two-parameter exponential decay function. Activity of solitary bees was clearly highest within 30 metres from the field edge. Apparently......, solitary bees do not play any noteworthy role in the pollination of winter oilseed rape in Denmark. The traps yielded ten species of bumblebees, and a significant linear correlation was found between numbers of individuals and distance from the field edge. This result is attributed to bumblebee foraging...

  1. Sex, horizontal transmission, and multiple hosts prevent local adaptation of Crithidia bombi, a parasite of bumblebees (Bombus spp.)

    OpenAIRE

    Erler, Silvio; Popp, Mario; Wolf, Stephan; Lattorff, H Michael G

    2012-01-01

    Local adaptation within host-parasite systems can evolve by several non-exclusive drivers (e.g., host species-genetic adaptation; ecological conditions-ecological adaptation, and time-temporal adaptation). Social insects, especially bumblebees, with an annual colony life history not only provide an ideal system to test parasite transmission within and between different host colonies, but also parasite adaptation to specific host species and environments. Here, we study local adaptation in a m...

  2. Pollination of Greenhouse Tomatoes by the Mexican bumblebee Bombus ephippiatus (Hymenoptera: Apidae)

    OpenAIRE

    Carlos Hernan Vergara; Paula Fonseca-Buendía

    2012-01-01

    The Mexican native bumblebee Bombus ephippiatus Say was evaluated as a potential pollinator of greenhouse tomatoes (Solanum lycopersicon L.). The experiments were performed at San Andrés Cholula, Puebla, Mexico, from June to December 2004 in two 1 000 m2 greenhouses planted with tomatoes of the cultivar Mallory (Hazera ®). For the experiments, we used two colonies of Bombus ephippiatus, reared in the laboratory from queens captured in the field. Four treatments were applied to 20 study plant...

  3. Bumblebee flight in heavy turbulence

    CERN Document Server

    Engels, T; Schneider, K; Lehmann, F -O; Sesterhenn, J

    2016-01-01

    High-resolution numerical simulations of a tethered model bumblebee in forward flight are performed superimposing homogeneous isotropic turbulent fluctuations to the uniform inflow. Despite tremendous variation in turbulence intensity, between 17% and 99% with respect to the mean flow, we do not find significant changes in cycle-averaged aerodynamic forces, moments or flight power when averaged over realizations, compared to laminar inflow conditions. The variance of aerodynamic measures, however, significantly increases with increasing turbulence intensity, which may explain flight instabilities observed in freely flying bees.

  4. Immune gene expression in Bombus terrestris: signatures of infection despite strong variation among populations, colonies, and sister workers.

    Directory of Open Access Journals (Sweden)

    Franziska S Brunner

    Full Text Available Ecological immunology relies on variation in resistance to parasites. Colonies of the bumblebee Bombus terrestris vary in their susceptibility to the trypanosome gut parasite Crithidia bombi, which reduces colony fitness. To understand the possible origin of this variation in resistance we assayed the expression of 28 immunologically important genes in foraging workers. We deliberately included natural variation of the host "environment" by using bees from colonies collected in two locations and sampling active foraging workers that were not age controlled. Immune gene expression patterns in response to C. bombi showed remarkable variability even among genetically similar sisters. Nevertheless, expression varied with parasite exposure, among colonies and, perhaps surprisingly, strongly among populations (collection sites. While only the antimicrobial peptide abaecin is universally up regulated upon exposure, linear discriminant analysis suggests that the overall exposure effect is driven by a combination of several immune pathways and further immune functions such as ROS regulation. Also, the differences among colonies in their immune gene expression profiles provide clues to the mechanistic basis of well-known inter-colony variation in susceptibility to this parasite. Our results show that transcriptional responses to parasite exposure can be detected in ecologically heterogeneous groups despite strong background noise.

  5. Macrophage adaptation leads to parallel evolution of genetically diverse Escherichia coli small-colony variants with increased fitness in vivo and antibiotic collateral sensitivity.

    Science.gov (United States)

    Ramiro, Ricardo S; Costa, Henrique; Gordo, Isabel

    2016-09-01

    Small-colony variants (SCVs) are commonly observed in evolution experiments and clinical isolates, being associated with antibiotic resistance and persistent infections. We recently observed the repeated emergence of Escherichia coli SCVs during adaptation to the interaction with macrophages. To identify the genetic targets underlying the emergence of this clinically relevant morphotype, we performed whole-genome sequencing of independently evolved SCV clones. We uncovered novel mutational targets, not previously associated with SCVs (e.g. cydA, pepP) and observed widespread functional parallelism. All SCV clones had mutations in genes related to the electron-transport chain. As SCVs emerged during adaptation to macrophages, and often show increased antibiotic resistance, we measured SCV fitness inside macrophages and measured their antibiotic resistance profiles. SCVs had a fitness advantage inside macrophages and showed increased aminoglycoside resistance in vitro, but had collateral sensitivity to other antibiotics (e.g. tetracycline). Importantly, we observed similar results in vivo. SCVs had a fitness advantage upon colonization of the mouse gut, which could be tuned by antibiotic treatment: kanamycin (aminoglycoside) increased SCV fitness, but tetracycline strongly reduced it. Our results highlight the power of using experimental evolution as the basis for identifying the causes and consequences of adaptation during host-microbe interactions. PMID:27606007

  6. Chronic exposure to neonicotinoids increases neuronal vulnerability to mitochondrial dysfunction in the bumblebee (Bombus terrestris).

    Science.gov (United States)

    Moffat, Christopher; Pacheco, Joao Goncalves; Sharp, Sheila; Samson, Andrew J; Bollan, Karen A; Huang, Jeffrey; Buckland, Stephen T; Connolly, Christopher N

    2015-05-01

    The global decline in the abundance and diversity of insect pollinators could result from habitat loss, disease, and pesticide exposure. The contribution of the neonicotinoid insecticides (e.g., clothianidin and imidacloprid) to this decline is controversial, and key to understanding their risk is whether the astonishingly low levels found in the nectar and pollen of plants is sufficient to deliver neuroactive levels to their site of action: the bee brain. Here we show that bumblebees (Bombus terrestris audax) fed field levels [10 nM, 2.1 ppb (w/w)] of neonicotinoid accumulate between 4 and 10 nM in their brains within 3 days. Acute (minutes) exposure of cultured neurons to 10 nM clothianidin, but not imidacloprid, causes a nicotinic acetylcholine receptor-dependent rapid mitochondrial depolarization. However, a chronic (2 days) exposure to 1 nM imidacloprid leads to a receptor-dependent increased sensitivity to a normally innocuous level of acetylcholine, which now also causes rapid mitochondrial depolarization in neurons. Finally, colonies exposed to this level of imidacloprid show deficits in colony growth and nest condition compared with untreated colonies. These findings provide a mechanistic explanation for the poor navigation and foraging observed in neonicotinoid treated bumblebee colonies. PMID:25634958

  7. Ecological Variation in Response to Mass-Flowering Oilseed Rape and Surrounding Landscape Composition by Members of a Cryptic Bumblebee Complex.

    Directory of Open Access Journals (Sweden)

    Dara A Stanley

    Full Text Available The Bombus sensu stricto species complex is a widespread group of cryptic bumblebee species which are important pollinators of many crops and wild plants. These cryptic species have, until now, largely been grouped together in ecological studies, and so little is known about their individual colony densities, foraging ranges or habitat requirements, which can be influenced by land use at a landscape scale. We used mass-flowering oilseed rape fields as locations to sample bees of this complex, as well as the second most common visitor to oilseed rape B. lapidarius, and molecular RFLP methods to distinguish between the cryptic species. We then used microsatellite genotyping to identify sisters and estimate colony densities, and related both proportions of cryptic species and their colony densities to the composition of the landscape surrounding the fields. We found B. lucorum was the most common member of the complex present in oilseed rape followed by B. terrestris. B. cryptarum was also present in all but one site, with higher proportions found in the east of the study area. High numbers of bumblebee colonies were estimated to be using oilseed rape fields as a forage resource, with B. terrestris colony numbers higher than previous estimates from non-mass-flowering fields. We also found that the cryptic species responded differently to surrounding landscape composition: both relative proportions of B. cryptarum in samples and colony densities of B. lucorum were negatively associated with the amount of arable land in the landscape, while proportions and colony densities of other species did not respond to landscape variables at the scale measured. This suggests that the cryptic species have different ecological requirements (which may be scale-dependent and that oilseed rape can be an important forage resource for many colonies of bumblebees. Given this, we recommend sustainable management of this crop to benefit bumblebees.

  8. Predator crypsis enhances behaviourally mediated indirect effects on plants by altering bumblebee foraging preferences

    OpenAIRE

    Ings, Thomas C.; Chittka, Lars

    2009-01-01

    Predators of pollinators can influence pollination services and plant fitness via both consumptive (reducing pollinator density) and non-consumptive (altering pollinator behaviour) effects. However, a better knowledge of the mechanisms underlying behaviourally mediated indirect effects of predators is necessary to properly understand their role in community dynamics. We used the tripartite relationship between bumblebees, predatory crab spiders and flowers to ask whether behaviourally mediate...

  9. Pollination of Greenhouse Tomatoes by the Mexican bumblebee Bombus ephippiatus (Hymenoptera: Apidae

    Directory of Open Access Journals (Sweden)

    Carlos Hernan Vergara

    2012-04-01

    Full Text Available The Mexican native bumblebee Bombus ephippiatus Say was evaluated as a potential pollinator of greenhouse tomatoes (Solanum lycopersicon L.. The experiments were performed at San Andrés Cholula, Puebla, Mexico, from June to December 2004 in two 1 000 m2 greenhouses planted with tomatoes of the cultivar Mallory (Hazera ®. For the experiments, we used two colonies of Bombus ephippiatus, reared in the laboratory from queens captured in the field. Four treatments were applied to 20 study plants: pollination by bumble bees, manual pollination, pollination by mechanical vibration and no pollination (bagged flowers, no vibration. We measured percentage of flowers visited by bumble bees, number of seeds per fruit, maturing time, sugar content, fruit weight and fruit shape. All available flowers were visited by bumblebees, as measured by the degree of anther cone bruising. The number of seeds per fruit was higher for bumble bee-pollinated plants as compared with plants pollinated mechanically or not pollinated and was not significantly different between hand-pollinated and bumble bee-pollinated plants. Maturation time was significantly longer and sugar content, fresh weight and seed count were significantly higher for bumblebee pollinated flowers than for flowers pollinated manually or with no supplemental pollination, but did not differ with flowers pollinated mechanically.

  10. No effect of low-level chronic neonicotinoid exposure on bumblebee learning and fecundity.

    Science.gov (United States)

    Piiroinen, Saija; Botías, Cristina; Nicholls, Elizabeth; Goulson, Dave

    2016-01-01

    In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems. One of the most debated factors proposed to be contributing to pollinator declines is exposure to pesticides, particularly neonicotinoids, a widely used class of systemic insecticide. Also, newly emerging parasites and diseases, thought to be spread via contact with managed honeybees, may pose threats to other pollinators such as bumblebees. Compared to honeybees, bumblebees could be particularly vulnerable to the effects of stressors due to their smaller and more short-lived colonies. Here, we studied the effect of field-realistic, chronic clothianidin exposure and inoculation with the parasite Nosema ceranae on survival, fecundity, sugar water collection and learning using queenless Bombus terrestris audax microcolonies in the laboratory. Chronic exposure to 1 ppb clothianidin had no significant effects on the traits studied. Interestingly, pesticide exposure in combination with additional stress caused by harnessing bees for Proboscis Extension Response (PER) learning assays, led to an increase in mortality. In contrast to previous findings, the bees did not become infected by N. ceranae after experimental inoculation with the parasite spores, suggesting variability in host resistance or parasite virulence. However, this treatment induced a slight, short-term reduction in sugar water collection, potentially through stimulation of the immune system of the bees. Our results suggest that chronic exposure to 1 ppb clothianidin does not have adverse effects on bumblebee fecundity or learning ability. PMID:27014515

  11. Bifidobacteria in the digestive tract of bumblebees

    Czech Academy of Sciences Publication Activity Database

    Killer, Jiří; Kopečný, Jan; Mrázek, Jakub; Rada, V.; Dubá, S.; Marounek, Milan

    2010-01-01

    Roč. 16, č. 2 (2010), s. 165-170. ISSN 1075-9964 R&D Projects: GA ČR GD525/08/H060 Institutional research plan: CEZ:AV0Z50450515 Keywords : Bifidobacteria * Bumblebee * Digestive tract Subject RIV: GM - Food Processing Impact factor: 2.448, year: 2010

  12. Bumblebees exhibit the memory spacing effect

    Science.gov (United States)

    Toda, Nicholas R. T.; Song, Jeremy; Nieh, James C.

    2009-10-01

    Associative learning is key to how bees recognize and return to rewarding floral resources. It thus plays a major role in pollinator floral constancy and plant gene flow. Honeybees are the primary model for pollinator associative learning, but bumblebees play an important ecological role in a wider range of habitats, and their associative learning abilities are less well understood. We assayed learning with the proboscis extension reflex (PER), using a novel method for restraining bees (capsules) designed to improve bumblebee learning. We present the first results demonstrating that bumblebees exhibit the memory spacing effect. They improve their associative learning of odor and nectar reward by exhibiting increased memory acquisition, a component of long-term memory formation, when the time interval between rewarding trials is increased. Bombus impatiens forager memory acquisition (average discrimination index values) improved by 129% and 65% at inter-trial intervals (ITI) of 5 and 3 min, respectively, as compared to an ITI of 1 min. Memory acquisition rate also increased with increasing ITI. Encapsulation significantly increases olfactory memory acquisition. Ten times more foragers exhibited at least one PER response during training in capsules as compared to traditional PER harnesses. Thus, a novel conditioning assay, encapsulation, enabled us to improve bumblebee-learning acquisition and demonstrate that spaced learning results in better memory consolidation. Such spaced learning likely plays a role in forming long-term memories of rewarding floral resources.

  13. Neonicotinoids target distinct nicotinic acetylcholine receptors and neurons, leading to differential risks to bumblebees

    Science.gov (United States)

    Moffat, Christopher; Buckland, Stephen T.; Samson, Andrew J.; McArthur, Robin; Chamosa Pino, Victor; Bollan, Karen A.; Huang, Jeffrey T.-J.; Connolly, Christopher N.

    2016-04-01

    There is growing concern over the risk to bee populations from neonicotinoid insecticides and the long-term consequences of reduced numbers of insect pollinators to essential ecosystem services and food security. Our knowledge of the risk of neonicotinoids to bees is based on studies of imidacloprid and thiamethoxam and these findings are extrapolated to clothianidin based on its higher potency at nicotinic acetylcholine receptors. This study addresses the specificity and consequences of all three neonicotinoids to determine their relative risk to bumblebees at field-relevant levels (2.5 ppb). We find compound-specific effects at all levels (individual cells, bees and whole colonies in semi-field conditions). Imidacloprid and clothianidin display distinct, overlapping, abilities to stimulate Kenyon cells, indicating the potential to differentially influence bumblebee behavior. Bee immobility was induced only by imidacloprid, and an increased vulnerability to clothianidin toxicity only occurred following chronic exposure to clothianidin or thiamethoxam. At the whole colony level, only thiamethoxam altered the sex ratio (more males present) and only clothianidin increased queen production. Finally, both imidacloprid and thiamethoxam caused deficits in colony strength, while no detrimental effects of clothianidin were observed. Given these findings, neonicotinoid risk needs to be considered independently for each compound and target species.

  14. Bumblebee workers from different sire groups vary in susceptibility to parasite infection

    DEFF Research Database (Denmark)

    Baer, Boris; Schmid-Hempel, Paul

    2003-01-01

    is so far only supported indirectly. Here we tested this crucial assumption using data from a study on the bumblebee Bombus terrestris L. with queens inseminated with sperm of either one or several males that originated from different sire groups (i.e. groups of brothers). We found that, under field...... conditions, workers from different sire groups, forming a patriline within a given colony, indeed differ in their susceptibility to the common intestinal parasite, Crithidia bombi, and do so independently of queen mating frequency....

  15. Spatial reorientation by geometry in bumblebees.

    Directory of Open Access Journals (Sweden)

    Valeria Anna Sovrano

    Full Text Available Human and non-human animals are capable of using basic geometric information to reorient in an environment. Geometric information includes metric properties associated with spatial surfaces (e.g., short vs. long wall and left-right directionality or 'sense' (e.g. a long wall to the left of a short wall. However, it remains unclear whether geometric information is encoded by explicitly computing the layout of surface geometry or by matching images of the environment. View-based spatial encoding is generally thought to hold for insect navigation and, very recently, evidence for navigation by geometry has been reported in ants but only in a condition which does not allow the animals to use features located far from the goal. In this study we tested the spatial reorientation abilities of bumblebees (Bombus terrestris. After spatial disorientation, by passive rotation both clockwise and anticlockwise, bumblebees had to find one of the four exit holes located in the corners of a rectangular enclosure. Bumblebees systematically confused geometrically equivalent exit corners (i.e. corners with the same geometric arrangement of metric properties and sense, for example a short wall to the left of a long wall. However, when one wall of the enclosure was a different colour, bumblebees appeared to combine this featural information (either near or far from the goal with geometric information to find the correct exit corner. Our results show that bumblebees are able to use both geometric and featural information to reorient themselves, even when features are located far from the goal.

  16. Sensory Ecology of Foraging in Bumblebees

    OpenAIRE

    Spaethe, Johannes

    2002-01-01

    Pollinating insects exhibit a complex behavior while foraging for nectar and pollen. Many studies have focused on ultimate mechanisms of this behavior, however, the sensory-perceptual processes that constrain such behavior have rarely been considered. In the present study I used bumblebees (Bombus terrestris), an important pollinating insect, to investigate possible sensory constraints on foraging behavior. Additionally, I survey inter-individual variation in the sensory capabilities and beha...

  17. How floral odours are learned inside the bumblebee ( Bombus terrestris) nest

    Science.gov (United States)

    Molet, Mathieu; Chittka, Lars; Raine, Nigel E.

    2009-02-01

    Recruitment in social insects often involves not only inducing nestmates to leave the nest, but also communicating crucial information about finding profitable food sources. Although bumblebees transmit chemosensory information (floral scent), the transmission mechanism is unknown as mouth-to-mouth fluid transfer (as in honeybees) does not occur. Because recruiting bumblebees release a pheromone in the nest that triggers foraging in previously inactive workers, we tested whether this pheromone helps workers learn currently rewarding floral odours, as found in food social learning in rats. We exposed colonies to artificial recruitment pheromone, paired with anise scent. The pheromone did not facilitate learning of floral scent. However, we found that releasing floral scent in the air of the colony was sufficient to trigger learning and that learning performance was improved when the chemosensory cue was provided in the nectar in honeypots; probably because it guarantees a tighter link between scent and reward, and possibly because gustatory cues are involved in addition to olfaction. Scent learning was maximal when anise-scented nectar was brought into the nest by demonstrator foragers, suggesting that previously unidentified cues provided by successful foragers play an important role in nestmates learning new floral odours.

  18. Historical species losses in bumblebee evolution.

    Science.gov (United States)

    Condamine, Fabien L; Hines, Heather M

    2015-03-01

    Investigating how species coped with past environmental changes informs how modern species might face human-induced global changes, notably via the study of historical extinction, a dominant feature that has shaped current biodiversity patterns. The genus Bombus, which comprises 250 mostly cold-adapted species, is an iconic insect group sensitive to current global changes. Through a combination of habitat loss, pathogens and climate change, bumblebees have experienced major population declines, and several species are threatened with extinction. Using a time-calibrated tree of Bombus, we analyse their diversification dynamics and test hypotheses about the role of extinction during major environmental changes in their evolutionary history. These analyses support a history of fluctuating species dynamics with two periods of historical species loss in bumblebees. Dating estimates gauge that one of these events started after the middle Miocene climatic optimum and one during the early Pliocene. Both periods are coincident with global climate change that may have extirpated Bombus species. Interestingly, bumblebees experienced high diversification rates during the Plio-Pleistocene glaciations. We also found evidence for a major species loss in the past one million years that may be continuing today. PMID:25762572

  19. Effect of oral infection with Kashmir bee virus and Israeli acute paralysis virus on bumblebee (Bombus terrestris) reproductive success.

    Science.gov (United States)

    Meeus, Ivan; de Miranda, Joachim R; de Graaf, Dirk C; Wäckers, Felix; Smagghe, Guy

    2014-09-01

    Israeli acute paralysis virus (IAPV) together with Acute bee paralysis virus (ABPV) and Kashmir bee virus (KBV) constitute a complex of closely related dicistroviruses. They are infamous for their high mortality after injection in honeybees. These viruses have also been reported in non-Apis hymenopteran pollinators such as bumblebees, which got infected with IAPV when placed in the same greenhouse with IAPV infected honeybee hives. Here we orally infected Bombus terrestris workers with different doses of either IAPV or KBV viral particles. The success of the infection was established by analysis of the bumblebees after the impact studies: 50days after infection. Doses of 0.5×10(7) and 1×10(7) virus particles per bee were infectious over this period, for IAPV and KBV respectively, while a dose of 0.5×10(6) IAPV particles per bee was not infectious. The impact of virus infection was studied in micro-colonies consisting of 5 bumblebees, one of which becomes a pseudo-queen which proceeds to lay unfertilized (drone) eggs. The impact parameters studied were: the establishment of a laying pseudo-queen, the timing of egg-laying, the number of drones produced, the weight of these drones and worker mortality. In this setup KBV infection resulted in a significant slower colony startup and offspring production, while only the latter can be reported for IAPV. Neither virus increased worker mortality, at the oral doses used. We recommend further studies on how these viruses transmit between different pollinator species. It is also vital to understand how viral prevalence can affect wild bee populations because disturbance of the natural host-virus association may deteriorate the already critically endangered status of many bumblebee species. PMID:25004171

  20. How to know which food is good for you: bumblebees use taste to discriminate between different concentrations of food differing in nutrient content.

    Science.gov (United States)

    Ruedenauer, Fabian A; Spaethe, Johannes; Leonhardt, Sara D

    2015-07-01

    In view of the ongoing pollinator decline, the role of nutrition in bee health has received increasing attention. Bees obtain fat, carbohydrates and protein from pollen and nectar. As both excessive and deficient amounts of these macronutrients are detrimental, bees would benefit from assessing food quality to guarantee an optimal nutrient supply. While bees can detect sucrose and use it to assess nectar quality, it is unknown whether they can assess the macronutrient content of pollen. Previous studies have shown that bees preferentially collect pollen of higher protein content, suggesting that differences in pollen quality can be detected either by individual bees or via feedback from larvae. In this study, we examined whether and, if so, how individuals of the buff-tailed bumblebee (Bombus terrestris) discriminate between different concentrations of pollen and casein mixtures and thus nutrients. Bumblebees were trained using absolute and differential conditioning of the proboscis extension response (PER). As cues related to nutrient concentration could theoretically be perceived by either smell or taste, bees were tested on both olfactory and, for the first time, chemotactile perception. Using olfactory cues, bumblebees learned and discriminated between different pollen types and casein, but were unable to discriminate between different concentrations of these substances. However, when they touched the substances with their antennae, using chemotactile cues, they could also discriminate between different concentrations. Bumblebees are therefore able to discriminate between foods of different concentrations using contact chemosensory perception (taste). This ability may enable them to individually regulate the nutrient intake of their colonies. PMID:26202778

  1. Reduction of Bumblebee Noise Generated by GSM

    Directory of Open Access Journals (Sweden)

    Han Su Kyi

    2014-09-01

    Full Text Available This research work presents a method for reducing a bumblebee noise generated by a GSM system. Global smart phone penetration has been very swift and 2nd generation, 3rd generation and 4th generation communication technology are commercially used in the world. GSM technology uses a channel access method that combines frequency division multiple access (FDMA and time division multiple access (TDMA. There are four commercial frequency bands. GSM technology has a burst structure by a TDMA method. And hence, the GSM technology has a disadvantage; radiation noise is generated from an antenna propagation signal of the smart phone, and consequently, the voice quality of the smart phone is degraded. This noise is commonly known as bumblebee noise, buzz noise or TDMA noise. There have been several studies to reduce the noise since a release of GSM technology in a commercial market. Those studies mainly focused on designing infinite impulse response (IIR notch filters by the signal processing technology or on data burst transmission schemes.

  2. A conserved class of queen pheromones? Re-evaluating the evidence in bumblebees (Bombus impatiens).

    Science.gov (United States)

    Amsalem, Etya; Orlova, Margarita; Grozinger, Christina M

    2015-10-22

    The regulation of reproductive division of labour is a key component in the evolution of social insects. Chemical signals are important mechanisms to regulate worker reproduction, either as queen-produced pheromones that coercively inhibit worker reproduction or as queen signals that honestly advertise her fecundity. A recent study suggested that a conserved class of hydrocarbons serve as queen pheromones across three independent origins of eusociality. In bumblebees (Bombus terrestris), pentacosane (C25) was suggested to serve as a queen pheromone. Here, we repeat these studies using a different species of bumblebee (Bombus impatiens) with a more controlled experimental design. Instead of dequeened colonies, we used same-aged, three-worker queenless groups comprising either experienced or naive workers (with/without adult exposure to queen pheromone). We quantified three hydrocarbons (C23, C25 and C27) on the cuticular surfaces of females and tested their effects on the two worker types. Our results indicate differences in responses of naive and experienced workers, genetic effects on worker reproduction, and general effects of hydrocarbons and duration of egg laying on ovary resorption rates. However, we found no evidence to support the theory that a conserved class of hydrocarbons serve as queen pheromones or queen signals in Bombus impatiens. PMID:26490791

  3. Stabilization control of a bumblebee in hovering and forward flight

    Institute of Scientific and Technical Information of China (English)

    Yan Xiong; Mao Sun

    2009-01-01

    Our previous study shows that the hovering and forward flight of a bumblebee do not have inherent stabil-ity (passive stability). But the bumblebees are observed to fly stably. Stabilization control must have been applied. In this study, we investigate the longitudinal stabilization con-trol of the bumblebee. The method of computational fluid dynamics is used to compute the control derivatives and the techniques of eigenvalue and eigenvector analysis and modal decomposition are used for solving the equations of motion. Controllability analysis shows that at all flight speeds consid-ered, although inherently unstable, the flight is controllable. By feedbacking the state variables, i.e. vertical and horizon-tal velocities, pitching rate and pitch angle (which can be measured by the sensory system of the insect), to produce changes in stroke angle and angle of attack of the wings, the flight can be stabilized, explaining why the bumblebees can fly stably even if they are passively unstable.

  4. Analysis of triacylglycerols extracted from fat bodies of bumblebees

    Czech Academy of Sciences Publication Activity Database

    Kofroňová, Edita

    Praha : Institute of Chemical Technology , 2008. -. [Conference of Post-Graduate Students. 15.09.2008, Praha] Institutional research plan: CEZ:AV0Z40550506 Keywords : atmospheric pressure chemical ionization * bumblebees * tricylglycerols Subject RIV: CC - Organic Chemistry

  5. Flower Colour: How Bumblebees Handle Colours with Perceptually Changing Hues.

    Science.gov (United States)

    Lunau, Klaus

    2016-03-21

    Colours are floral signals enabling bees to detect, inspect and discriminate flowers in a multitasking world. Behavioural tests now show that trained bumblebees find iridescent coloured targets more quickly and that weak iridescence does not corrupt target identification. PMID:27003883

  6. Bombus cullumanus—an extinct European bumblebee species?

    OpenAIRE

    Williams, Paul; Byvaltsev, Alexandr; Sheffield, Cory; Rasmont, Pierre

    2013-01-01

    Bombus cullumanus s. str. has attracted some of the greatest conservation concerns among bumblebees in Europe because it might now be extinct. However, there has been long-standing disagreement about whether it is conspecific with other eastern pale-banded bumblebees. We investigate these relationships using new data from DNA (COI) barcodes. The results support a Nearctic rufocinctus-group (Bombus rufocinctus) and a Palaearctic cullumanus-group, the latter with just three species: Bombus seme...

  7. Fertility signals in the bumblebee Bombus terrestris (Hymenoptera: Apidae)

    Science.gov (United States)

    Sramkova, A.; Schulz, C.; Twele, R.; Francke, W.; Ayasse, M.

    2008-06-01

    In eusocial Hymenoptera, queen control over workers is probably inseparable from the mechanism of queen recognition. In primitively eusocial bumblebees ( Bombus), worker reproduction is controlled not only by the presence or absence of a dominant queen but also by other dominant workers. Furthermore, it was shown that the queen dominance is maintained by pheromonal cues. We investigated whether there is a similar odor signal released by egg-laying queens and workers that may have a function as a fertility signal. We collected cuticular surface extracts from nest-searching and breeding Bombus terrestris queens and workers that were characterized by their ovarian stages. In chemical analyses, we identified 61 compounds consisting of aldehydes, alkanes, alkenes, and fatty acid esters. Nest-searching queens and all groups of breeding females differed significantly in their odor bouquets. Furthermore, workers before the competition point (time point of colony development where workers start to develop ovaries and lay eggs) differed largely from queens and all other groups of workers. Breeding queens showed a unique bouquet of chemical compounds and certain queen-specific compounds, and the differences toward workers decrease with an increasing development of the workers’ ovaries, hinting the presence of a reliable fertility signal. Among the worker groups, the smallest differences were found after the competition point. Egg-laying females contained higher total amounts of chemical compounds and of relative proportions of wax-type esters and aldehydes than nest-searching queens and workers before the competition point. Therefore, these compounds may have a function as a fertility signal present in queens and workers.

  8. The genomes of two key bumblebee species with primitive eusocial organization

    DEFF Research Database (Denmark)

    Sadd, Ben M.; Barribeau, Seth M.; Bloch, Guy;

    2015-01-01

    BACKGROUND: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there ...

  9. Colonial today

    OpenAIRE

    Agarez, Ricardo; Beeckmans, Luce; Herbelin, Caroline; Lagae, Johan; Lee, Rachel; Matos, Madalena Cunha; Murray, Noëleen; van Roosmalen, Pauline K.M.; Volait, Mercedes

    2013-01-01

    Across the world, colonialism produced a substantial built legacy that in many cases continues to mark post-colonial urban landscapes. This theme issue addresses the ambivalences surrounding the position of colonial architecture as heritage in the present day, questioning the common assumption that architecture produced under colonial rule constitutes, by definition, a “dissonant heritage”. Presenting cases that highlight the myriad ways in which colonial architecture is re-used, re-appropria...

  10. Habitat and forage associations of a naturally colonising insect pollinator, the tree bumblebee Bombus hypnorum.

    Science.gov (United States)

    Crowther, Liam P; Hein, Pierre-Louis; Bourke, Andrew F G

    2014-01-01

    Bumblebees (Bombus species) are major pollinators of commercial crops and wildflowers but factors affecting their abundance, including causes of recent population declines, remain unclear. Investigating the ecology of species with expanding ranges provides a potentially powerful means of elucidating these factors. Such species may also bring novel pollination services to their new ranges. We therefore investigated landscape-scale habitat use and foraging preferences of the Tree Bumblebee, B. hypnorum, a recent natural colonist that has rapidly expanded its range in the UK over the past decade. Counts of B. hypnorum and six other Bombus species were made in March-June 2012 within a mixed landscape in south-eastern Norfolk, UK. The extent of different landscape elements around each transect was quantified at three scales (250 m, 500 m and 1500 m). We then identified the landscape elements that best predicted the density of B. hypnorum and other Bombus species. At the best fitting scale (250 m), B. hypnorum density was significantly positively associated with extent of both urban and woodland cover and significantly negatively associated with extent of oilseed rape cover. This combination of landscape predictors was unique to B. hypnorum. Urban and woodland cover were associated with B. hypnorum density at three and two, respectively, of the three scales studied. Relative to other Bombus species, B. hypnorum exhibited a significantly higher foraging preference for two flowering trees, Crataegus monogyna and Prunus spinosa, and significantly lower preferences for Brassica napus, Glechoma hederacea and Lamium album. Our study provides novel, quantitative support for an association of B. hypnorum with urban and woodland landscape elements. Range expansion in B. hypnorum appears to depend, on exploitation of widespread habitats underutilised by native Bombus species, suggesting B. hypnorum will readily co-exist with these species. These findings suggest that management

  11. Seasonal Dynamics in the Chemistry and Structure of the Fat Bodies of Bumblebee Queens.

    Directory of Open Access Journals (Sweden)

    Alena Votavová

    Full Text Available Insects' fat bodies are responsible for nutrient storage and for a significant part of intermediary metabolism. Thus, it can be expected that the structure and content of the fat body will adaptively change, if an insect is going through different life stages. Bumblebee queens belong to such insects as they dramatically change their physiology several times over their lives in relation to their solitary overwintering, independent colony foundation stage, and during the colony life-cycle ending in the senescent stage. Here, we report on changes in the ultrastructure and lipid composition of the peripheral fat body of Bombus terrestris queens in relation to seasonal changes in the queens' activity. Six life stages are defined and evaluated in particular: pharate, callow, before and after hibernation, egg-laying, and senescence. Transmission electron microscopy revealed that the fat body contained two main cell types-adipocytes and oenocytes. Only adipocytes reveal important changes related to the life phase, and mostly the ration between inclusion and cytoplasm volume varies among particular stages. Both electron microscopy and chemical analyses of lipids highlighted seasonal variability in the quantity of the stored lipids, which peaked prior to hibernation. Triacylglycerols appeared to be the main energy source during hibernation, while the amount of glycogen before and after hibernation remained unchanged. In addition, we observed that the representation of some fatty acids within the triacylglycerols change during the queen's life. Last but not least, we show that fat body cell membranes do not undergo substantial changes concerning phospholipid composition in relation to overwintering. This finding supports the hypothesis that the cold-adaptation strategy of bumblebee queens is more likely to be based on polyol accumulation than on the restructuring of lipid membranes.

  12. Does the queen win it all? Queen-worker conflict over male production in the bumblebee, Bombus terrestris

    Science.gov (United States)

    Alaux, Cédric; Savarit, Fabrice; Jaisson, Pierre; Hefetz, Abraham

    Social insects provide a useful model for studying the evolutionary balance between cooperation and conflict linked to genetic structure. We investigated the outcome of this conflict in the bumblebee, Bombus terrestris, whose annual colony life cycle is characterized by overt competition over male production. We established artificial colonies composed of a queen and unrelated workers by daily exchange of callow workers between colony pairs of distinct genetic make-up. Using microsatellite analysis, this procedure allowed an exact calculation of the proportion of worker-derived males. The development and social behavior of these artificial colonies were similar to those of normal colonies. Despite a high worker reproduction attempt (63.8% of workers had developed ovaries and 38.4% were egg-layers), we found that on average 95% of the males produced during the competition phase (CPh) were queen-derived. However, in four colonies, queen death resulted in a considerable amount of worker-derived male production. The different putative ultimate causes of this efficient control by the queen are discussed, and we suggest a possible scenario of an evolutionary arms race that may occur between these two female castes.

  13. Fibrin(ogen)olytic activity of bumblebee venom serine protease

    International Nuclear Information System (INIS)

    Bee venom is a rich source of pharmacologically active components; it has been used as an immunotherapy to treat bee venom hypersensitivity, and venom therapy has been applied as an alternative medicine. Here, we present evidence that the serine protease found in bumblebee venom exhibits fibrin(ogen)olytic activity. Compared to honeybee venom, bumblebee venom contains a higher content of serine protease, which is one of its major components. Venom serine proteases from bumblebees did not cross-react with antibodies against the honeybee venom serine protease. We provide functional evidence indicating that bumblebee (Bombus terrestris) venom serine protease (Bt-VSP) acts as a fibrin(ogen)olytic enzyme. Bt-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products. However, Bt-VSP is not a plasminogen activator, and its fibrinolytic activity is less than that of plasmin. Taken together, our results define roles for Bt-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings offer significant insight into the allergic reaction sequence that is initiated by bee venom serine protease and its potential usefulness as a clinical agent in the field of hemostasis and thrombosis. - Graphical abstract: Display Omitted Highlights: → Bumblebee venom serine protease (Bt-VSP) is a fibrin(ogen)olytic enzyme. → Bt-VSP activates prothrombin. → Bt-VSP directly degrades fibrinogen into fibrin degradation products. → Bt-VSP is a hemostatically active protein that is a potent clinical agent.

  14. The final moments of landing in bumblebees, Bombus terrestris.

    Science.gov (United States)

    Reber, Therese; Baird, Emily; Dacke, Marie

    2016-04-01

    In comparison to other insects, like honeybees, bumblebees are very effective pollinators. Even though landing is a crucial part of pollination, little is known about how bumblebees orchestrate the final, critical moments of landing. Here, we use high-speed recordings to capture the fine details of the landing behaviour of free-flying bumblebees (Bombus terrestris), while landing on a flat platform with different orientations. We find that the bees have a fairly constant body and head orientation at the moment of leg extension, irrespective of platform tilt. At the same moment in time, the distance to the platform is held constant at around 8 mm (with the exception of low platform tilts). The orientation of the antennae and the first appendage that touches the platform vary between platform orientations, while the duration of the hover phase does not. Overall, the final moments of landing in bumblebees and their close relatives, the honeybees, are similar. However, the distance to the platform at the moment of leg extension and the duration of the hover phase are different in bumblebees and honeybees, suggesting that they are primarily adapted to land on surfaces with different orientations. PMID:26868924

  15. Wing flexibility enhances load-lifting capacity in bumblebees.

    Science.gov (United States)

    Mountcastle, Andrew M; Combes, Stacey A

    2013-05-22

    The effect of wing flexibility on aerodynamic force production has emerged as a central question in insect flight research. However, physical and computational models have yielded conflicting results regarding whether wing deformations enhance or diminish flight forces. By experimentally stiffening the wings of live bumblebees, we demonstrate that wing flexibility affects aerodynamic force production in a natural behavioural context. Bumblebee wings were artificially stiffened in vivo by applying a micro-splint to a single flexible vein joint, and the bees were subjected to load-lifting tests. Bees with stiffened wings showed an 8.6 per cent reduction in maximum vertical aerodynamic force production, which cannot be accounted for by changes in gross wing kinematics, as stroke amplitude and flapping frequency were unchanged. Our results reveal that flexible wing design and the resulting passive deformations enhance vertical force production and load-lifting capacity in bumblebees, locomotory traits with important ecological implications. PMID:23536604

  16. Mechanosensory hairs in bumblebees (Bombus terrestris) detect weak electric fields.

    Science.gov (United States)

    Sutton, Gregory P; Clarke, Dominic; Morley, Erica L; Robert, Daniel

    2016-06-28

    Bumblebees (Bombus terrestris) use information from surrounding electric fields to make foraging decisions. Electroreception in air, a nonconductive medium, is a recently discovered sensory capacity of insects, yet the sensory mechanisms remain elusive. Here, we investigate two putative electric field sensors: antennae and mechanosensory hairs. Examining their mechanical and neural response, we show that electric fields cause deflections in both antennae and hairs. Hairs respond with a greater median velocity, displacement, and angular displacement than antennae. Extracellular recordings from the antennae do not show any electrophysiological correlates to these mechanical deflections. In contrast, hair deflections in response to an electric field elicited neural activity. Mechanical deflections of both hairs and antennae increase with the electric charge carried by the bumblebee. From this evidence, we conclude that sensory hairs are a site of electroreception in the bumblebee. PMID:27247399

  17. Spatio-temporal dynamics of bumblebees foraging under predation risk

    CERN Document Server

    Lenz, Friedrich; Chittka, Lars; Chechkin, Aleksei V; Klages, Rainer

    2011-01-01

    We study bumblebees searching for nectar in a laboratory experiment with and without different types of artificial spiders as predators. We find that the flight velocities obey mixed probability distributions reflecting the access to the food sources while the threat posed by the spiders shows up only in the velocity correlations. This means that the bumblebees adjust their flight patterns spatially to the environment and temporally to the predation risk. Key information on response to environmental changes is thus contained in temporal correlation functions and not in spatial distributions.

  18. Background complexity affects colour preference in bumblebees

    Science.gov (United States)

    Forrest, Jessica; Thomson, James D.

    2009-08-01

    Flowers adapted for hummingbird pollination are typically red. This correlation is usually explained by the assertion that nectar- or pollen-stealing bees are “blind” to red flowers. However, laboratory studies have shown that bees are capable of locating artificial red flowers and often show no innate preference for blue over red. We hypothesised that these findings might be artefacts of the simplified laboratory environment. Using bumblebees ( Bombus impatiens) that had been trained to visit red and blue artificial flowers, we tested whether colour preference was influenced by complexity of the background on which they were foraging. Many bees were indifferent to flower colour when tested using a uniform green background like those commonly used in laboratory studies, but all bees showed strong colour preferences (usually for blue) when flowers were presented against a photograph of real foliage. Overall, preference for blue flowers was significantly greater on the more realistic, complex background. These results support the notion that the red of “hummingbird syndrome” flowers can function to reduce bee visits despite the ability of bees to detect red and highlight the need to consider context when drawing inferences about pollinator preferences from laboratory data.

  19. Modality-specific attention in foraging bumblebees.

    Science.gov (United States)

    Nityananda, Vivek; Chittka, Lars

    2015-10-01

    Attentional demands can prevent humans and other animals from performing multiple tasks simultaneously. Some studies, however, show that tasks presented in different sensory modalities (e.g. visual and auditory) can be processed simultaneously. This suggests that, at least in these cases, attention might be modality-specific and divided differently between tasks when present in the same modality compared with different modalities. We investigated this possibility in bumblebees (Bombus terrestris) using a biologically relevant experimental set-up where they had to simultaneously choose more rewarding flowers and avoid simulated predatory attacks by robotic 'spiders'. We found that when the tasks had to be performed using visual cues alone, bees failed to perform both tasks simultaneously. However, when highly rewarding flowers were indicated by olfactory cues and predators were indicated by visual cues, bees managed to perform both tasks successfully. Our results thus provide evidence for modality-specific attention in foraging bees and establish a novel framework for future studies of crossmodal attention in ecologically realistic settings. PMID:26587245

  20. Spatial encoding by bumblebees (Bombus impatiens) of a reward within an artificial flower array.

    Science.gov (United States)

    Church, Dana L; Plowright, Catherine M S

    2006-04-01

    We presented bumblebees a spatial memory task similar to that used with other species (e.g., cats, dogs, and pigeons). In some conditions we allowed for presence of scent marks in addition to placing local and global spatial cues in conflict. Bumblebees (Bombus impatiens) were presented an array of artificial flowers within a flight cage, one flower offering reward (S+), while the others were empty (S-). Bees were tested with empty flowers. In Experiment 1, flowers were either moved at the time of testing or not. Bees returned to the flower in the same absolute position of the S+ (the flower-array-independent (FAI) position), even if it was in the wrong position relative to the S- and even when new flower covers prevented the use of possible scent marks. New flower covers (i.e., without possible scent marks) had the effect of lowering the frequency of probing behavior. In Experiment 2, the colony was moved between training and testing. Again, bees chose the flower in the FAI position of the S+, and not the flower that would be chosen using strictly memory for a flight vector. Together, these experiments show that to locate the S+ bees did not rely on scent marks nor the positions of the S-, though the S- were prominent objects close to the goal. Also, bees selected environmental features to remember the position of the S+ instead of relying upon a purely egocentric point of view. Similarities with honeybees and vertebrates are discussed, as well as possible encoding mechanisms. PMID:16416106

  1. Iron-based granules in body of bumblebees

    Czech Academy of Sciences Publication Activity Database

    Jandacka, P.; Kasparova, B.; Jirásková, Yvonna; Dedkova, K.; Mamulová-Kutláková, K.; Kukutschová, J.

    2015-01-01

    Roč. 28, č. 1 (2015), s. 89-99. ISSN 0966-0844 R&D Projects: GA ČR(CZ) GAP108/11/1350 Institutional support: RVO:68081723 Keywords : Magnetoreception * Bumblebee * Biomineralisation * Iron granules Subject RIV: BO - Biophysics Impact factor: 2.503, year: 2014

  2. The genomes of two key bumblebee species with primitive eusocial organization

    OpenAIRE

    Sadd, Ben M; Barribeau, Seth M.; Bloch, Guy; de Graaf, Dirk C; Dearden, Peter; Elsik, Christine G; Gadau, Jürgen; Grimmelikhuijzen, Cornelis J. P.; Hasselmann, Martin; Lozier, Jeffrey D; Robertson, Hugh M; Smagghe, Guy; Stolle, Eckart; Van Vaerenbergh, Matthias; Waterhouse, Robert M.

    2015-01-01

    The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats.

  3. The genomes of two key bumblebee species with primitive eusocial organization

    OpenAIRE

    Sadd, Ben M; Barribeau, Seth M.; Bloch, Guy; de Graaf, Dirk C; Dearden, Peter; Elsik, Christine G; Gadau, Jürgen; Grimmelikhuijzen, Cornelis J. P.; Hasselmann, Martin; Lozier, Jeffrey D; Robertson, Hugh M; Smagghe, Guy; Stolle, Eckart; Van Vaerenbergh, Matthias; Waterhouse, Robert M.

    2015-01-01

    Background The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viabilit...

  4. The genomes of two key bumblebee species with primitive eusocial organization

    OpenAIRE

    Sadd, Ben M; Barribeau, Seth M.; Bloch, Guy; de Graaf, Dirk C; Dearden, Peter; Elsik, Christine G; Gadau, Jürgen; Grimmelikhuijzen, Cornelis; Hasselmann, Martin; Lozier, Jeffrey D; Robertson, Hugh M; Smagghe, Guy; Stolle, Eckart; Van Vaerenbergh, Matthias; Waterhouse, Robert M.

    2015-01-01

    BACKGROUND: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viabili...

  5. The genomes of two key bumblebee species with primitive eusocial organization

    OpenAIRE

    Sadd, Ben M; Barribeau, Seth M.; Bloch, Guy; de Graaf, Dirk C; Dearden, Peter; Elsik, Christine G; Gadau, Jürgen; Grimmelikhuijzen, Cornelis Jp; Hasselmann, Martin; Lozier, Jeffrey D; Robertson, Hugh M; Smagghe, Guy; Stolle, Eckart; Van Vaerenbergh, Matthias; Waterhouse, Robert M.

    2015-01-01

    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viabili...

  6. The genomes of two key bumblebee species with primitive eusocial organization

    OpenAIRE

    Sadd, Ben M; Barribeau, Seth M.; Bloch, Guy; de Graaf, Dirk C; Dearden, Peter; Elsik, Christine G; Gadau, Jürgen; Grimmelikhuijzen, Cornelis J. P.; Hasselmann, Martin; Lozier, Jeffrey D; Robertson, Hugh M; Smagghe, Guy; Stolle, Eckart; Van Vaerenbergh, Matthias; Waterhouse, Robert M.

    2015-01-01

    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated popula...

  7. Effectiveness of native bumblebees as pollinators of the alien invasive plant Impatiens glandulifera (Balsaminaceae) in Ireland

    OpenAIRE

    Stout, Jane C.; Caroline M. Nienhuis

    2009-01-01

    Flowers of alien invasive plants can be pollen limited due to a lack of effective pollinators. The alien Impatiens glandulifera is predominantly visited by bumblebees in its invaded range. There bumblebees pollinate I. glandulifera, but it remains unclear whether foraging behaviour or bumblebee or flower morphology affects effectiveness. We investigated the effectiveness of native bumblebee (Bombus pascuorum) pollinators in Ireland by quantifying pollen deposition and...

  8. Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees.

    Directory of Open Access Journals (Sweden)

    Paul H Williams

    Full Text Available Our grasp of biodiversity is fine-tuned through the process of revisionary taxonomy. If species do exist in nature and can be discovered with available techniques, then we expect these revisions to converge on broadly shared interpretations of species. But for the primarily arctic bumblebees of the subgenus Alpinobombus of the genus Bombus, revisions by some of the most experienced specialists are unusual for bumblebees in that they have all reached different conclusions on the number of species present. Recent revisions based on skeletal morphology have concluded that there are from four to six species, while variation in colour pattern of the hair raised questions as to whether at least seven species might be present. Even more species are supported if we accept the recent move away from viewing species as morphotypes to viewing them instead as evolutionarily independent lineages (EILs using data from genes. EILs are recognised here in practice from the gene coalescents that provide direct evidence for their evolutionary independence. We show from fitting both general mixed Yule/coalescent (GMYC models and Poisson-tree-process (PTP models to data for the mitochondrial COI gene that there is support for nine species in the subgenus Alpinobombus. Examination of the more slowly evolving nuclear PEPCK gene shows further support for a previously unrecognised taxon as a new species in northwestern North America. The three pairs of the most morphologically similar sister species are separated allopatrically and prevented from interbreeding by oceans. We also find that most of the species show multiple shared colour patterns, giving the appearance of mimicry among parts of the different species. However, reconstructing ancestral colour-pattern states shows that speciation is likely to have cut across widespread ancestral polymorphisms, without or largely without convergence. In the particular case of Alpinobombus, morphological, colour-pattern, and

  9. Regulation of Isoprenoid Pheromone Biosynthesis in Bumblebee Males.

    Science.gov (United States)

    Prchalová, Darina; Buček, Aleš; Brabcová, Jana; Žáček, Petr; Kindl, Jiří; Valterová, Irena; Pichová, Iva

    2016-02-01

    Males of the closely related species Bombus terrestris and Bombus lucorum attract conspecific females by completely different marking pheromones. MP of B. terrestris and B. lucorum pheromones contain mainly isoprenoid (ISP) compounds and fatty acid derivatives, respectively. Here, we studied the regulation of ISP biosynthesis in both bumblebees. RNA-seq and qRT-PCR analyses indicated that acetoacetyl-CoA thiolase (AACT), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), and farnesyl diphosphate synthase (FPPS) transcripts are abundant in the B. terrestris labial gland. Maximal abundance of these transcripts correlated well with AACT enzymatic activity detected in the LG extracts. In contrast, transcript abundances of AACT, HMGR, and FPPS in B. lucorum were low, and AACT activity was not detected in LGs. These results suggest that transcriptional regulation plays a key role in the control of ISP biosynthetic gene expression and ISP pheromone biosynthesis in bumblebee males. PMID:26632352

  10. Dynamic flight stability of a bumblebee in forward flight

    Institute of Scientific and Technical Information of China (English)

    Yan Xiong; Mao Sun

    2008-01-01

    The longitudinal dynamic flight stability of a bumblebee in forward flight is studied.The method of computational fluid dynamics is used to compute the aerodynamic derivatives and the techniques of eigenvalue and eigenvector analysis are employed for solving the equations of motion.The primary findings are as the following.The forward flight of the bumblebee is not dynamically stable due to the existence of one(or two)unstable or approximately neutrally stable natural modes of motion.At hovering to medium flight speed[flight speed ue=(0-3.5)m s-1;advance ratio J=0-0.44],the flight is weakly unstable or approximately neutrally stable;at high speed(ue=4.5 m s-1;J=0.57),the flight becomes strongly unstable(initial disturbance double its value in only 3.5 wingbeats).

  11. Bumblebee flight performance in environments of different proximity.

    Science.gov (United States)

    Linander, Nellie; Baird, Emily; Dacke, Marie

    2016-02-01

    Flying animals are capable of navigating through environments of different complexity with high precision. To control their flight when negotiating narrow tunnels, bees and birds use the magnitude of apparent image motion (known as optic flow) generated by the walls. In their natural habitat, however, these animals would encounter both cluttered and open environments. Here, we investigate how large changes in the proximity of nearby surfaces affect optic flow-based flight control strategies. We trained bumblebees to fly along a flight and recorded how the distance between the walls--from 60 cm to 240 cm--affected their flight control. Our results reveal that, as tunnel width increases, both lateral position and ground speed become increasingly variable. We also find that optic flow information from the ground has an increasing influence on flight control, suggesting that bumblebees measure optic flow flexibly over a large lateral and ventral field of view, depending on where the highest magnitude of optic flow occurs. A consequence of this strategy is that, when flying in narrow spaces, bumblebees use optic flow information from the nearby obstacles to control flight, while in more open spaces they rely primarily on optic flow cues from the ground. PMID:26614094

  12. Visual choice behavior by bumblebees (Bombus impatiens) confirms unsupervised neural network's predictions.

    Science.gov (United States)

    Orbán, Levente L; Plowright, Catherine M S; Chartier, Sylvain; Thompson, Emma; Xu, Vicki

    2015-08-01

    The behavioral experiment herein tests the computational load hypothesis generated by an unsupervised neural network to examine bumblebee (Bombus impatiens) behavior at 2 visual properties: spatial frequency and symmetry. Untrained "flower-naïve" bumblebees were hypothesized to prefer symmetry only when the spatial frequency of artificial flowers is high and therefore places great information-processing demands on the bumblebees' visual system. Bumblebee choice behavior was recorded using high-definition motion-sensitive camcorders. The results support the computational model's prediction: 1-axis symmetry influenced bumblebees' preference behavior at low and high spatial frequency patterns. Additionally, increasing the level of symmetry from 1 axis to 4 axes amplified preference toward the symmetric patterns of both low and high spatial frequency patterns. The results are discussed in the context of the artificial neural network model and other hypotheses generated from the behavioral literature. PMID:25984936

  13. The effect of olfactory exposure to non-insecticidal agrochemicals on bumblebee foraging behavior.

    Directory of Open Access Journals (Sweden)

    Jordanna D H Sprayberry

    Full Text Available Declines in bumblebee populations have led to investigations into potential causes - including agrochemical effects on bumblebee physiology. The indirect effects of agrochemicals (i.e. behavior modulation have been postulated, but rarely directly tested. Olfactory information is critical in mediating bumblebee-floral interactions. As agrochemicals emit volatiles, they may indirectly modify foraging behavior. We tested the effects of olfactory contamination of floral odor by agrochemical scent on foraging activity of Bombus impatiens using two behavioral paradigms: localization of food within a maze and forced-choice preference. The presence of a fungicide decreased bumblebees' ability to locate food within a maze. Additionally, bumblebees preferred to forage in non-contaminated feeding chambers when offered a choice between control and either fertilizer- or fungicide-scented chambers.

  14. GPU-Accelerated PIC/MCC Simulation of Laser-Plasma Interaction Using BUMBLEBEE

    Science.gov (United States)

    Jin, Xiaolin; Huang, Tao; Chen, Wenlong; Wu, Huidong; Tang, Maowen; Li, Bin

    2015-11-01

    The research of laser-plasma interaction in its wide applications relies on the use of advanced numerical simulation tools to achieve high performance operation while reducing computational time and cost. BUMBLEBEE has been developed to be a fast simulation tool used in the research of laser-plasma interactions. BUMBLEBEE uses a 1D3V electromagnetic PIC/MCC algorithm that is accelerated by using high performance Graphics Processing Unit (GPU) hardware. BUMBLEBEE includes a friendly user-interface module and four physics simulators. The user-interface provides a powerful solid-modeling front end and graphical and computational post processing functionality. The solver of BUMBLEBEE has four modules for now, which are used to simulate the field ionization, electron collisional ionization, binary coulomb collision and laser-plasma interaction processes. The ionization characteristics of laser-neutral interaction and the generation of high-energy electrons have been analyzed by using BUMBLEBEE for validation.

  15. Interspecific mating of the introduced bumblebee Bombus terrestris and the native Japanese bumblebee Bombus hypocrita sapporoensis results in inviable hybrids

    Science.gov (United States)

    Kanbe, Yuya; Okada, Ikuko; Yoneda, Masahiro; Goka, Koichi; Tsuchida, Koji

    2008-10-01

    The bumblebee Bombus terrestris is not only an effective pollinator, but also a potential invasive alien species outside its native range. Recently, nearly 30% of queens of the Japanese native species Bombus hypocrita sapporoensis and B. hypocrita hypocrita were estimated to copulate with B. terrestris males in the field, suggesting that indigenous bumblebees could be genetically deteriorated through hybrid production with the introduced species. In this study, we evaluated hybrid production between the introduced B. terrestris and the indigenous B. hypocrita sapporoensis under laboratory conditions. The hatching rate of eggs derived from interspecific matings was 0% and 8.6% depending on the direction of the cross, which was significantly lower than that from intraspecific matings of B. terrestris (76.9%) and B. hypocrita sapporoensis (78.9%). Genetic studies using microsatellite markers revealed that both haploid and diploid individuals were present in the egg stage, whereas all hatched larvae were haploid. In addition, histological studies revealed that eggs derived from interspecific matings terminated development 2 days after oviposition. These results strongly suggested that eggs derived from interspecific matings are inviable due to post-mating isolation mechanisms. Mass release of exotic pollinators could cause serious population declines of native bumblebee species.

  16. Targeted agri-environment schemes significantly improve the population size of common farmland bumblebee species.

    Science.gov (United States)

    Wood, Thomas J; Holland, John M; Hughes, William O H; Goulson, Dave

    2015-04-01

    Changes in agricultural practice across Europe and North America have been associated with range contractions and local extinction of bumblebees (Bombus spp.). A number of agri-environment schemes have been implemented to halt and reverse these declines, predominantly revolving around the provision of additional forage plants. Although it has been demonstrated that these schemes can attract substantial numbers of foraging bumblebees, it remains unclear to what extent they actually increase bumblebee populations. We used standardized transect walks and molecular techniques to compare the size of bumblebee populations between Higher Level Stewardship (HLS) farms implementing pollinator-friendly schemes and Entry Level Stewardship (ELS) control farms. Bumblebee abundance on the transect walks was significantly higher on HLS farms than ELS farms. Molecular analysis suggested maximum foraging ranges of 566 m for Bombus hortorum, 714 m for B. lapidarius, 363 m for B. pascuorum and 799 m for B. terrestris. Substantial differences in maximum foraging range were found within bumblebee species between farm types. Accounting for foraging range differences, B. hortorum (47 vs 13 nests/km(2) ) and B. lapidarius (45 vs 22 nests/km(2) ) were found to nest at significantly greater densities on HLS farms than ELS farms. There were no significant differences between farm type for B. terrestris (88 vs 38 nests/km(2) ) and B. pascuorum (32 vs 39 nests/km(2) ). Across all bumblebee species, HLS management had a significantly positive effect on bumblebee nest density. These results show that targeted agri-environment schemes that increase the availability of suitable forage can significantly increase the size of wild bumblebee populations. PMID:25753513

  17. The potential importance of synanthropic vegetation to bumblebees in urban ecosystems on the example of Lublin

    Directory of Open Access Journals (Sweden)

    Magdalena Lubiarz

    2014-01-01

    Full Text Available This study was an attempt to show synanthropic phytocoenoses of the city of Lublin which are potentially valuable to pollinating insects such as bumblebees. B. terrestris and B. lapidarius as well as B. lucorum, B. hypnorum and B. pascuorum were found to occur in Lublin. Artemisio-Tanacetetum, Bunietum orientalis, and Berteroëtum incanae were shown to be most valuable to bumblebees due to a high number of polleniferous and nectariferous species in these communities. The present study also allowed us to determine that the size of communities and their occurrence in a mosaic with parks and green spaces had an effect on the distribution of bumblebees.

  18. Effect of ultraviolet radiation absorbing film on pollination work of foreign bumblebee [Bombus terrestris

    International Nuclear Information System (INIS)

    The transmitted light through the ultraviolet radiation absorbing (UVA) film has a preventing effect of disease and pest occurrence. To develop the agriculture harmonized with the ecosystem, we attempted to research a further possible utilization of the UVA film. Pollination work of foreign bumblebee (Bombus terrestris) in the greenhouses roofed with UVA film and with common film for agriculture was examined in growing fruit-vegetables. The bumblebees used were not acclimatized to environmental conditions of the greenhouses. They visited flowers and gathered pollen from flowered crops grown in both houses, irrespective of the kind of film covering over the greenhouse roof, and the pollen quantity gathered was far greater in crops which produced in large quantity of pollen. Thus, the bumblebees were capable to work under the condition lacking in ultraviolet radiation. This pollinating behavior is different from that of honeybees. Then we concluded that bumblebees functioned well as an efficient pollinator under the condition without ultraviolet radiation

  19. Methods for species delimitation in bumblebees (Hymenoptera, Apidae, Bombus): towards an integrative approach

    Czech Academy of Sciences Publication Activity Database

    Lecocq, T.; Dellicour, S.; Michez, D.; Dehon, M.; Dewulf, A.; De Meulemeester, T.; Brasero, N.; Valterová, Irena; Rasplus, J. Y.; Rasmont, P.

    2015-01-01

    Roč. 44, č. 3 (2015), s. 281-297. ISSN 0300-3256 Institutional support: RVO:61388963 Keywords : bumblebee taxonomy * genetic analysis * pheromone composition Subject RIV: CC - Organic Chemistry Impact factor: 3.224, year: 2014

  20. Insect vision models under scrutiny: what bumblebees ( Bombus terrestris terrestris L.) can still tell us

    Science.gov (United States)

    Telles, Francismeire Jane; Rodríguez-Gironés, Miguel A.

    2015-02-01

    Three contending models address the ability of bees to detect and discriminate colours: the colour opponent coding (COC) model, the colour hexagon (CH) model and the receptor noise-limited (RN) model, but few studies attempt to determine which model fits experimental data best. To assess whether the models provide an accurate description of bumblebee colour space, we trained bees to discriminate four colour pairs. The perceptual distance between the colours of each pair was similar according to the CH model but varied widely according to the COC and RN models. The time that bees required to select a flower and the proportion of correct choices differed between groups: decision times decreased as achromatic contrast increased, and the proportion of correct choices increased with achromatic contrast and perceptual distance, as predicted by the COC and RN models. These results suggest that both chromatic and achromatic contrasts affected the discriminability of colour pairs. Since flower colour affects the foraging choices of bees and foraging choices affect the reproductive success of plants, a better understanding of which model is more accurate under each circumstance is required to predict bee behaviour and the ecological implications of flower choice and colour.

  1. Review of the methods to determine the hazard and toxicity of pesticides to bumblebees

    OpenAIRE

    Steen, van der, J.J.M.

    2001-01-01

    Methods to determine the impact of pesticides on bumblebees are described. They are classified into laboratory tests to determine the acute toxicity and the hazard to bumblebees, (semi) field tests, and brood tests. The reproducibility and the significance of the data for practical purpose are discussed. Standardized laboratory toxicity tests supply reproducible data. In hazard tests, both in the laboratory and semi field tests, the exposure is not proportionate to the number of adult insects...

  2. Crop flower visitation by honeybees, bumblebees and solitary bees: behavioural differences and diversity responses to landscape

    OpenAIRE

    Woodcock, B. A.; Edwards, M.; Redhead, J; Meak, W.R.; Nuttall, P; Falk, S; Nowakowski, M.; Pywell, R.F.

    2013-01-01

    In Europe, oilseed rape is the principal crop used in the production of edible and renewable fuel oil products. Insect pollinators, in particular bees, have been shown to have a positive effect on the seed set of this crop. We undertook experiments looking at behavioural differences between honeybees, bumblebees and solitary bees visiting oilseed rape flowers, and related this to landscape scale responses in visitation rates. We found that behavioural differences between honeybees, bumblebees...

  3. Study of the acarofauna of native bumblebee species (Bombus) from Argentina

    OpenAIRE

    Maggi, Matias; Lucia, Mariano; Abrahamovich,Alberto

    2011-01-01

    A total of 382 bumblebee specimens were examined: Bombus atratus (n = 310), Bombus morio (n = 42), Bombus bellicosus (n = 16), Bombus opifex (n = 8), and Bombus tucumanus (n = 6). Prevalence, abundance, and intensity of mite infestation for each Bombus species and for each caste were recorded. The different mite species infesting bumblebee specimens were: Kuzinia laevis (Dujardin), Kuzinia americana (Delfinado and Baker), Scutacarus acarorum (Goeze), Pneumolaelaps longanalis (Hunter and Husba...

  4. Patterns of genetic and reproductive traits differentiation in Mainland vs. Corsican populations of bumblebees.

    Directory of Open Access Journals (Sweden)

    Thomas Lecocq

    Full Text Available Populations on islands often exhibit lower levels of genetic variation and ecomorphological divergence compared to their mainland relatives. While phenotypic differentiation in characters, such as size or shape among insular organisms, has been well studied, insular differentiation in quantitative reproductive traits involved in chemical communication has received very little attention to date. Here, we investigated the impact of insularity on two syntopic bumblebee species pairs: one including species that are phylogenetically related (Bombus terrestris and B. lucorum, and the other including species that interact ecologically (B. terrestris and its specific nest inquiline B. vestalis. For each bumblebee species, we characterized the patterns of variation and differentiation of insular (Corsican vs. mainland (European populations (i with four genes (nuclear and mitochondrial, 3781 bp and (ii in the chemical composition of male marking secretions (MMS, a key trait for mate attraction in bumblebees, by gas chromatography-mass spectrometry (GC-MS. Our results provide evidence for genetic differentiation in Corsican bumblebees and show that, contrary to theoretical expectations, island populations of bumblebees exhibit levels of genetic variation similar to the mainland populations. Likewise, our comparative chemical analyses of MMS indicate that Corsican populations of bumblebees are significantly differentiated from the mainland yet they hold comparative levels of within-population MMS variability compared to the mainland. Therefore, insularity has led Corsican populations to diverge both genetically and chemically from their mainland relatives, presumably through genetic drift, but without a decrease of genetic diversity in island populations. We hypothesize that MMS divergence in Corsican bumblebees was driven by a persistent lack of gene flow with mainland populations and reinforced by the preference of Corsican females for sympatric (Corsican

  5. The pollination potential of free-foraging bumblebee (Bombus spp.) males (Hymenoptera: Apidae)

    OpenAIRE

    Wolf, Stephan; Moritz, Robin

    2014-01-01

    Bumblebee workers are efficient pollinators. However, despite their flower visits and less intense grooming the role of males as pollen vectors is largely unexplored. We compared the quantity and diversity of pollen on the bodies (pollination-active pollen) of free-foraging workers and males of two bumblebee species (Bombus lapidarius and Bombus terrestris) to assess their pollination potential. In both species, males exhibit worker-like flower constancy, but differ significantly from workers...

  6. Genetic Variability of the Neogregarine Apicystis bombi, an Etiological Agent of an Emergent Bumblebee Disease

    OpenAIRE

    Maharramov, Jafar; Meeus, Ivan; Maebe, Kevin; Arbetman, Marina; Morales, Carolina; Graystock, Peter; Hughes, William O. H.; Plischuk, Santiago; Carlos E. Lange; de Graaf, Dirk C.; Zapata, Nelson; de la Rosa, Jose Javier Perez; Murray, Tomás E; Brown, Mark J.F.; Smagghe, Guy

    2013-01-01

    The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera) and bumblebee species (Bombus terrestris and Bombus ruderatus) in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii). In this study we invest...

  7. Genetic variability of the neogregarine apicystis bombi, an etiological agent of an emergent bumblebee disease

    OpenAIRE

    Wicker-Thomas, Claude; Maharramov, Jafar; Meeus, Ivan; Maebe, Kevin; Arbetman, Marina; Morales, Carolina; Graystock, Peter; Hughes, William; Plischuk, Santiago; Carlos E. Lange; de Graaf, Dirk C; Zapata, Nelson; de la Rosa, Jose Javier Perez; Murray, Tomás E; Brown, Mark J F

    2013-01-01

    The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera) and bumblebee species (Bombus terrestris and Bombus ruderatus) in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii). In this study we invest...

  8. Genetic variability of the neogregarine Apicystis bombi, an etiological agent of an emergent bumblebee disease

    OpenAIRE

    Maharramov, Jafar; Meeus, Ivan; Maebe, Kevin; Arbetman, Marina; Morales, Carolina; Graystock, Peter; Hughes, William OH; Plischuk, Santiago; Carlos E. Lange; de Graaf, Dirk; Zapata, Nelson; Perez de la Rosa, Jose Javier; Murray, Tomás E; Brown, Mark JF; Smagghe, Guy

    2013-01-01

    The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera) and bumblebee species (Bombus terrestris and Bombus ruderatus) in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii). In this study we invest...

  9. Habitat and Forage Associations of a Naturally Colonising Insect Pollinator, the Tree Bumblebee Bombus hypnorum

    OpenAIRE

    Crowther, Liam P.; Hein, Pierre-Louis; Bourke, Andrew F.G.

    2014-01-01

    Bumblebees (Bombus species) are major pollinators of commercial crops and wildflowers but factors affecting their abundance, including causes of recent population declines, remain unclear. Investigating the ecology of species with expanding ranges provides a potentially powerful means of elucidating these factors. Such species may also bring novel pollination services to their new ranges. We therefore investigated landscape-scale habitat use and foraging preferences of the Tree Bumblebee, B. ...

  10. High prevalence and infection levels of Nosema ceranae in bumblebees Bombus atratus and Bombus bellicosus from Uruguay.

    Science.gov (United States)

    Arbulo, N; Antúnez, K; Salvarrey, S; Santos, E; Branchiccela, B; Martín-Hernández, R; Higes, M; Invernizzi, C

    2015-09-01

    Nosema ceranae is one of the most prevalent pathogens in Apis mellifera and has recently been found in multiple host species including several species of bumblebees. Prevalence and infection intensity of N. ceranae was determined in two species of native bumblebees from Uruguay. Nosema ceranae was the only microsporidia identified and mean prevalence was 72% in Bombus atratus and 63% in Bombus bellicosus, values much higher than those reported elsewhere. The presence of this pathogen in bumblebees may be threatening not only for bumblebee populations, but also to the rest of the native pollinator community and to honeybees. PMID:26248064

  11. Constructing a Stochastic Model of Bumblebee Flights from Experimental Data

    CERN Document Server

    Lenz, Friedrich; Klages, Rainer

    2013-01-01

    The movement of organisms is subject to a multitude of influences of widely varying character: from the bio-mechanics of the individual, over the interaction with the complex environment many animals live in, to evolutionary pressure and energy constraints. As the number of factors is large, it is very hard to build comprehensive movement models. Even when movement patterns in simple environments are analysed, the organisms can display very complex behaviours. While for largely undirected motion or long observation times the dynamics can sometimes be described by isotropic random walks, usually the directional persistence due to a preference to move forward has to be accounted for, e.g., by a correlated random walk. In this paper we generalise these descriptions to a model in terms of stochastic differential equations of Langevin type, which we use to analyse experimental search flight data of foraging bumblebees. Using parameter estimates we discuss the differences and similarities to correlated random walks...

  12. Climatic Risk and Distribution Atlas of European Bumblebees

    Directory of Open Access Journals (Sweden)

    Pierre Rasmont

    2015-02-01

    Full Text Available Bumble bees represent one of the most important groups of pollinators. In addition to their ecological and economic relevance, they are also a highly charismatic group which can help to increase the interest of people in realizing, enjoying and conserving natural systems. However, like most animals, bum- ble bees are sensitive to climate. In this atlas, maps depicting potential risks of climate change for bumble bees are shown together with informative summary statistics, ecological back- ground information and a picture of each European species. Thanks to the EU FP7 project STEP, the authors gathered over one million bumblebee records from all over Europe. Based on these data, they modelled the current climatic niche for almost all European species (56 species and projected future climatically suitable conditions using three climate change scenarios for the years 2050 and 2100. While under a moderate change scenario only 3 species are projected to be at the verge of extinction by 2100, 14 species are at high risk under an intermediate change scenario. Under a most severe change scenario as many as 25 species are projected to lose almost all of their climatically suitable area, while a total of 53 species (77% of the 69 European species would lose the main part of their suitable area. Climatic risks for bumblebees can be extremely high, depending on the future development of human society, and the corresponding effects on the climate. Strong mitigation strategies are needed to preserve this important species group and to ensure the sustainable provision of pollination services, to which they considerably contribute.

  13. Potential increase in mating frequency of queens in feral colonies of Bombus terrestris introduced into Japan

    Science.gov (United States)

    Inoue, Maki N.; Saito, Fuki; Tsuchida, Koji; Goka, Koichi

    2012-10-01

    With the exception of several species, bumblebees are monandrous. We examined mating frequency in feral colonies of the introduced bumblebee Bombus terrestris in Japan . Using microsatellite markers, genotyping of sperm DNA stored in the spermatheca of nine queens detected multiple insemination paternities in one queen; the others were singly mated. The average effective paternity frequency estimated from the genotypes of queens and workers was 1.23; that estimated from the workers' genotype alone was 2.12. These values were greater than those of laboratory-reared colonies in the native ranges of B. terrestris. The genotypes of one or two workers did not match those of their queens or showed paternities different from those of their nestmates; this may have arisen from either queen takeover or drifting of workers. These alien workers were responsible for the heterogeneous genotype distribution within each B. terrestris colony, resulting in higher estimates of paternity frequency than of insemination frequency. The high mating frequency of introduced B. terrestris may have occurred by artificial selection through mass breeding for commercialization. Moreover, polyandrous queens may be selectively advantageous, because reproduction by such queens is less likely to be disturbed by interspecific mating than that by monandrous queens.

  14. Conditional discrimination and response chains by worker bumblebees (Bombus impatiens Cresson, Hymenoptera: Apidae).

    Science.gov (United States)

    Mirwan, Hamida B; Kevan, Peter G

    2015-09-01

    We trained worker bumblebees to discriminate arrays of artificial nectaries (one, two, and three microcentrifuge tubes inserted into artificial flowers) from which they could forage in association with their location in a three-compartmental maze. Additionally, we challenged bees to learn to accomplish three different tasks in a fixed sequence during foraging. To enter the main three-compartmented foraging arena, they had first to slide open doors in an entry box to be able to proceed to an artificial flower patch in the main arena where they had to lift covers to the artificial nectaries from which they then fed. Then, the bees had to return to the entrance way to their hive, but to actually enter, were challenged to rotate a vertically oriented disc to expose the entry hole. The bees were adept at associating the array of nectaries with their position in the compartmental maze (one nectary in compartment one, two in two, and three in three), taking about six trials to arrive at almost error-free foraging. Over all it took the bees three days of shaping to become more or less error free at the multi-step suite of sequential task performances. Thus, they had learned where they were in the chain sequence, which array and in which compartment was rewarding, how to get to the rewarding array in the appropriate compartment, and finally how to return as directly as possible to their hive entrance, open the entrance, and re-enter the hive. Our experiments were not designed to determine the specific nature of the cues the bees used, but our results strongly suggest that the tested bees developed a sense of subgoals that needed to be achieved by recognizing the array of elements in a pattern and possibly chain learning in order to achieve the ultimate goal of successfully foraging and returning to their colony. Our results also indicate that the bees had organized their learning by a hierarchy as evidenced by their proceeding to completion of the ultimate goal without

  15. Quantitative historical change in bumblebee (Bombus spp. assemblages of red clover fields.

    Directory of Open Access Journals (Sweden)

    Yoko L Dupont

    Full Text Available BACKGROUND: Flower visiting insects provide a vitally important pollination service for many crops and wild plants. Recent decline of pollinating insects due to anthropogenic modification of habitats and climate, in particular from 1950's onwards, is a major and widespread concern. However, few studies document the extent of declines in species diversity, and no studies have previously quantified local abundance declines. We here make a quantitative assessment of recent historical changes in bumblebee assemblages by comparing contemporary and historical survey data. METHODOLOGY/PRINCIPAL FINDINGS: We take advantage of detailed, quantitative historical survey data from the 1930's on bumblebee (Bombus spp. abundances and species composition in red clover (Trifolium pratense fields, an important floral resource and an attractant of all bumblebee species. We used the historical survey data as a pre-industrialization baseline, and repeated the same sampling protocol at nearly the same localities at present, hence setting up a historical experiment. We detected historical changes in abundances (bees/m(2 of both workers (the "pollinatory units" and queens (effective population size, in addition to species composition. In particular, long-tongued bumblebee species showed consistent and dramatic declines in species richness and abundances throughout the flowering season of red clover, while short-tongued species were largely unaffected. Of 12 Bombus species observed in the 1930's, five species were not observed at present. The latter were all long-tongued, late-emerging species. CONCLUSIONS/SIGNIFICANCE: Because bumblebees are important pollinators, historical changes in local bumblebee assemblages are expected to severely affect plant reproduction, in particular long-tubed species, which are pollinated by long-tongued bumblebees.

  16. Ant colony for TSP

    OpenAIRE

    Feng, Yinda

    2010-01-01

    The aim of this work is to investigate Ant Colony Algorithm for the traveling salesman problem (TSP). Ants of the artificial colony are able to generate successively shorter feasible tours by using information accumulated in the form of a pheromone trail deposited on the edges of the TSP graph. This paper is based on the ideas of ant colony algorithm and analysis the main parameters of the ant colony algorithm. Experimental results for solving TSP problems with ant colony algorithm show great...

  17. The effects of aluminum and nickel in nectar on the foraging behavior of bumblebees

    International Nuclear Information System (INIS)

    Metals in soil are known to negatively affect the health of many groups of organisms, but it is unclear whether they can affect plant-pollinator interactions, and whether pollinators that visit plants growing on contaminated soils are at risk of ingesting potentially toxic resources. We address whether the presence of metals in nectar alters foraging behavior by bumblebees by manipulating nectar with one of two common soil contaminants (Al or Ni) in flowers of Impatiens capensis (Balsaminaceae). While the presence of Al in nectar did not influence foraging patterns by bumblebees, flowers containing Ni nectar solutions were visited for shorter time periods relative to controls, and discouraged bees from visiting nearby Ni-contaminated flowers. However, because bumblebees still visited these flowers, they likely ingested a potentially toxic resource. Our findings suggest that soil metals could cascade to negatively affect pollinators in metal contaminated environments. -- Highlights: ► We address whether metals in nectar alter foraging behavior by bumblebees. ► Al in nectar did not influence foraging patterns by bumblebees. ► Ni nectar solutions were visited for shorter time periods relative to controls. ► Ni nectar solutions discouraged bees from visiting nearby Ni-contaminated flowers. ► Our findings suggest soil metals could cascade to negatively affect pollinators. -- We extend current understanding of the effects of plant chemistry on plant-pollinator interactions by describing the effects of metals in nectar on bee foraging

  18. Space use of bumblebees (Bombus spp. revealed by radio-tracking.

    Directory of Open Access Journals (Sweden)

    Melanie Hagen

    Full Text Available BACKGROUND: Accurate estimates of movement behavior and distances travelled by animals are difficult to obtain, especially for small-bodied insects where transmitter weights have prevented the use of radio-tracking. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first successful use of micro radio telemetry to track flight distances and space use of bumblebees. Using ground surveys and Cessna overflights in a Central European rural landscape mosaic we obtained maximum flight distances of 2.5 km, 1.9 km and 1.3 km for Bombus terrestris (workers, Bombus ruderatus (worker, and Bombus hortorum (young queens, respectively. Bumblebee individuals used large areas (0.25-43.53 ha within one or a few days. Habitat analyses of one B. hortorum queen at the landscape scale indicated that gardens within villages were used more often than expected from habitat availability. Detailed movement trajectories of this individual revealed that prominent landscape structures (e.g. trees and flower patches were repeatedly visited. However, we also observed long (i.e. >45 min resting periods between flights (B. hortorum and differences in flower-handling between bumblebees with and without transmitters (B. terrestris suggesting that the current weight of transmitters (200 mg may still impose significant energetic costs on the insects. CONCLUSIONS/SIGNIFICANCE: Spatio-temporal movements of bumblebees can now be tracked with telemetry methods. Our measured flight distances exceed many previous estimates of bumblebee foraging ranges and suggest that travelling long distances to food resources may be common. However, even the smallest currently available transmitters still appear to compromise flower handling performance and cause an increase in resting behavior of bees. Future reductions of transmitter mass and size could open up new avenues for quantifying landscape-scale space use of insect pollinators and could provide novel insights into the behavior and

  19. Photoreceptor spectral sensitivity in the bumblebee, Bombus impatiens (Hymenoptera: Apidae.

    Directory of Open Access Journals (Sweden)

    Peter Skorupski

    Full Text Available The bumblebee Bombus impatiens is increasingly used as a model in comparative studies of colour vision, or in behavioural studies relying on perceptual discrimination of colour. However, full spectral sensitivity data on the photoreceptor inputs underlying colour vision are not available for B. impatiens. Since most known bee species are trichromatic, with photoreceptor spectral sensitivity peaks in the UV, blue and green regions of the spectrum, data from a related species, where spectral sensitivity measurements have been made, are often applied to B impatiens. Nevertheless, species differences in spectral tuning of equivalent photoreceptor classes may result in peaks that differ by several nm, which may have small but significant effects on colour discrimination ability. We therefore used intracellular recording to measure photoreceptor spectral sensitivity in B. impatiens. Spectral peaks were estimated at 347, 424 and 539 nm for UV, blue and green receptors, respectively, suggesting that this species is a UV-blue-green trichromat. Photoreceptor spectral sensitivity peaks are similar to previous measurements from Bombus terrestris, although there is a significant difference in the peak sensitivity of the blue receptor, which is shifted in the short wave direction by 12-13 nm in B. impatiens compared to B. terrestris.

  20. Bumblebee visual search for multiple learned target types.

    Science.gov (United States)

    Nityananda, Vivek; Pattrick, Jonathan G

    2013-11-15

    Visual search is well studied in human psychology, but we know comparatively little about similar capacities in non-human animals. It is sometimes assumed that animal visual search is restricted to a single target at a time. In bees, for example, this limitation has been evoked to explain flower constancy, the tendency of bees to specialise on a single flower type. Few studies, however, have investigated bee visual search for multiple target types after extended learning and controlling for prior visual experience. We trained colour-naive bumblebees (Bombus terrestris) extensively in separate discrimination tasks to recognise two rewarding colours in interspersed block training sessions. We then tested them with the two colours simultaneously in the presence of distracting colours to examine whether and how quickly they were able to switch between the target colours. We found that bees switched between visual targets quickly and often. The median time taken to switch between targets was shorter than known estimates of how long traces last in bees' working memory, suggesting that their capacity to recall more than one learned target was not restricted by working memory limitations. Following our results, we propose a model of memory and learning that integrates our findings with those of previous studies investigating flower constancy. PMID:23948481

  1. Great Big Hairy Bees! Regulating the European Bumblebee, Bombus Terrestris L. What does it say about the Precautionary Principle?

    Directory of Open Access Journals (Sweden)

    Cameron Alastair Moore

    2012-06-01

    Full Text Available The previous Commonwealth Minister for the Environment, Mr Garrett, recently rejected a request to allow the importation of live bumblebees (Bombus terrestris L. to mainland Australia. New South Wales and Victoria had already listed the introduction of bumblebees as, respectively, a key threatening process and a potentially threatening process. The Commonwealth, however, had previously declined an application to list the introduction of bumblebees as a key threatening process, although its Threatened Species Scientific Committee urged ‘that extreme caution be shown in considering any proposal to introduce this species to the mainland.’ The potential threat from bumblebees would appear to beg the questions posed by the precautionary principle. Would the presence of bumblebees to mainland Australia pose a threat of serious or irreversible environmental damage? Should a lack of full scientific certainty be used as a reason for postponing measures to prevent environmental degradation? This paper considers the role of the precautionary principle in regulatory approaches to the bumblebee. It seeks to establish the application of the precautionary principle to this particular potential environmental threat, including its relationship to the principle of conservation of biological diversity. It concludes that, despite widespread adoption of the precautionary principle in policy, legislation and case law in Australia, its impact on regulating bumblebees has not been consistent.

  2. Leg tendon glands in male bumblebees (Bombus terrestris): structure, secretion chemistry, and possible functions

    Czech Academy of Sciences Publication Activity Database

    Jarau, S.; Žáček, Petr; Šobotník, Jan; Vrkoslav, Vladimír; Hadravová, Romana; Coppée, Audrey; Vašíčková, Soňa; Jiroš, Pavel; Valterová, Irena

    2012-01-01

    Roč. 99, č. 12 (2012), s. 1039-1049. ISSN 0028-1042 R&D Projects: GA TA ČR TA01020969 Institutional support: RVO:61388963 Keywords : bumblebee * hydrocarbons * leg tendon glands * sex specific secretion * wax esters Subject RIV: CC - Organic Chemistry Impact factor: 2.144, year: 2012

  3. The role of desaturases in the biosynthesis of marking pheromones in bumblebee males

    Czech Academy of Sciences Publication Activity Database

    Buček, Aleš; Vogel, H.; Matoušková, Petra; Prchalová, Darina; Žáček, Petr; Vrkoslav, Vladimír; Šebesta, Petr; Svatoš, Aleš; Jahn, Ullrich; Valterová, Irena; Pichová, Iva

    2013-01-01

    Roč. 43, č. 8 (2013), s. 724-731. ISSN 0965-1748 R&D Projects: GA ČR GA203/09/1446 Institutional support: RVO:61388963 Keywords : fatty acid desaturase * bumblebee * Hymenoptera * pheromone * RNA-seq * functional expression Subject RIV: CE - Biochemistry Impact factor: 3.420, year: 2013

  4. Large scale patterns of abundance and distribution of parasites in Mexican bumblebees.

    Science.gov (United States)

    Gallot-Lavallée, Marie; Schmid-Hempel, Regula; Vandame, Rémy; Vergara, Carlos H; Schmid-Hempel, Paul

    2016-01-01

    Bumblebees are highly valued for their pollination services in natural ecosystems as well as for agricultural crops. These precious pollinators are known to be declining worldwide, and one major factor contributing to this decline are infections by parasites. Knowledge about parasites in wild bumblebee populations is thus of paramount importance for conservation purposes. We here report the geographical distribution of Crithidia and Nosema, two common parasites of bumblebees, in a yet poorly investigated country: Mexico. Based on sequence divergence of the Cytochrome b and Glycosomal glyceraldehyde phosphate deshydrogenase (gGPDAH) genes, we discovered the presence of a new Crithidia species, which is mainly distributed in the southern half of the country. It is placed by Bayesian inference as a sister species to C. bombi. We suggest the name Crithidia mexicana for this newly discovered organism. A population of C. expoeki was encountered concentrated on the flanks of the dormant volcanic mountain, Iztaccihuatl, and microsatellite data showed evidence of a bottleneck in this population. This study is the first to provide a large-scale insight into the health status of endemic bumblebees in Mexico, based on a large sample size (n=3,285 bees examined) over a variety of host species and habitats. PMID:26678506

  5. Estimating species richness and status of solitary bees and bumblebees in agricultural semi-natural habitats

    DEFF Research Database (Denmark)

    Calabuig, Isabel

    2000-01-01

    agricultural landscape, 72 solitary bee species and 19 species of bumblebees were recorded, several of which are considered vulnerable or endangered in neighbouring countries. Nesting conditions for rare cavity-nesting species and the possible role of the semi-natural habitats as corridors for species...

  6. Unusual fatty acids in the fat body of the early nesting bumblebee, Bombus pratorum

    Czech Academy of Sciences Publication Activity Database

    Cvačka, Josef; Kofroňová, Edita; Vašíčková, Soňa; Stránský, Karel; Jiroš, Pavel; Hovorka, Oldřich; Kindl, Jiří; Valterová, Irena

    2008-01-01

    Roč. 43, č. 5 (2008), s. 441-450. ISSN 0024-4201 R&D Projects: GA AV ČR IAA4055403; GA MŠk 2B06007 Institutional research plan: CEZ:AV0Z40550506 Keywords : bumblebees * fat body lipids * marking pheromone biosynthesis Subject RIV: CC - Organic Chemistry Impact factor: 1.888, year: 2008

  7. How Bumblebees First Find Flowers: Habituation of Visual Pattern Preferences, Spontaneous Recovery, and Dishabituation

    Science.gov (United States)

    Plowright, C. M. S.; Simonds, V. M.; Butler, M. A.

    2006-01-01

    Two experiments examined the exploratory behaviour of flower-naive bumblebees. Bees were tested four times in a 12-arm radial arm maze in which they never received reward. Patterned and unpatterned stimuli were presented at the end of each corridor and the choices of the bees were recorded. We examined the effects of two variables, time and the…

  8. The alien's identity: consequences of taxonomic status for the international bumblebee trade regulations

    Czech Academy of Sciences Publication Activity Database

    Lecocq, T.; Coppée, A.; Michez, D.; Brasero, N.; Rasplus, J. Y.; Valterová, Irena; Rasmont, P.

    2016-01-01

    Roč. 195, Mar (2016), s. 169-176. ISSN 0006-3207 R&D Projects: GA ČR(CZ) GA14-04291S Institutional support: RVO:61388963 Keywords : alien taxa * evolutionary significant units * integrative taxonomy * species international trade * bumblebee Subject RIV: EG - Zoology Impact factor: 3.762, year: 2014

  9. An integrative taxonomic approach to assess the status of Corsican bumblebees: implications for conservation

    Czech Academy of Sciences Publication Activity Database

    Lecocq, T.; Brasero, N.; De Meulemeester, T.; Michez, D.; Dellicour, S.; Lhomme, P.; de Jonghe, R.; Valterová, Irena; Urbanová, Klára; Rasmont, P.

    2015-01-01

    Roč. 18, č. 3 (2015), s. 236-248. ISSN 1367-9430 Institutional support: RVO:61388963 Keywords : Bayesian * bumblebees * endemic * evolutionarily significant unit * genetic marker * insular Subject RIV: CC - Organic Chemistry Impact factor: 2.852, year: 2014

  10. The logic of hypersocial colonies

    DEFF Research Database (Denmark)

    Pedersen, Jes Søe

    2012-01-01

    It is no wonder that we are transfixed with fascination when we stand in the midst of an ocean of flowing ants within a single extensive society of one of the invasive species. Normal terms do not fit anymore: this is not just a colony, but a “supercolony.” The iconic supercolonial species is the...... Argentine ant, infamous as a pest and now very well studied, all the way from having its genome sequenced to its global distribution mapped. As the Argentine ant can be the key to understanding other supercolonial and/or invasive ants, it is very timely that Moffett's review (2012) focuses on how we...

  11. First Chemical Analysis and Characterization of the Male Species-Specific Cephalic Labial-Gland Secretions of South American Bumblebees.

    Science.gov (United States)

    Brasero, Nicolas; Martinet, Baptiste; Urbanová, Klára; Valterová, Irena; Torres, Alexandra; Hoffmann, Wolfgang; Rasmont, Pierre; Lecocq, Thomas

    2015-10-01

    The evolution of signals and reproductive traits involved in the pre-mating recognition has been in focus of abundant research in several model species, such as bumblebees (genus Bombus). However, the most-studied bumblebee reproductive trait, the male cephalic labial gland secretions (CLGS), remains unknown among bumblebee species from South America. In this study, the CLGS of five South American bumblebees of the subgenera Thoracobombus (Bombus excellens and B. atratus) and Cullumanobombus (B. rubicundus, B. hortulanus, and B. melaleucus) were investigated, by comparing the chemical compositions of their secretions to those of closely related European species. The results showed an obvious interspecific differentiation in both subgenera. The interspecific differentiation among the species of the Thoracobombus subgenus involved different compounds present at high contents (main compounds), while those of the Cullumanobombus subgenus shared the same main components. This suggests that among the species of the Cullumanobombus subgenus, the differentiation in minor components could lead to species discrimination. PMID:26460558

  12. Asymmetrical disassortative pollination in a distylous primrose: the complementary roles of bumblebee nectar robbers and syrphid flies

    OpenAIRE

    Zhu, Xing-Fu; Jiang, Xian-feng; Li, Li; Zhang, Zhi-Qiang; Li, Qing-Jun

    2015-01-01

    Heterostyly is a floral polymorphism characterized by reciprocal herkogamy maintained through high levels of mating between morphs, serviced by appropriate pollinators. We studied how differential efficiency and abundance of distinct pollinators affect plant female reproduction in self- and intra-morph incompatible distylous Primula secundiflora. Bumblebees and syrphid flies were found to be the most abundant floral visitors. Bumblebees frequently exhibited nectar-robbing behavior. Because th...

  13. Ant Colony Optimization

    OpenAIRE

    Zahálka, Jaroslav

    2007-01-01

    This diploma thesis deals with Ant Colony algorithms and their usage for solving Travelling Salesman Problems and Vehicle Routing Problems. These algorithms are metaheuristics offering new approach to solving NP-hard problems. Work begins with a description of the forementioned tasks including ways to tackle them. Next chapter analyses Ant Colony metaheuristic and its possible usage and variations. The most important part of the thesis is practical and is represented by application Ant Colony...

  14. Fitness club

    CERN Multimedia

    Fitness club

    2011-01-01

    General fitness Classes Enrolments are open for general fitness classes at CERN taking place on Monday, Wednesday, and Friday lunchtimes in the Pump Hall (building 216). There are shower facilities for both men and women. It is possible to pay for 1, 2 or 3 classes per week for a minimum of 1 month and up to 6 months. Check out our rates and enrol at: http://cern.ch/club-fitness Hope to see you among us! CERN Fitness Club fitness.club@cern.ch  

  15. Flight activity of 4-lb Australian package bee colonies used for almond pollination.

    Science.gov (United States)

    Increasing acreage of almonds in California has increased the demand for honey bee colonies for pollination. Since 2005, domestic U.S. colonies have been supplemented with colonies started from package bees imported from Australia. The need for almond pollination in late winter in California fits we...

  16. Specters of Colonialism

    DEFF Research Database (Denmark)

    Muhr, Sara Louise; Azad, Salam

    2013-01-01

    This paper investigates how an organization in Sweden, a country normally not considered among the former colonial powers, is still haunted by the specters of a western colonial history. Based on in-depth interviews as well as participant observation in the headquarters of a Swedish multinational...

  17. Enhanced Bee Colony Algorithm for Complex Optimization Problems

    Directory of Open Access Journals (Sweden)

    S.Suriya

    2012-01-01

    Full Text Available Optimization problems are considered to be one kind of NP hard problems. Usually heuristic approaches are found to provide solutions for NP hard problems. There are a plenty of heuristic algorithmsavailable to solve optimization problems namely: Ant Colony Optimization, Particle Swarm Optimization, Bee Colony Optimization, etc. The basic Bee Colony algorithm, a population based search algorithm, is analyzed to be a novel tool for complex optimization problems. The algorithm mimics the food foraging behavior of swarmsof honey bees. This paper deals with a modified fitness function of Bee Colony algorithm. The effect of problem dimensionality on the performance of the algorithms will be investigated. This enhanced Bee Colony Optimization will be evaluated based on the well-known benchmark problems. The testing functions like Rastrigin, Rosenbrock, Ackley, Griewank and Sphere are used to evaluavate the performance of the enhanced Bee Colony algorithm. The simulation will be developed on MATLAB.

  18. An immune response in the bumblebee, Bombus terrestris leads to increased food consumption

    Directory of Open Access Journals (Sweden)

    Mallon Eamonn B

    2006-07-01

    Full Text Available Abstract Background The concept of a costly immune system that must be traded off against other important physiological systems is fundamental to the burgeoning field of ecological immunity. Bumblebees have become one of the central models in this field. Although previous work has demonstrated costs of immunity in numerous life history traits, estimates of the more direct costs of bumblebee immunity have yet to be made. Results Here we show a 7.5% increase in energy consumption in response to non-pathogenic immune stimulation. Conclusion This increase in energy consumption along with other results suggests that immunity is one of the most important physiological systems, with other systems being sacrificed for its continuing efficiency. This increased consumption and maintained activity contrasts with the sickness-induced anorexia and reduced activity found in vertebrates.

  19. Fatty Acids from Pool Lipids as Possible Precursors of the Male Marking Pheromone in Bumblebees

    Directory of Open Access Journals (Sweden)

    Edita Kofroňová

    2014-02-01

    Full Text Available Triacylglycerols (TGs stored in the fat bodies of bumblebee males have a species-specific composition. The striking structural similarities between TG fatty acids (FAs and components of the male marking pheromone in certain species led to the hypothesis that FAs may serve as precursors in pheromone biosynthesis. Here, we analysed TGs from B. ruderatus, B. bohemicus, and B. campestris. Nonadec-9-ene and icos-15-en-1-ol are the main components of B. ruderatus labial gland secretion, forming up to 92% of the gland extract. The corresponding icos-11-enic and icos-15-enic acids were found in TGs at levels higher than usual for bumblebee species. We found similar relationships in B. campestris and B. bohemicus. These results suggest that FAs might be precursors of aliphatic compounds in the male pheromones. Furthermore, we report for the first time the pheromone structure of B. ruderatus males.

  20. Surpassing Mt. Everest: extreme flight performance of alpine bumble-bees.

    Science.gov (United States)

    Dillon, Michael E; Dudley, Robert

    2014-02-01

    Animal flight at altitude involves substantial aerodynamic and physiological challenges. Hovering at high elevations is particularly demanding from the dual perspectives of lift and power output; nevertheless, some volant insects reside and fly at elevations in excess of 4000 m. Here, we demonstrate that alpine bumble-bees possess substantial aerodynamic reserves, and can sustain hovering flight under hypobaria at effective elevations in excess of 9000 m, i.e. higher than Mt. Everest. Modulation of stroke amplitude and not wingbeat frequency is the primary means of compensation for overcoming the aerodynamic challenge. The presence of such excess capacity in a high-altitude bumble-bee is surprising and suggests intermittent behavioural demands for extreme flight performance supplemental to routine foraging. PMID:24501268

  1. Bumblebees minimize control challenges by combining active and passive modes in unsteady winds

    CERN Document Server

    Ravi, Sridhar; Engels, Thomas; Schneider, Kai; Wang, Chun; Sesterhenn, Joern; Liu, Hao

    2016-01-01

    The natural wind environment that volant insects encounter is unsteady and highly complex, posing significant flight control and stability challenges. Unsteady airflows can range from structured chains of discrete vortices shed in the wake of an object to fully developed chaotic turbulence. It is critical to understand the flight control strategies insect employ to safely navigate in natural environments. We combined experiments on free flying bumblebees with high fidelity numerical simulations and lower order modeling to identify the salient mechanics that mediate insect flight in unsteady winds. We trained bumblebees to fly upwind towards an artificial flower in a wind tunnel under steady wind and in a von Karman street (23Hz) formed in the wake of a cylinder. The bees displayed significantly higher movement in the unsteady vortex street compared to steady winds. Correlation analysis revealed that at lower frequencies, less than 10 Hz, in both steady and unsteady winds the bees mediated lateral movement wit...

  2. Fitness cost

    DEFF Research Database (Denmark)

    Nielsen, Karen L.; Pedersen, Thomas M.; Udekwu, Klas I.;

    2012-01-01

    phage types, predominantly only penicillin resistant. We investigated whether isolates of this epidemic were associated with a fitness cost, and we employed a mathematical model to ask whether these fitness costs could have led to the observed reduction in frequency. Bacteraemia isolates of S. aureus...... of each isolate was determined in a growth competition assay with a reference isolate. Significant fitness costs of 215 were determined for the MRSA isolates studied. There was a significant negative correlation between number of antibiotic resistances and relative fitness. Multiple regression analysis...... found significantly independent negative correlations between fitness and the presence of mecA or streptomycin resistance. Mathematical modelling confirmed that fitness costs of the magnitude carried by these isolates could result in the disappearance of MRSA prevalence during a time span similar...

  3. Space use of bumblebees (Bombus spp.) revealed by radio-tracking

    OpenAIRE

    Hagen, Melanie; Wikelski, Martin; Kissling, W. Daniel

    2011-01-01

    Background: Accurate estimates of movement behavior and distances travelled by animals are difficult to obtain, especially for small-bodied insects where transmitter weights have prevented the use of radio-tracking.Methodology/Principal Findings: Here, we report the first successful use of micro radio telemetry to track flight distances and space use of bumblebees. Using ground surveys and Cessna overflights in a Central European rural landscape mosaic we obtained maximum flight distances of ...

  4. Trade-off between travel distance and prioritization of high-reward sites in traplining bumblebees

    OpenAIRE

    Lihoreau, Mathieu; Chittka, Lars; Raine, Nigel

    2011-01-01

    1. Animals exploiting renewable resource patches are faced with complex multi-location routing problems. In many species, individuals visit foraging patches in predictable sequences called traplines. However, whether and how they optimize their routes remains poorly understood. 2. In this study, we demonstrate that traplining bumblebees (Bombus terrestris) make a trade-off between minimizing travel distance and prioritizing the most rewarding feeding locations. 3. Individual bees trained to...

  5. Primary sensory processing of visual and olfactory signals in the bumblebee brain

    OpenAIRE

    Mertes, Marcel

    2013-01-01

    Since decades honeybees are being used as an insect model system for answering scientific questions in a variety of areas. This is due to their enormous behavioural repertoire paired with their learning capabilities. Similar learning capabilities are also evident in bumblebees that are closely related to honeybees. As honeybees, they are central place foragers that commute between a reliable food source and their nest and, therefore, need to remember particular facets of their environment ...

  6. Rainwater in cupulate bracts repels seed herbivores in a bumblebee-pollinated subalpine flower

    OpenAIRE

    Sun, Shi-Guo; Huang, Shuang-Quan

    2015-01-01

    Floral herbivory may have deleterious effects on the reproductive success of flowering plants. However, plants may evolve floral traits that allow them to defend against herbivory in particular conditions. A bumblebee-pollinated subalpine herb, Pedicularis rex (Orobanchaceae), endemic to southwest China, has cup-like bracts that fill with rainwater, which submerges its corolla tubes. We hypothesized that these water-filled cupulate bracts function to deter nectar robbers and/or seed herbivore...

  7. Foraging scent marks of bumblebees: footprint cues rather than pheromone signals

    Science.gov (United States)

    Wilms, Jessica; Eltz, Thomas

    2008-02-01

    In their natural habitat foraging bumblebees refuse to land on and probe flowers that have been recently visited (and depleted) by themselves, conspecifics or other bees, which increases their overall rate of nectar intake. This avoidance is often based on recognition of scent marks deposited by previous visitors. While the term ‘scent mark’ implies active labelling, it is an open question whether the repellent chemicals are pheromones actively and specifically released during flower visits, or mere footprints deposited unspecifically wherever bees walk. To distinguish between the two possibilities, we presented worker bumblebees ( Bombus terrestris) with three types of feeders in a laboratory experiment: unvisited control feeders, passive feeders with a corolla that the bee had walked over on its way from the nest (with unspecific footprints), and active feeders, which the bee had just visited and depleted, but which were immediately refilled with sugar water (potentially with specific scent marks). Bumblebees rejected both active and passive feeders more frequently than unvisited controls. The rate of rejection of passive feeders was only slightly lower than that of active feeders, and this difference vanished completely when passive corollas were walked over repeatedly on the way from the nest. Thus, mere footprints were sufficient to emulate the repellent effect of an actual feeder visit. In confirmation, glass slides on which bumblebees had walked on near the nest entrance accumulated hydrocarbons (alkanes and alkenes, C23 to C31), which had previously been shown to elicit repellency in flower choice experiments. We conclude that repellent scent marks are mere footprints, which foraging bees avoid when they encounter them in a foraging context.

  8. Comparison of flower constancy and foraging performance in three bumblebee species (Hymenoptera: Apidae: Bombus)

    OpenAIRE

    Raine, N.E.; Chittka, L.

    2005-01-01

    The three bumblebee species Bombus terrestris (Linnaeus 1758), Bombus lapidarius (Linnaeus 1758), and Bombus pascuorum (Scopoli 1763) showed consistent differences in their respective levels of flower constancy when foraging on three different pairs of flower species. B. terrestris was always the most flower constant, followed by B. lapidarius, with B. pascuorum the least flower constant species. These interspecific differences in flower constancy were related to foraging performance under fi...

  9. Surpassing Mt. Everest: extreme flight performance of alpine bumble-bees

    OpenAIRE

    Dillon, Michael E.; Dudley, Robert

    2014-01-01

    Animal flight at altitude involves substantial aerodynamic and physiological challenges. Hovering at high elevations is particularly demanding from the dual perspectives of lift and power output; nevertheless, some volant insects reside and fly at elevations in excess of 4000 m. Here, we demonstrate that alpine bumble-bees possess substantial aerodynamic reserves, and can sustain hovering flight under hypobaria at effective elevations in excess of 9000 m, i.e. higher than Mt. Everest. Modulat...

  10. Geographic profiling applied to testing models of bumble-bee foraging

    OpenAIRE

    Raine, N. E.; Rossmo, D. K.; Le Comber, S. C.

    2008-01-01

    Geographical profiling (GP) was originally developed as a statistical tool to help police forces prioritize lists of suspects in investigations of serial crimes. GP uses the location of related crime sites to make inferences about where the offender is most likely to live, and has been extremely successful in criminology. Here, we show how GP is applicable to experimental studies of animal foraging, using the bumble-bee Bombus terrestris. GP techniques enable us to simplify complex patterns o...

  11. The psychophysics of sugar concentration discrimination and contrast evaluation in bumblebees

    OpenAIRE

    Nachev, Vladislav; James D Thomson; Winter, York

    2012-01-01

    The capacity to discriminate between choice options is crucial for a decision-maker to avoid unprofitable options. The physical properties of rewards are presumed to be represented on context-dependent, nonlinear cognitive scales that may systematically influence reward expectation and thus choice behavior. In this study, we investigated the discrimination performance of free-flying bumblebee workers (Bombus impatiens) in a choice between sucrose solutions with different concentrations. We co...

  12. Fitness Club

    CERN Multimedia

    Fitness Club

    2011-01-01

    The CERN Fitness Club is organising Zumba Classes on the first Wednesday of each month, starting 7 September (19.00 – 20.00). What is Zumba®? It’s an exhilarating, effective, easy-to-follow, Latin-inspired, calorie-burning dance fitness-party™ that’s moving millions of people toward joy and health. Above all it’s great fun and an excellent work out. Price: 22 CHF/person Sign-up via the following form: https://espace.cern.ch/club-fitness/Lists/Zumba%20Subscription/NewForm.aspx For more info: fitness.club@cern.ch

  13. Molecular cloning and characterization of a venom phospholipase A2 from the bumblebee Bombus ignitus.

    Science.gov (United States)

    Xin, Yu; Choo, Young Moo; Hu, Zhigang; Lee, Kwang Sik; Yoon, Hyung Joo; Cui, Zheng; Sohn, Hung Dae; Jin, Byung Rae

    2009-10-01

    Phospholipase A(2) (PLA(2)) is one of the main components of bee venom. Here, we identify a venom PLA(2) from the bumblebee, Bombus ignitus. Bumblebee venom PLA(2) (Bi-PLA(2)) cDNA, which was identified by searching B. ignitus venom gland expressed sequence tags, encodes a 180 amino acid protein. Comparison of the genomic sequence with the cDNA sequence revealed the presence of four exons and three introns in the Bi-PLA(2) gene. Bi-PLA(2) is an 18-kDa glycoprotein. It is expressed in the venom gland, cleaved between the residues Arg44 and Ile45, and then stored in the venom sac. Comparative analysis revealed that the mature Bi-PLA(2) (136 amino acids) possesses features consistent with other bee PLA(2)s, including ten conserved cysteine residues, as well as a highly conserved Ca(2+)-binding site and active site. Phylogenetic analysis of bee PLA(2)s separated the bumblebee and honeybee PLA(2) proteins into two groups. The mature Bi-PLA(2) purified from the venom of B. ignitus worker bees hydrolyzed DBPC, a known substrate of PLA(2). Immunofluorescence staining of Bi-PLA(2)-treated insect Sf9 cells revealed that Bi-PLA(2) binds at the cell membrane and induces apoptotic cell death. PMID:19539776

  14. Wing wear reduces bumblebee flight performance in a dynamic obstacle course.

    Science.gov (United States)

    Mountcastle, Andrew M; Alexander, Teressa M; Switzer, Callin M; Combes, Stacey A

    2016-06-01

    Previous work has shown that wing wear increases mortality in bumblebees. Although a proximate mechanism for this phenomenon has remained elusive, a leading hypothesis is that wing wear increases predation risk by reducing flight manoeuvrability. We tested the effects of simulated wing wear on flight manoeuvrability in Bombus impatiens bumblebees using a dynamic obstacle course designed to push bees towards their performance limits. We found that removing 22% wing area from the tips of both forewings (symmetric wear) caused a 9% reduction in peak acceleration during manoeuvring flight, while performing the same manipulation on only one wing (asymmetric wear) did not significantly reduce maximum acceleration. The rate at which bees collided with obstacles was correlated with body length across all treatments, but wing wear did not increase collision rate, possibly because shorter wingspans allow more room for bees to manoeuvre. This study presents a novel method for exploring extreme flight manoeuvres in flying insects, eliciting peak accelerations that exceed those measured during flight through a stationary obstacle course. If escape from aerial predation is constrained by acceleration capacity, then our results offer a potential explanation for the observed increase in bumblebee mortality with wing wear. PMID:27303054

  15. Exploring complex pheromone biosynthetic processes in the bumblebee male labial gland by RNA sequencing.

    Science.gov (United States)

    Buček, A; Brabcová, J; Vogel, H; Prchalová, D; Kindl, J; Valterová, I; Pichová, I

    2016-06-01

    Male marking pheromones (MPs) are used by the majority of bumblebee species (Hymenoptera: Apidae), including a commercially important greenhouse pollinator, the buff-tailed bumblebee (Bombus terrestris), to attract conspecific females. MP biosynthetic processes in the cephalic part of the bumblebee male labial gland (LG) are of extraordinary complexity, involving enzymes of fatty acid and isoprenoid biosynthesis, which jointly produce more than 50 compounds. We employed a differential transcriptomic approach to identify candidate genes involved in MP biosynthesis by sequencing Bombus terrestris LG and fat body (FB) transcriptomes. We identified 12 454 abundantly expressed gene products (reads per kilobase of exon model per million mapped reads value > 1) that had significant hits in the GenBank nonredundant database. Of these, 876 were upregulated in the LG (> 4-fold difference). We identified more than 140 candidate genes potentially involved in MP biosynthesis, including esterases, fatty acid reductases, lipases, enzymes involved in limited fatty acid chain shortening, neuropeptide receptors and enzymes involved in biosynthesis of triacylglycerols, isoprenoids and fatty acids. For selected candidates, we confirmed their abundant expression in LG using quantitative real-time reverse transcription-PCR (qRT-PCR). Our study shows that the Bombus terrestris LG transcriptome reflects both fatty acid and isoprenoid MP biosynthetic processes and identifies rational gene targets for future studies to disentangle the molecular basis of MP biosynthesis. Additionally, LG and FB transcriptomes enrich the available transcriptomic resources for Bombus terrestris. PMID:26945888

  16. Fodbold Fitness

    DEFF Research Database (Denmark)

    Bennike, Søren

    Samfundet forandrer sig og ligeså gør danskernes idrætsmønstre. Fodbold Fitness, der er afhandlingens omdrejningspunkt, kan iagttages som en reaktion på disse forandringer. Afhandlingen ser nærmere på Fodbold Fitness og implementeringen af dette, der ingenlunde er nogen let opgave. Bennike bidrager...

  17. Asymmetrical disassortative pollination in a distylous primrose: the complementary roles of bumblebee nectar robbers and syrphid flies.

    Science.gov (United States)

    Zhu, Xing-Fu; Jiang, Xian-Feng; Li, Li; Zhang, Zhi-Qiang; Li, Qing-Jun

    2015-01-01

    Heterostyly is a floral polymorphism characterized by reciprocal herkogamy maintained through high levels of mating between morphs, serviced by appropriate pollinators. We studied how differential efficiency and abundance of distinct pollinators affect plant female reproduction in self- and intra-morph incompatible distylous Primula secundiflora. Bumblebees and syrphid flies were found to be the most abundant floral visitors. Bumblebees frequently exhibited nectar-robbing behavior. Because the robbing holes were always situated between the high- and low-level organs on both morphs, nectar-robbing bumblebees only pollinated S-styled flowers. L-styled flowers set four times as many seeds as did S-styled flowers after being visited by pollen-collecting syrphid flies. The natural female fecundity and the magnitude of pollen limitation varied between the morphs within populations because of the mosaic distribution of nectar-robbing bumblebees and syrphid flies. L-styled flowers and S-styled flowers set the same number of seeds after supplemental hand pollination, indicating equivalent female reproductive potential. We suggest that bumblebee nectar robbers and syrphid flies play an important role in sustaining the floral dimorphism of heterostyly in P. secundiflora because of their complementary roles in the pollination system. PMID:25579323

  18. Tropilaelaps of bees - epizootiological picture with special emphasis on the first description of the parasite in bumblebees and bees in Serbia

    Directory of Open Access Journals (Sweden)

    Manić Marija

    2014-01-01

    Full Text Available Honey bees are the most significant pollinators of plants worlwide. Importance of plant pollination widely exceeds all other economic benefits of modern beekeeping such as production of honey, Royal jelly, propolis, beeswax, honeybee venom etc. The issues concerning bees diseases are of extreme importance in modern commercial beekeeping. That especially regards to the fact that the number of disease agents in bees has considerably increased in recent decades. Using international transport, export or import of bees and their products, the possibility of entering various agents (parasites, bacterias, viruses and fungi into bee colonies. In recent years one of the biggest problems in beekeeping in Asia has become tropilaelaps - ectoparasitic bee disease caused by mites of the genus Tropilaelaps. But because of prevalent interest in parasites Varroa destructor and Acarapis woodi, the threat of mites from Tropileaps family has not been familiar for a long period of time. Today, Tropilaelaps is on the list of diseases endangering the whole world, made by OIE. There is a real risk of its spreading, mostly through trade, that is import of bees, swarms, queen bees, bee products and equipment. In the Republic of Serbia, this disease was described for the first time in April-May 1981 in bumblebees and bees in which a mass infestation with until then unknown parasites was detected. By additional analysis there was found out that the parasite in question was from Laelapidae (Mesostigmata family, Tropilaelaps.

  19. Colony screening by PCR

    OpenAIRE

    sprotocols

    2014-01-01

    Author: Matt Lewis ### Notes This is the fastest way to screen bacterial colonies. Our PCR machine takes 24 tubes so I routinely screen 22 colonies + 1 negative + 1 positive control. ### Choosing the primers Ideally you want a primer pair that can only work if the correct construct is present eg. a vector flanking primer and a gene specific primer. However, this may not allow you a positive control (essential) so you might have to use both vector flanking primers instead. If y...

  20. The colonial present

    OpenAIRE

    Bunnell, Tim

    2006-01-01

    cultural geographies 2006 13: 305-312 reviews in brief The colonial present. By Derek Gregory. Malden, MA: Blackwell. 2004. 367 pp. £16.99 paper. ISBN 1577180909. The colonial present extends and deepens our understanding of contemporary geopolitics in ways that speak to the key concerns of this journal. For Derek Gregory as for Edward Said, to whom the book is dedicated, and whose intellectual legacy runs through its pages - issues of cu...

  1. ACO - Ant Colony Optimization

    OpenAIRE

    Žumer, Viljem; Brest, Janez; Pešl, Ivan

    2015-01-01

    Ant colony optimization is a relatively new approach to solving NP-Hard problems. It is based on the behavior of real ants, which always find the shortest path between their nest and a food source. Such behavior can be transferred into the discrcte world, were real ants are replaced by simple agents. Such simple agents are placed into the environment where different combinatorial problems can be solved In this paper we describe an artificial ant colony capable of solving the travelling salesm...

  2. Effects of field characteristics on abundance of bumblebees (Bombus spp.) and seed yield in red clover fields

    DEFF Research Database (Denmark)

    Wermuth, Kirsten Haugaard; Dupont, Yoko L.

    2010-01-01

    Red clover is a key floral ressource for bumblebees (Bombus spp.).We here investigate variation within and among red clover fields in species richness and abundance of Bombus spp. in addition to Apis mellifera. Bumblebee individuals were grouped into the following functional groups, based on castes...... and tongue length: (1) all queens, (2) all workers, (3) short-tongued workers and (4) long-tongued workers. In 14 study fields, no spatial or diurnal within-field differences were found in abundances of bee groups. However, seasonal differences were detected. On average 6.3±0.6 Bombus spp. were observed...... in each field. In general, maximum observed bee abundances of a field were not associated with field size, weediness, or presence of commercial honeybee hives. However, long-tongued bumblebee abundance was significantly lower in fields with beehives. Seed yield was marginally higher in less weedy fields...

  3. Fitness Club

    CERN Multimedia

    Fitness Club

    2012-01-01

    Open to All: http://cern.ch/club-fitness  fitness.club@cern.ch Boxing Your supervisor makes your life too tough ! You really need to release the pressure you've been building up ! Come and join the fit-boxers. We train three times a week in Bd 216, classes for beginners and advanced available. Visit our website cern.ch/Boxing General Fitness Escape from your desk with our general fitness classes, to strengthen your heart, muscles and bones, improve you stamina, balance and flexibility, achieve new goals, be more productive and experience a sense of well-being, every Monday, Wednesday and Friday lunchtime, Tuesday mornings before work and Thursday evenings after work – join us for one of our monthly fitness workshops. Nordic Walking Enjoy the great outdoors; Nordic Walking is a great way to get your whole body moving and to significantly improve the condition of your muscles, heart and lungs. It will boost your energy levels no end. Pilates A body-conditioning technique de...

  4. Fitness, inclusive fitness, and optimization

    OpenAIRE

    Lehmann L.; Rousset F

    2014-01-01

    Individual-as-maximizing agent analogies result in a simple understanding of the functioning of the biological world. Identifying the conditions under which individuals can be regarded as fitness maximizing agents is thus of considerable interest to biologists. Here, we compare different concepts of fitness maximization, and discuss within a single framework the relationship between Hamilton's (J Theor Biol 7: 1-16, 1964) model of social interactions, Grafen's (J Evol Biol 20: 1243-1254, 2007...

  5. Nectar vs. pollen loading affects the tradeoff between flight stability and maneuverability in bumblebees.

    Science.gov (United States)

    Mountcastle, Andrew M; Ravi, Sridhar; Combes, Stacey A

    2015-08-18

    Bumblebee foragers spend a significant portion of their lives transporting nectar and pollen, often carrying loads equivalent to more than half their body mass. Whereas nectar is stored in the abdomen near the bee's center of mass, pollen is carried on the hind legs, farther from the center of mass. We examine how load position changes the rotational moment of inertia in bumblebees and whether this affects their flight maneuverability and/or stability. We applied simulated pollen or nectar loads of equal mass to Bombus impatiens bumblebees and examined flight performance in a wind tunnel under three conditions: flight in unsteady flow, tracking an oscillating flower in smooth flow, and flower tracking in unsteady flow. Using an inertial model, we estimated that carrying a load on the legs rather than in the abdomen increases a bee's moment of inertia about the roll and yaw axes but not the pitch axis. Consistent with these predictions, we found that bees carrying a load on their legs displayed slower rotations about their roll and yaw axes, regardless of whether these rotations were driven by external perturbations or self-initiated steering maneuvers. This allowed pollen-loaded bees to maintain a more stable body orientation and higher median flight speed in unsteady flow but reduced their performance when tracking a moving flower, supporting the concept of a tradeoff between stability and maneuverability. These results demonstrate that the types of resources collected by bees affect their flight performance and energetics and suggest that wind conditions may influence resource selection. PMID:26240364

  6. Fitness Club

    CERN Multimedia

    Fitness Club

    2012-01-01

      The CERN Fitness Club is pleased to announce its new early morning class which will be taking place on: Tuesdays from 24th April 07:30 to 08:15 216 (Pump Hall, close to entrance C) – Facilities include changing rooms and showers. The Classes: The early morning classes will focus on workouts which will help you build not only strength and stamina, but will also improve your balance, and coordination. Our qualified instructor Germana will accompany you throughout the workout  to ensure you stay motivated so you achieve the best results. Sign up and discover the best way to start your working day full of energy! How to subscribe? We invite you along to a FREE trial session, if you enjoy the activity, please sign up via our website: https://espace.cern.ch/club-fitness/Activities/SUBSCRIBE.aspx. * * * * * * * * Saturday 28th April Get in shape for the summer at our fitness workshop and zumba dance party: Fitness workshop with Germana 13:00 to 14:30 - 216 (Pump Hall) Price...

  7. Fitness Basics

    Science.gov (United States)

    ... that gets your heart pumping, such as dancing, running, or swimming laps. How hard you exercise matters, too. You can learn how to measure your workout to see if it is light, medium, or intense. Fitness for all Do you have an illness or ...

  8. Fitness club

    CERN Document Server

    Fitness club

    2013-01-01

      Nordic Walking Classes Come join the Nordic walking classes and outings offered by the CERN Fitness Club starting September 2013. Our licensed instructor Christine offers classes for people who’ve never tried Nordic Walking and who would like to learn the technique, and outings for people who have completed the classes and enjoy going out as a group. Course 1: Tuesdays 12:30 - 13:30 24 September, 1 October, 8 October, 15 October Course 2: Tuesdays 12:30 - 13:30 5 November, 12 November, 19 November, 26 November Outings will take place on Thursdays (12:30 to 13:30) from 12 September 2013. We meet at the CERN Club Barracks car park (close to Entrance A) 10 minutes before departure. Prices: 50 CHF for 4 classes, including the 10 CHF Club membership. Payments made directly to instructor. Renting Poles: Poles can be rented from Christine at 5 CHF / hour. Subscription: Please subscribe at: http://cern.ch/club-fitness Looking forward to seeing you among us! Fitness Club FitnessClub@c...

  9. Fitness Club

    CERN Multimedia

    Fitness Club

    2010-01-01

    Nordic Walking Please note that the subscriptions for the general fitness classes from July to December are open: Subscriptions general fitness classes Jul-Dec 2010 Sign-up to the Fitness Club mailing list here Nordic Walking: Sign-up to the Nordic Walking mailing list here Beginners Nordic walking lessons Monday Lunchtimes (rdv 12:20 for 12:30 departure) 13.09/20.09/27.09/04.10 11.10/18.10/08.11/15.11 22.11/29.11/06.12/20.12 Nordic walking lessons Tuesday evenings (rdv 17:50 for 18:00 departure) 07.09/14.09/21.09/28.09 05.10/12.10/19.10/26.10 Intermediate/Advanced Nordic walking outings (follow the nordic walking lessons before signing up for the outings) every Thursday from 16.09 - 16.12, excluding 28.10 and 09.12 Subscriptions and info: fitness.club@cern.ch  

  10. Fitness Club

    CERN Multimedia

    Fitness Club

    2012-01-01

    Get in Shape for Summer with the CERN Fitness Club Saturday 23 June 2012 from 14:30 to 16.30 (doors open at 14.00) Germana’s Fitness Workshop. Build strength and stamina, sculpt and tone your body and get your heart pumping with Germana’s workout mixture of Cardio Attack, Power Pump, Power Step, Cardio Combat and Cross-Training. Where: 216 (Pump room – equipped with changing rooms and showers). What to wear: comfortable clothes and indoor sports shoes + bring a drink! How much: 15 chf Sign up here: https://espace.cern.ch/club-fitness/Lists/Test_Subscription/NewForm.aspx? Join the Party and dance yourself into shape at Marco + Marials Zumba Masterclass. Saturday 30 June 2012 from 15:00 to 16:30 Marco + Mariel’s Zumba Masterclass Where: 216 (Pump room – equipped with changing rooms and showers). What to wear: comfortable clothes and indoor sports shoes + bring a drink! How much: 25 chf Sign up here: https://espace.cern.ch/club-fitness/Lists/Zumba%20...

  11. Colonial American Astronomy

    Science.gov (United States)

    Yeomans, Donald K.

    2007-12-01

    While a foundation of German scientific methods enabled the rapid growth of North American Astronomy in the nineteenth century, during the seventeenth and most of the eighteenth centuries, the colonial men of science looked only to the English mother country for scientific patronage and guidance. An essay on fundamental astronomy appeared in one of the annual colonial almanacs as early as 1656, telescopic observations were made about 1660 and the first original colonial astronomical work was published by Thomas Danforth on the comet of 1664. By 1671 the Copernican ideas were so espoused at Harvard College that a physics class refused to read a Ptolemaic textbook when it was assigned to them by a senior instructor. At least in the Cambridge-Boston area, contemporary colonialist had access to the most recent scientific publications from the mother country. Observations of the great comet of 1680 by the Almanac maker, John Foster, reached Isaac Newton and were used and gratefully acknowledged in his Principia. During the seventeenth century the colonial interest in astronomy was more intense than it was for other sciences but colonists still occupied a position in the scientific backwater when compared with contemporary European scientists. Nevertheless, the science of astronomy was successfully transplanted from England to North America in the seventeenth century.

  12. Cognitive fitness.

    Science.gov (United States)

    Gilkey, Roderick; Kilts, Clint

    2007-11-01

    Recent neuroscientific research shows that the health of your brain isn't, as experts once thought, just the product of childhood experiences and genetics; it reflects your adult choices and experiences as well. Professors Gilkey and Kilts of Emory University's medical and business schools explain how you can strengthen your brain's anatomy, neural networks, and cognitive abilities, and prevent functions such as memory from deteriorating as you age. The brain's alertness is the result of what the authors call cognitive fitness -a state of optimized ability to reason, remember, learn, plan, and adapt. Certain attitudes, lifestyle choices, and exercises enhance cognitive fitness. Mental workouts are the key. Brain-imaging studies indicate that acquiring expertise in areas as diverse as playing a cello, juggling, speaking a foreign language, and driving a taxicab expands your neural systems and makes them more communicative. In other words, you can alter the physical makeup of your brain by learning new skills. The more cognitively fit you are, the better equipped you are to make decisions, solve problems, and deal with stress and change. Cognitive fitness will help you be more open to new ideas and alternative perspectives. It will give you the capacity to change your behavior and realize your goals. You can delay senescence for years and even enjoy a second career. Drawing from the rapidly expanding body of neuroscience research as well as from well-established research in psychology and other mental health fields, the authors have identified four steps you can take to become cognitively fit: understand how experience makes the brain grow, work hard at play, search for patterns, and seek novelty and innovation. Together these steps capture some of the key opportunities for maintaining an engaged, creative brain. PMID:18159786

  13. Ant Colonies Do Not Trade-Off Reproduction against Maintenance.

    Directory of Open Access Journals (Sweden)

    Boris H Kramer

    Full Text Available The question on how individuals allocate resources into maintenance and reproduction is one of the central questions in life history theory. Yet, resource allocation into maintenance on the organismic level can only be measured indirectly. This is different in a social insect colony, a "superorganism" where workers represent the soma and the queen the germ line of the colony. Here, we investigate whether trade-offs exist between maintenance and reproduction on two levels of biological organization, queens and colonies, by following single-queen colonies of the ant Cardiocondyla obscurior throughout the entire lifespan of the queen. Our results show that maintenance and reproduction are positively correlated on the colony level, and we confirm results of an earlier study that found no trade-off on the individual (queen level. We attribute this unexpected outcome to the existence of a positive feedback loop where investment into maintenance (workers increases the rate of resource acquisition under laboratory conditions. Even though food was provided ad libitum, variation in productivity among the colonies suggests that resources can only be utilized and invested into additional maintenance and reproduction by the colony if enough workers are available. The resulting relationship between per-capita and colony productivity in our study fits well with other studies conducted in the field, where decreasing per-capita productivity and the leveling off of colony productivity have been linked to density dependent effects due to competition among colonies. This suggests that the absence of trade-offs in our laboratory study might also be prevalent under natural conditions, leading to a positive association of maintenance, (= growth and reproduction. In this respect, insect colonies resemble indeterminate growing organisms.

  14. Assessment of the foraging and nesting conditions for solitary bees and bumblebees, and their distribution in a Danish agricultural landscape

    DEFF Research Database (Denmark)

    Calabuig, Isabel

    2000-01-01

    In a survey April through November 1997, a total of 72 solitary bee species and 19 bumblebee species were recorded in the semi-natural habitats of a Danish conventional agricultural landscape. The majority of the solitary non-inquiline bee species (59) were polylectic, but four oligoleges of Salix...

  15. Bombiscardovia coagulans gen. nov., sp. nov., a new member of the family Bifidobacteriaceae isolated from the digestive tract of bumblebees

    Czech Academy of Sciences Publication Activity Database

    Killer, Jiří; Kopečný, Jan; Mrázek, Jakub; Havlík, J.; Koppová, Ingrid; Benada, Oldřich; Rada, V.; Kofroňová, Olga

    2010-01-01

    Roč. 33, č. 7 (2010), s. 359-366. ISSN 0723-2020 R&D Projects: GA ČR GD525/08/H060 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50200510 Keywords : scardovia * Bifidobacteriaceae * bumblebees Subject RIV: EE - Microbiology, Virology Impact factor: 3.075, year: 2010

  16. Molecular and chemical characters to evaluate species status of two cuckoo bumblebees: Bombus barbutellus and Bombus maxillosus (Hymenoptera, Apidae, Bombini)

    Czech Academy of Sciences Publication Activity Database

    Lecocq, T.; Lhomme, P.; Michez, D.; Dellicour, S.; Valterová, Irena; Rasmont, P.

    2011-01-01

    Roč. 36, č. 3 (2011), s. 453-469. ISSN 0307-6970 Institutional research plan: CEZ:AV0Z40550506 Keywords : cuckoo bumblebees * taxonomy * molecular biology * sexual marking pheromones Subject RIV: CC - Organic Chemistry Impact factor: 2.943, year: 2011

  17. Composition and Electrophysiological Activity of Constituents Identified in Male Wing Gland Secretion of Bumblebee Parasite Aphomia sociella

    Czech Academy of Sciences Publication Activity Database

    Kalinová, Blanka; Kindl, Jiří; Jiroš, Pavel; Žáček, Petr; Vašíčková, Soňa; Buděšínský, Miloš; Valterová, Irena

    2009-01-01

    Roč. 72, č. 1 (2009), s. 8-13. ISSN 0163-3864 R&D Projects: GA MŠk 2B06007 Institutional research plan: CEZ:AV0Z40550506 Keywords : bee wax moth * electroantennography * bumblebees Subject RIV: CC - Organic Chemistry Impact factor: 3.159, year: 2009

  18. Dutch colonial anthropology in Indonesia

    OpenAIRE

    Buskens, L.P.H.M.; Kommers, J.H.M.

    2007-01-01

    Attempts to assess the results of colonial anthropology in Indonesia faced some problems, which, until recently, have not been dealt with properly. Therefore, in a newly published comprehensive history of anthropology in the Netherlands, several studies focused on the character, rather than on the substance of colonial anthropology. In the case of Dutch colonial representations of Indonesia, 'colonial anthropology' appears to be an assemblage of various disciplines that constituted a fragment...

  19. Fitness Club

    CERN Multimedia

    Fitness Club

    2012-01-01

    Nordic Walking Classes Sessions of four classes of one hour each are held on Tuesdays. RDV barracks parking at Entrance A, 10 minutes before class time. Session 1 =  11.09 / 18.09 / 25.09 / 02.10, 18:15 - 19:15 Session 2 = 25.09 / 02.10 / 09.10 / 16.10, 12:30 - 13:30 Session 3 = 23.10 / 30.10 / 06.11 / 13.11, 12:30 - 13:30 Session 4 = 20.11 / 27.11 / 04.12 / 11.12, 12:30 - 13:30 Prices 40 CHF per session + 10 CHF club membership 5 CHF/hour pole rental Check out our schedule and enroll at http://cern.ch/club-fitness   Hope to see you among us!  fitness.club@cern.ch In spring 2012 there was a long-awaited progress in CERN Fitness club. We have officially opened a Powerlifting @ CERN, and the number of members of the new section has been increasing since then reaching 70+ people in less than 4 months. Powerlifting is a strength sport, which is simple as 1-2-3 and efficient. The "1-2-3" are the three basic lifts (bench press...

  20. Colour patterns do not diagnose species: quantitative evaluation of a DNA barcoded cryptic bumblebee complex.

    Directory of Open Access Journals (Sweden)

    James C Carolan

    Full Text Available Cryptic diversity within bumblebees (Bombus has the potential to undermine crucial conservation efforts designed to reverse the observed decline in many bumblebee species worldwide. Central to such efforts is the ability to correctly recognise and diagnose species. The B. lucorum complex (Bombus lucorum, B. cryptarum and B. magnus comprises one of the most abundant and important group of wild plant and crop pollinators in northern Europe. Although the workers of these species are notoriously difficult to diagnose morphologically, it has been claimed that queens are readily diagnosable from morphological characters. Here we assess the value of colour-pattern characters in species identification of DNA-barcoded queens from the B. lucorum complex. Three distinct molecular operational taxonomic units were identified each representing one species. However, no uniquely diagnostic colour-pattern character state was found for any of these three molecular units and most colour-pattern characters showed continuous variation among the units. All characters previously deemed to be unique and diagnostic for one species were displayed by specimens molecularly identified as a different species. These results presented here raise questions on the reliability of species determinations in previous studies and highlights the benefits of implementing DNA barcoding prior to ecological, taxonomic and conservation studies of these important key pollinators.

  1. Gonadotropic and physiological functions of juvenile hormone in Bumblebee (Bombus terrestris workers.

    Directory of Open Access Journals (Sweden)

    Hagai Shpigler

    Full Text Available The evolution of advanced sociality in bees is associated with apparent modifications in juvenile hormone (JH signaling. By contrast to most insects in which JH is a gonadotropin regulating female fertility, in the highly eusocial honey bee (Apis mellifera JH has lost its gonadotrophic function in adult females, and instead regulates age-related division of labor among worker bees. In order to shed light on the evolution of JH signaling in bees we performed allatectomy and replacement therapies to manipulate JH levels in workers of the "primitively eusocial" bumblebee Bombus terrestris. Allatectomized worker bees showed remarkable reduction in ovarian development, egg laying, Vitellogenin and Krüppel homolog 1 fat body transcript levels, hemolymph Vitellogenin protein abundance, wax secretion, and egg-cell construction. These effects were reverted, at least partially, by treating allatectomized bees with JH-III, the natural JH of bees. Allatectomy also affected the amount of ester component in Dufour's gland secretion, which is thought to convey a social signal relating to worker fertility. These findings provide a strong support for the hypothesis that in contrast to honey bees, JH is a gonadotropin in bumblebees and lend credence to the hypothesis that the evolution of advanced eusociality in honey bees was associated with major modifications in JH signaling.

  2. Bombus haematurus (Hymenoptera: Apidae), new species in the Slovenian bumblebee fauna: Bombus haematurus (Hymenoptera: Apidae), nova vrsta v slovenski favni čmrljev:

    OpenAIRE

    GOGALA, Andrej; Grad, Janez; Jenič, Aljaž

    2010-01-01

    Records of Bombus haematurus, a new species in the Slovenian bumblebee fauna,are presented. The distribution of the species, its expansion towards the north west and possible implications are discussed.

  3. Fitness club

    CERN Multimedia

    Fitness club

    2013-01-01

    Nordic Walking Classes New session of 4 classes of 1 hour each will be held on Tuesdays in May 2013. Meet at the CERN barracks parking at Entrance A, 10 minutes before class time. Dates and time: 07.05, 14.05, 21.05 and 28.05, fom  12 h 30 to 13 h 30 Prices: 40 CHF per session + 10 CHF club membership – 5 CHF / hour pole rental Check out our schedule and enroll at http://cern.ch/club-fitness Hope to see you among us! 

  4. Information use in colonial living.

    Science.gov (United States)

    Evans, Julian C; Votier, Stephen C; Dall, Sasha R X

    2016-08-01

    Despite the fact that many animals live in groups, there is still no clear consensus about the ecological or evolutionary mechanisms underlying colonial living. Recently, research has suggested that colonies may be important as sources of social information. The ready availability of information from conspecifics allows animals to make better decisions about avoiding predators, reducing brood parasitism, migratory phenology, mate choice, habitat choice and foraging. These choices can play a large part in the development and maintenance of colonies. Here we review the types of information provided by colonial animals and examine the different ways in which decision-making in colonies can be enhanced by social information. We discuss what roles information might take in the evolution, formation and maintenance of colonies. In the process, we illustrate that information use permeates all aspects of colonial living. PMID:25882618

  5. Selective sweeps in growing microbial colonies

    International Nuclear Information System (INIS)

    Evolutionary experiments with microbes are a powerful tool to study mutations and natural selection. These experiments, however, are often limited to the well-mixed environments of a test tube or a chemostat. Since spatial organization can significantly affect evolutionary dynamics, the need is growing for evolutionary experiments in spatially structured environments. The surface of a Petri dish provides such an environment, but a more detailed understanding of microbial growth on Petri dishes is necessary to interpret such experiments. We formulate a simple deterministic reaction–diffusion model, which successfully predicts the spatial patterns created by two competing species during colony expansion. We also derive the shape of these patterns analytically without relying on microscopic details of the model. In particular, we find that the relative fitness of two microbial strains can be estimated from the logarithmic spirals created by selective sweeps. The theory is tested with strains of the budding yeast Saccharomyces cerevisiae for spatial competitions with different initial conditions and for a range of relative fitnesses. The reaction–diffusion model also connects the microscopic parameters like growth rates and diffusion constants with macroscopic spatial patterns and predicts the relationship between fitness in liquid cultures and on Petri dishes, which we confirmed experimentally. Spatial sector patterns therefore provide an alternative fitness assay to the commonly used liquid culture fitness assays. (paper)

  6. Food and Coloniality

    Directory of Open Access Journals (Sweden)

    Adolfo Albán Achinte

    2011-05-01

    Full Text Available The author tackles the alimentary dimension of life, as something that goes beyond the simple act of ingesting food to acquire nutrients, to concentrate on the cultural implications of eating. To eat is more than to feed oneself, for eating is never by itself a wholly innocent act; that is, eating is never completely stripped from the social relationships of those gathered around a table.From this perspective, the article examines coloniality in all its forms (of power, of knowledge and of being, and shows their function as mechanisms of both alimentary enunciation and classification, that are responsible of the gastronomic supplantation of produce and food from the New World with the goods and customs that were so dear to European settlers (not forgetting that the influx of products and seasonings went also in the other direction. The colonizing project included thus, besides its religious, political and administrative pretenses, a gastronomical element, to be found in the eagerness of the colonizers to reproduce the alimentary imprint of their homeland in the new found territories, at least as far as the circumstances and the climate allowed it. Among all the facets the production of knowledge can acquire, gastronomy has been poorly studied —not to say completely silenced— in its role as a token of cultural divides, in which a coloniality of flavors and palates has been carried out.

  7. Dutch Colonial Nostalgia Across Decolonisation

    OpenAIRE

    Bijl, P.

    2013-01-01

    This article argues that nostalgia for colonialism in the Netherlands, the so called tempo doeloe culture, is not a specifically postcolonial phenomenon caused by the collapse of the Dutch empire in Asia. In fact, nostalgia for the Dutch East Indies can be traced back to the nineteenth century, when the colony was still being formed, and its current form can productively be described as a nostalgia for nostalgia. On a more general level, colonial nostalgia, which is often too easily dismissed...

  8. Genetic variability of the neogregarine Apicystis bombi, an etiological agent of an emergent bumblebee disease.

    Science.gov (United States)

    Maharramov, Jafar; Meeus, Ivan; Maebe, Kevin; Arbetman, Marina; Morales, Carolina; Graystock, Peter; Hughes, William O H; Plischuk, Santiago; Lange, Carlos E; de Graaf, Dirk C; Zapata, Nelson; de la Rosa, Jose Javier Perez; Murray, Tomás E; Brown, Mark J F; Smagghe, Guy

    2013-01-01

    The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera) and bumblebee species (Bombus terrestris and Bombus ruderatus) in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii). In this study we investigated whether A. bombi is acting as an emergent parasite in the non-native populations. Specifically, we asked whether A. bombi, recently identified in Argentina, was introduced by European, non-native bees. Using ITS1 and ITS2 to assess the parasite's intraspecific genetic variation in bees from Argentina and Europe, we found a largely unstructured parasite population, with only 15% of the genetic variation being explained by geographic location. The most abundant haplotype in Argentina (found in all 9 specimens of non-native species) was identical to the most abundant haplotype in Europe (found in 6 out of 8 specimens). Similarly, there was no evidence of structuring by host species, with this factor explaining only 17% of the genetic variation. Interestingly, parasites in native Bombus ephippiatus from Mexico were genetically distant from the Argentine and European samples, suggesting that sufficient variability does exist in the ITS region to identify continent-level genetic structure in the parasite. Thus, the data suggest that A. bombi from Argentina and Europe share a common, relatively recent origin. Although our data did not provide information on the direction of transfer, the absence of genetic structure across space and host species suggests that A. bombi may be acting as an emergent infectious disease across bee taxa and continents. PMID:24324696

  9. Genetic variability of the neogregarine Apicystis bombi, an etiological agent of an emergent bumblebee disease.

    Directory of Open Access Journals (Sweden)

    Jafar Maharramov

    Full Text Available The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera and bumblebee species (Bombus terrestris and Bombus ruderatus in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii. In this study we investigated whether A. bombi is acting as an emergent parasite in the non-native populations. Specifically, we asked whether A. bombi, recently identified in Argentina, was introduced by European, non-native bees. Using ITS1 and ITS2 to assess the parasite's intraspecific genetic variation in bees from Argentina and Europe, we found a largely unstructured parasite population, with only 15% of the genetic variation being explained by geographic location. The most abundant haplotype in Argentina (found in all 9 specimens of non-native species was identical to the most abundant haplotype in Europe (found in 6 out of 8 specimens. Similarly, there was no evidence of structuring by host species, with this factor explaining only 17% of the genetic variation. Interestingly, parasites in native Bombus ephippiatus from Mexico were genetically distant from the Argentine and European samples, suggesting that sufficient variability does exist in the ITS region to identify continent-level genetic structure in the parasite. Thus, the data suggest that A. bombi from Argentina and Europe share a common, relatively recent origin. Although our data did not provide information on the direction of transfer, the absence of genetic structure across space and host species suggests that A. bombi may be acting as an emergent infectious disease across bee taxa and continents.

  10. Unsteady aerodynamic forces and power requirements of a bumblebee in forward flight

    Institute of Scientific and Technical Information of China (English)

    Jianghao Wu; Mao Sun

    2005-01-01

    Aerodynamic forces and power requirements in forward flight in a bumblebee (Bombus terrestris) were studied using the method of computational fluid dynamics. Actual wing kinematic data of free flight were used in the study (the speed ranges from 0 m/s to 4.5 m/s; advance ratio ranges from 0-0.66). The bumblebee employs the delayed stall mechanism and the fast pitching-up rotation mechanism to produce vertical force and thrust. The leading-edge vortex does not shed in the translatory phase of the half-strokes and is much more concentrated than that of the fruit fly in a previous study. At hovering and low-speed flight, the vertical force is produced by both the half-strokes and is contributed by wing lift; at medium and high speeds, the vertical force is mainly produced during the downstroke and is contributed by both wing lift and wing drag. At all speeds the thrust is mainly produced in the upstroke and is contributed by wing drag.The power requirement at low to medium speeds is not very different from that of hovering and is relatively large at the highest speed (advance ratio 0.66), i.e. the power curve is Jshaped. Except at the highest flight speed, storing energy elastically can save power up to 20%-30%. At the highest speed,because of the large increase of aerodynamic torque and the slight decrease of inertial torque (due to the smaller stroke amplitude and stroke frequency used), the power requirement is dominated by aerodynamic power and the effect of elastic storage of energy on power requirement is limited.

  11. Displacement of a native by an alien bumblebee: lower pollinator efficiency overcome by overwhelmingly higher visitation frequency.

    Science.gov (United States)

    Madjidian, Josefin A; Morales, Carolina L; Smith, Henrik G

    2008-07-01

    Biological invasions might constitute a major threat to mutualisms. Introduced pollinators might competitively displace their native counterparts, which in turn affects the pollination of native plants, if native and alien visitors differ in pollinator effectiveness. Since its invasion in 1994 into south-west Argentina, the introduced European bumblebee Bombus ruderatus has continuously increased in abundance, along with a simultaneous decrease in the abundance of the native Bombus dahlbomii. The latter is the only native bumblebee species of the temperate forests of southern South America, and the main pollinator of the endemic herb Alstroemeria aurea. In order to evaluate the impact of the ongoing displacement of the native by the alien bumblebee, we compared the pollinator effectiveness (i.e., the combination of pollinator efficiency per visit and visitation frequency) between both bumblebee species, as well as related pollinator traits that might account for potential differences in pollinator efficiency. Native Bombus dahlbomii, which has a larger body and spent more time per flower, was the more efficient pollinator compared to Bombus ruderatus, both in terms of quantity and quality of pollen deposited per visit. However, Bombus ruderatus was a much more frequent flower visitor than Bombus dahlbomii. As a consequence, Bombus ruderatus is nowadays a more effective pollinator of A. aurea than its native congener. Despite the lack of evidence of an increase in seed set at the population level, comparisons with historical records of Bombus dahlbomii abundances prior to Bombus ruderatus' invasion suggest that the overall pollination intensity of A. aurea might in fact have risen as a consequence of this invasion. Field experiments like these, that incorporate the natural variation in abundance of native and alien species, are powerful means to demonstrate that the consequences of invasions are more complex than previous manipulated and controlled experiments have

  12. Floral scent variation in two Antirrhinum majus subspecies influences the choice of naïve bumblebees

    OpenAIRE

    Dormont, Laurent; Schatz, Bertrand; Giurfa, Martin; Simon, Valérie; Raynaud, Christine; Chave, Jérôme

    2011-01-01

    Two wild subspecies of snapdragon, Antirrhinum majus, subspecies pseudomajus and striatum, differ in floral color and can be visually discriminated by insect visitors. The extent to which olfactory cues derived from floral scents contribute to discrimination between snapdragon subspecies is however unknown. We tested whether these two subspecies differ in floral scent and whether these olfactory differences are used by bumblebees (Bombus terrestris) to discriminate between them. We grew indiv...

  13. Recognition and identification of bumblebee species in the Bombus lucorum-complex (Hymenoptera, Apidae) – A review and outlook

    OpenAIRE

    Bossert,Silas

    2015-01-01

    The recognition of cryptic species represents one of the major challenges in current taxonomy and affects our understanding of global diversity. In practice, the process from discovery to acceptance in the scientific community can take an extensive length of time. A prime example is the traditionally difficult taxonomy of the cryptic bumblebee species belonging to the Bombus lucorum-complex. The status of the three European species in the group – Bombus lucorum and the closely related Bombus ...

  14. The influence of pigmentation patterning on bumblebee foraging from flowers of Antirrhinum majus

    OpenAIRE

    Whitney, Heather M; Milne, Georgina; Rands, Sean A; Vignolini, Silvia; Martin, Cathie; Glover, Beverley J

    2013-01-01

    Patterns of pigmentation overlying the petal vasculature are common in flowering plants,and have been postulated to play a role in pollinator attraction. Previous studies report that such venation patterning is significantly more attractiveto bee foragers in the field than ivory or white flowers without veins. To dissect the ways in which venation patterning of pigment can influence bumblebee behaviour we investigated the response of flower-naïve individuals of Bombus terrestris to veined, iv...

  15. Habitat assessment ability of bumble-bees implies frequency-dependent selection on floral rewards and display size

    OpenAIRE

    Biernaskie, Jay M; Gegear, Robert J

    2007-01-01

    Foraging pollinators could visit hundreds of flowers in succession on mass-flowering plants, yet they often visit only a small number—potentially saving the plant from much self-pollination among its own flowers (geitonogamy). This study tests the hypothesis that bumble-bee (Bombus impatiens) residence on a particular plant depends on an assessment of that plant's reward value relative to the overall quality experienced in the habitat. In a controlled environment, naive bees were given experi...

  16. Highly efficient pollination by bumblebees ensures seed production in Pedicularis lachnoglossa (Orobanchaceae), an early-flowering Himalayan plant

    Institute of Scientific and Technical Information of China (English)

    Wen-Bin YU; De-Zhu LI; Hong WANG

    2012-01-01

    Pedicularis (Orobranchaceae) is a common high altitude genus of the Himalayas that may be affected by pollination limitation.Using Pedicularis lachnoglossa from Yulong (Jade Dragon) Snow Mountain in Lijiang (Yunnan Province,southwest China),we investigated the effects of high altitude habitats on the process of pollination and seed production.Floral biology,pollinator foraging behavior,breeding system,and pollination efficiency were examined using observation and exclusionary techniques.Pedicularis lachnoglossa was found to be entomophilous and exclusively pollinated by Bombusfriseanus and B.yunnanicola.Our results indicated that pollination limitation in P.lachnoglossa was not significant.Under open pollination,approximately 80% of flowers were successfully pollinated and developed to fruits,and about 38% of ovules developed to mature seeds.Bumblebee pollination is highly precise and efficient in P lachnoglossa,because its flowering phenology and floral characters enhance the foraging of bumblebees on flowers.This study supports that animal pollination plays a crucial role in the outbreeding of the early flowering Pedicularis.The evolution of floral specification in Pedicularis has the advantages of adaptation to bumblebee pollination in adverse high altitude habitats.

  17. South American native bumblebees (Hymenoptera: Apidae) infected by Nosema ceranae (Microsporidia), an emerging pathogen of honeybees (Apis mellifera).

    Science.gov (United States)

    Plischuk, Santiago; Martín-Hernández, Raquel; Prieto, Lourdes; Lucía, Mariano; Botías, Cristina; Meana, Aránzazu; Abrahamovich, Alberto H; Lange, Carlos; Higes, Mariano

    2009-04-01

    As pollination is a critical process in both human-managed and natural terrestrial ecosystems, pollinators provide essential services to both nature and humans. Pollination is mainly due to the action of different insects, such as the bumblebee and the honeybee. These important ecological and economic roles have led to widespread concern over the recent decline in pollinator populations that has been detected in many regions of the world. While this decline has been attributed in some cases to changes in the use of agricultural land, the effects of parasites could play a significant role in the reduction of these populations. For the first time, we describe here the presence of Nosema ceranae, an emerging honeybee pathogen, in three species of Argentine native bumblebees. A total of 455 bumblebees belonging to six species of genus Bombus were examined. PCR results showed that three of the species are positive to N. ceranae (Bombus atratus, Bombus morio and Bombus bellicosus). We discuss the appearance of this pathogen in the context of the population decline of this pollinators. PMID:23765744

  18. Colony Variation in Staphylococcus lugdunensis

    OpenAIRE

    Leung, Michael J.; Nuttall, Nichalas; Pryce, Todd M.; Coombs, Geoffrey W; Pearman, John W.

    1998-01-01

    Staphylococcus lugdunensis is being increasingly reported as a pathogen with an outcome resembling that of S. aureus rather than coagulase-negative staphylococci. Recent local isolates exhibited colonial variation that delayed identification and interpretation of clinical significance. Until now previous descriptions have not emphasized colonial variation as an important identifying characteristic of S. lugdunensis.

  19. Student Discipline in Colonial America.

    Science.gov (United States)

    Petry, John R.

    The basis for the severe discipline imposed on school children in colonial America, especially in the Puritan colonies, was the belief in original sin. The child was regarded as being born in sin and thus depraved and prone to sin. The purpose of education was to enable children to read the Bible and thus change the behavior which otherwise would…

  20. Colony fusion and worker reproduction after queen loss in army ants

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; Schöning, Caspar; d'Ettorre, Patrizia;

    2010-01-01

    Theory predicts that altruism is only evolutionarily stable if it is preferentially directed towards relatives, so that any such behaviour towards seemingly unrelated individuals requires scrutiny. Queenless army ant colonies, which have anecdotally been reported to fuse with queenright foreign...... colonies, are such an enigmatic case. Here we combine experimental queen removal with population genetics and cuticular chemistry analyses to show that colonies of the African army ant Dorylus molestus frequently merge with neighbouring colonies after queen loss. Merging colonies often have no direct co......-ancestry, but are on average probably distantly related because of overall population viscosity. The alternative of male production by orphaned workers appears to be so inefficient that residual inclusive fitness of orphaned workers might be maximized by indiscriminately merging with neighbouring colonies to...

  1. Mechanisms of social regulation change across colony development in an ant

    Directory of Open Access Journals (Sweden)

    Liebig Jürgen

    2010-10-01

    Full Text Available Abstract Background Mutual policing is an important mechanism for reducing conflict in cooperative groups. In societies of ants, bees, and wasps, mutual policing of worker reproduction can evolve when workers are more closely related to the queen's sons than to the sons of workers or when the costs of worker reproduction lower the inclusive fitness of workers. During colony growth, relatedness within the colony remains the same, but the costs of worker reproduction may change. The costs of worker reproduction are predicted to be greatest in incipient colonies. If the costs associated with worker reproduction outweigh the individual direct benefits to workers, policing mechanisms as found in larger colonies may be absent in incipient colonies. Results We investigated policing behaviour across colony growth in the ant Camponotus floridanus. In large colonies of this species, worker reproduction is policed by the destruction of worker-laid eggs. We found workers from incipient colonies do not exhibit policing behaviour, and instead tolerate all conspecific eggs. The change in policing behaviour is consistent with changes in egg surface hydrocarbons, which provide the informational basis for policing; eggs laid by queens from incipient colonies lack the characteristic hydrocarbons on the surface of eggs laid by queens from large colonies, making them chemically indistinguishable from worker-laid eggs. We also tested the response to fertility information in the context of queen tolerance. Workers from incipient colonies attacked foreign queens from large colonies; whereas workers from large colonies tolerated such queens. Workers from both incipient and large colonies attacked foreign queens from incipient colonies. Conclusions Our results provide novel insights into the regulation of worker reproduction in social insects at both the proximate and ultimate levels. At the proximate level, our results show that mechanisms of social regulation, such as

  2. Bumblebee Killer

    OpenAIRE

    Rosengren, Per; Nilsson, Andreas

    1999-01-01

    A common problem in GSM terminals is an interfering signal nicknamed the “Bumblebee”. This interference is generated by the switching nature of TDMA cellular telephony, the radio circuits are switched on and off with the radio access rate. In GSM, this frequency is approximately 217 Hz, This frequency and its harmonics get into the analog microphone signal, and produce a very annoying periodic noise in the uplink speech. This thesis contains a study of four differerent software solutions, to ...

  3. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Science.gov (United States)

    Tarpy, David R.; vanEngelsdorp, Dennis; Pettis, Jeffrey S.

    2013-08-01

    Honey bee ( Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency ( m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated.

  4. Colonial Figures: Memories of Street Traders in the Colonial and Early Post-colonial Periods

    Directory of Open Access Journals (Sweden)

    Sheri Lynn Gibbings

    2012-12-01

    Full Text Available This article explores post-colonial memories about street traders among individuals who lived in the former colony of the Dutch East Indies. It argues that these narratives romanticize the relationship between Europeans and indigenous peoples. Street vendors are also used to differentiate between periods within colonial and post-colonial history. The nostalgic representation of interracial contact between Europeans and traders is contrasted with representations of other figures such as the Japanese and the nationalist. A recurring feature of these representations is the ability of Europeans to speak with street traders and imagine what they wanted and needed. The traders are remembered as a social type that transgressed politics and represented the neutrality of the economic sphere as a place for shared communication. The article concludes that the figure of the street vendor contributes to the nostalgic reinvention of the colony but is also used in narratives to differentiate between and mark changes across the colonial and post-colonial periods.

  5. Indians and Southern Colonial Statutes

    Science.gov (United States)

    Kawashima, Yasuhide

    1974-01-01

    Southern statutes, with their dual nature of uniformity and diversity, were doubtlessly an essential source of law for the examination of complex legal relations between American Indians and Anglo Americans in the colonial South. (FF)

  6. A protocol to assess insect resistance to heat waves, applied to bumblebees (Bombus Latreille, 1802.

    Directory of Open Access Journals (Sweden)

    Baptiste Martinet

    Full Text Available Insect decline results from numerous interacting factors including climate change. One of the major phenomena related to climate change is the increase of the frequency of extreme events such as heat waves. Since heat waves are suspected to dramatically increase insect mortality, there is an urgent need to assess their potential impact. Here, we determined and compared the resistance to heat waves of insects under hyperthermic stress through their time before heat stupor (THS when they are exposed to an extreme temperature (40°C. For this, we used a new experimental standardised device available in the field or in locations close to the field collecting sites. We applied this approach on different Arctic, Boreo-Alpine and Widespread bumblebee species in order to predict consequences of heat waves. Our results show a heat resistance gradient: the heat stress resistance of species with a centred arctic distribution is weaker than the heat resistance of the Boreo-Alpine species with a larger distribution which is itself lower than the heat stress resistance of the ubiquitous species.

  7. Rainwater in cupulate bracts repels seed herbivores in a bumblebee-pollinated subalpine flower.

    Science.gov (United States)

    Sun, Shi-Guo; Huang, Shuang-Quan

    2015-01-01

    Floral herbivory may have deleterious effects on the reproductive success of flowering plants. However, plants may evolve floral traits that allow them to defend against herbivory in particular conditions. A bumblebee-pollinated subalpine herb, Pedicularis rex (Orobanchaceae), endemic to southwest China, has cup-like bracts that fill with rainwater, which submerges its corolla tubes. We hypothesized that these water-filled cupulate bracts function to deter nectar robbers and/or seed herbivores. To test these hypotheses, we experimentally drained bracts and measured both the response of mutualistic floral visitors and antagonistic nectar robbers and seed predators and their effects on seed production. Our observations revealed that neither nectar robbers nor legitimate pollinators discriminated between water-drained flowers and intact controls. However, seed predation significantly increased in drained flowers, suggesting that water-filled bracts help protect the flowers from seed herbivores. The water-filled bracts in P. rex may represent an adaptation to reduce floral herbivory in a high-rainfall environment. PMID:25762460

  8. Expression profile of the sex determination gene doublesex in a gynandromorph of bumblebee, Bombus ignitus

    Science.gov (United States)

    Ugajin, Atsushi; Matsuo, Koshiro; Kubo, Ryohei; Sasaki, Tetsuhiko; Ono, Masato

    2016-04-01

    Gynandromorphy that has both male and female features is known in many insect orders, including Hymenoptera. In most cases, however, only external morphology and behavioral aspects have been studied. We found a gynandromorph of bumblebee, Bombus ignitus, that showed almost bilateral distribution of external sexual traits, with male characters observed on the left side and female characters on the right side. This individual never exhibited sexual behavior toward new queens. The dissection of the head part showed that it had bilaterally dimorphic labial glands, only the left of which was well developed and synthesized male-specific pheromone components. In contrast, the gynandromorph possessed an ovipositor and a pair of ovaries in the abdominal part, suggesting that it had a uniformly female reproductive system. Furthermore, we characterized several internal organs of the gynandromorph by a molecular biological approach. The expression analyses of a sex determination gene, doublesex, in the brain, the fat bodies, the hindgut, and the ovaries of the gynandromorph revealed a male-type expression pattern exclusively in the left brain hemisphere and consistent female-type expression in other tissues. These findings clearly indicate the sexual discordance between external traits and internal organs in the gynandromorph. The results of genetic analyses using microsatellite markers suggested that this individual consisted of both genetically male- and female-type tissues.

  9. Signatures of a globally optimal searching strategy in the three-dimensional foraging flights of bumblebees.

    Science.gov (United States)

    Lihoreau, Mathieu; Ings, Thomas C; Chittka, Lars; Reynolds, Andy M

    2016-01-01

    Simulated annealing is a powerful stochastic search algorithm for locating a global maximum that is hidden among many poorer local maxima in a search space. It is frequently implemented in computers working on complex optimization problems but until now has not been directly observed in nature as a searching strategy adopted by foraging animals. We analysed high-speed video recordings of the three-dimensional searching flights of bumblebees (Bombus terrestris) made in the presence of large or small artificial flowers within a 0.5 m(3) enclosed arena. Analyses of the three-dimensional flight patterns in both conditions reveal signatures of simulated annealing searches. After leaving a flower, bees tend to scan back-and forth past that flower before making prospecting flights (loops), whose length increases over time. The search pattern becomes gradually more expansive and culminates when another rewarding flower is found. Bees then scan back and forth in the vicinity of the newly discovered flower and the process repeats. This looping search pattern, in which flight step lengths are typically power-law distributed, provides a relatively simple yet highly efficient strategy for pollinators such as bees to find best quality resources in complex environments made of multiple ephemeral feeding sites with nutritionally variable rewards. PMID:27459948

  10. Pollen foraging: learning a complex motor skill by bumblebees (Bombus terrestris)

    Science.gov (United States)

    Raine, Nigel E.; Chittka, Lars

    2007-06-01

    To investigate how bumblebees (Bombus terrestris) learn the complex motor skills involved in pollen foraging, we observed naïve workers foraging on arrays of nectarless poppy flowers (Papaver rhoeas) in a greenhouse. Foraging skills were quantified by measuring the pollen load collected during each foraging bout and relating this to the number of flowers visited and bout duration on two consecutive days. The pollen standing crop (PSC) in each flower decreased drastically from 0530 to 0900 hours. Therefore, we related foraging performance to the changing levels of pollen available (per flower) and found that collection rate increased over the course of four consecutive foraging bouts (comprising between 277 and 354 individual flower visits), suggesting that learning to forage for pollen represents a substantial time investment for individual foragers. The pollen collection rate and size of pollen loads collected at the start of day 2 were markedly lower than at the end of day 1, suggesting that components of pollen foraging behaviour could be subject to imperfect overnight retention. Our results suggest that learning the necessary motor skills to collect pollen effectively from morphologically simple flowers takes three times as many visits as learning how to handle the most morphologically complex flowers to extract nectar, potentially explaining why bees are more specialised in their choice of pollen flowers.

  11. The influence of pigmentation patterning on bumblebee foraging from flowers of Antirrhinum majus

    Science.gov (United States)

    Whitney, Heather M.; Milne, Georgina; Rands, Sean A.; Vignolini, Silvia; Martin, Cathie; Glover, Beverley J.

    2013-03-01

    Patterns of pigmentation overlying the petal vasculature are common in flowering plants and have been postulated to play a role in pollinator attraction. Previous studies report that such venation patterning is significantly more attractive to bee foragers in the field than ivory or white flowers without veins. To dissect the ways in which venation patterning of pigment can influence bumblebee behaviour, we investigated the response of flower-naïve individuals of Bombus terrestris to veined, ivory and red near-isogenic lines of Antirrhinum majus. We find that red venation shifts flower colour slightly, although the ivory background is the dominant colour. Bees were readily able to discriminate between ivory and veined flowers under differential conditioning but showed no innate preference when presented with a free choice of rewarding ivory and veined flowers. In contrast, both ivory and veined flowers were selected significantly more often than were red flowers. We conclude that advantages conferred by venation patterning might stem from bees learning of their use as nectar guides, rather than from any innate preference for striped flowers.

  12. Species differences in bumblebee immune response predict developmental success of a parasitoid fly.

    Science.gov (United States)

    Davis, Staige E; Malfi, Rosemary L; Roulston, T'ai H

    2015-08-01

    Endoparasitoids develop inside the body of a host organism and, if successful, eventually kill their host in order to reach maturity. Host species can vary in their suitability for a developing endoparasitoid; in particular, the host immune response, which can suppress egg hatching and larval development, has been hypothesized to be one of the most important determinants of parasitoid host range. In this study, we investigated whether three bumblebee host species (Bombus bimaculatus, Bombus griseocollis, and Bombus impatiens) varied in their suitability for the development of a shared parasitoid, the conopid fly (Conopidae, Diptera) and whether the intensity of host encapsulation response, an insect immune defense against invaders, could predict parasitoid success. When surgically implanted with a nylon filament, B. griseocollis exhibited a stronger immune response than both B. impatiens and B. bimaculatus. Similarly, B. griseocollis was more likely to melanize conopid larvae from natural infections and more likely to kill conopids prior to its own death. Our results indicate that variation in the strength of the general immune response of insects may have ecological implications for sympatric species that share parasites. We suggest that, in this system, selection for a stronger immune response may be heightened by the pattern of phenological overlap between local host species and the population peak of their most prominent parasitoid. PMID:25795253

  13. Immune response and gut microbial community structure in bumblebees after microbiota transplants.

    Science.gov (United States)

    Näpflin, Kathrin; Schmid-Hempel, Paul

    2016-05-25

    Microbial communities are a key component of host health. As the microbiota is initially 'foreign' to a host, the host's immune system should respond to its acquisition. Such variation in the response should relate not only to host genetic background, but also to differences in the beneficial properties of the microbiota. However, little is known about such interactions. Here, we investigate the gut microbiota of the bumblebee, Bombus terrestris, which has a protective function against the bee's natural trypanosome gut parasite, Crithidia bombi We transplanted 'resistant' and 'susceptible' microbiota into 'resistant' and 'susceptible' host backgrounds, and studied the activity of the host immune system. We found that bees from different resistance backgrounds receiving a microbiota differed in aspects of their immune response. At the same time, the elicited immune response also depended on the received microbiota's resistance phenotype. Furthermore, the microbial community composition differed between microbiota resistance phenotypes (resistant versus susceptible). Our results underline the complex feedback between the host's ability to potentially exert selection on the establishment of a microbial community and the influence of the microbial community on the host immune response in turn. PMID:27226466

  14. Portable digital video surveillance system for monitoring flower-visiting bumblebees

    Directory of Open Access Journals (Sweden)

    Thorsdatter Orvedal Aase, Anne Lene

    2011-08-01

    Full Text Available In this study we used a portable event-triggered video surveillance system for monitoring flower-visiting bumblebees. The system consist of mini digital recorder (mini-DVR with a video motion detection (VMD sensor which detects changes in the image captured by the camera, the intruder triggers the recording immediately. The sensitivity and the detection area are adjustable, which may prevent unwanted recordings. To our best knowledge this is the first study using VMD sensor to monitor flower-visiting insects. Observation of flower-visiting insects has traditionally been monitored by direct observations, which is time demanding, or by continuous video monitoring, which demands a great effort in reviewing the material. A total of 98.5 monitoring hours were conducted. For the mini-DVR with VMD, a total of 35 min were spent reviewing the recordings to locate 75 pollinators, which means ca. 0.35 sec reviewing per monitoring hr. Most pollinators in the order Hymenoptera were identified to species or group level, some were only classified to family (Apidae or genus (Bombus. The use of the video monitoring system described in the present paper could result in a more efficient data sampling and reveal new knowledge to pollination ecology (e.g. species identification and pollinating behaviour.

  15. Comparative flight morphology in queens of invasive and native Patagonian bumblebees (Hymenoptera: Bombus).

    Science.gov (United States)

    Polidori, Carlo; Nieves-Aldrey, José Luis

    2015-02-01

    Since its introduction in Chile, the European Bombus terrestris L. (Hymenoptera: Apidae) has progressively reduced the abundance of the native Patagonian bumblebee, Bombus dahlbomii Guérin. Because an important cause of successful invasion of a species may depend on a potentially advantageous phenotype, we studied morphologies related to flight performance (flight muscle ratio (FMR), wing loading (WL), excess power index (EPI, which integrates FMR and WL) and wing aspect ratio (AR)) in the queens of the two species. Previous empirical studies showed that greater FMR, AR and EPI, and lower WL increase flight performance. In the Patagonian Chilean fjord where the study was carried out, B. dahlbomii was 40% heavier than B. terrestris, a difference theoretically allowing the queens of the native species to take off with heavier loads, despite the fact that the two species have virtually identical FMRs. However, FMR negatively depended on body mass at the intra-specific level. The total wing area was 35% greater in B. dahlbomii, but the difference in forewing length was only of 16%. Once taken into account the effect of body size, WL, was significantly lower in B. terrestris. AR increased with body mass and did not differ between species. EPI was weakly but significantly higher in B. terrestris. Experiments formally linking such parameters with flight performance may help to explain the observed quick and wide spread of this alien species in Patagonia in the last few years. PMID:25499798

  16. The invasion of southern South America by imported bumblebees and associated parasites.

    Science.gov (United States)

    Schmid-Hempel, Regula; Eckhardt, Michael; Goulson, David; Heinzmann, Daniel; Lange, Carlos; Plischuk, Santiago; Escudero, Luisa R; Salathé, Rahel; Scriven, Jessica J; Schmid-Hempel, Paul

    2014-07-01

    The Palaearctic Bombus ruderatus (in 1982/1983) and Bombus terrestris (1998) have both been introduced into South America (Chile) for pollination purposes. We here report on the results of sampling campaigns in 2004, and 2010-2012 showing that both species have established and massively expanded their range. Bombus terrestris, in particular, has spread by some 200 km year(-1) and had reached the Atlantic coast in Argentina by the end of 2011. Both species, and especially B. terrestris, are infected by protozoan parasites that seem to spread along with the imported hosts and spillover to native species. Genetic analyses by polymorphic microsatellite loci suggest that the host population of B. terrestris is genetically diverse, as expected from a large invading founder population, and structured through isolation by distance. Genetically, the populations of the trypanosomatid parasite, Crithidia bombi, sampled in 2004 are less diverse, and distinct from the ones sampled later. Current C. bombi populations are highly heterozygous and also structured through isolation by distance correlating with the genetic distances of B. terrestris, suggesting the latter's expansion to be a main structuring factor for the parasite. Remarkably, wherever B. terrestris spreads, the native Bombus dahlbomii disappears although the reasons remain unclear. Our ecological and genetic data suggest a major invasion event that is currently unfolding in southern South America with disastrous consequences for the native bumblebee species. PMID:24256429

  17. Visual targeting of components of floral colour patterns in flower-naïve bumblebees ( Bombus terrestris; Apidae)

    Science.gov (United States)

    Lunau, Klaus; Fieselmann, Gabriele; Heuschen, Britta; van de Loo, Antje

    2006-07-01

    Floral colour patterns are contrasting colour patches on flowers, a part of the signalling apparatus that was considered to display shape and colour signals used by flower-visitors to detect flowers and locate the site of floral reward. Here, we show that flower-naïve bumblebees ( Bombus terrestris) spontaneously direct their approach towards the outside margin of artificial flowers, which provides contrast between these dummy flowers and the background. If no floral guides are present, the bumblebees continue to approach the margin and finally touch the marginal area of the dummy flower with the tips of their antennae. Whilst approaching dummy flowers that also have a central floral guide, the bumblebees change their direction of flight: Initially, they approach the margin, later they switch to approaching the colour guide, and finally they precisely touch the floral guide with their antennae. Variation of the shape of equally sized dummy flowers did not alter the bumblebees’ preferential orientation towards the guide. Using reciprocal combinations of guide colour and surrounding colour, we showed that the approach from a distance towards the corolla and the antennal contact with the guide are elicited by the same colour parameter: spectral purity. As a consequence, the dummy flowers eliciting the greatest frequency of antennal reactions at the guide are those that combine a floral guide of high spectral purity with a corolla of less spectral purity. Our results support the hypothesis that floral guides direct bumblebees’ approaches to the site of first contact with the flower, which is achieved by the tips of the antennae.

  18. The neonicotinoid pesticide, imidacloprid, affects Bombus impatiens (bumblebee) sonication behavior when consumed at doses below the LD50.

    Science.gov (United States)

    Switzer, Callin M; Combes, Stacey A

    2016-08-01

    We investigated changes in sonication (or buzz-pollination) behavior of Bombus impatiens bumblebees, after consumption of the neonicotinoid pesticide, imidacloprid. We measured sonication frequency, sonication length, and flight (wing beat) frequency of marked bees collecting pollen from Solanum lycopsersicum (tomato), and then randomly assigned bees to consume 0, 0.0515, 0.515, or 5.15 ng of imidacloprid. We recorded the number of bees in each treatment group that resumed sonication behavior after consuming imidacloprid, and re-measured sonication and flight behavior for these bees. We did not find evidence that consuming 0.0515 ng imidacloprid affected the sonication length, sonication frequency, or flight frequency for bees that sonicated after consuming imidacloprid; we were unable to test changes in these variables for bees that consumed 0.515 or 5.15 ng because we did not observe enough of these bees sonicating after treatment. We performed Cox proportional hazard regression to determine whether consuming imidacloprid affected the probability of engaging in further sonication behavior on S. lycopersicum and found that bumblebees who consumed 0.515 or 5.15 ng of imidacloprid were significantly less likely to sonicate after treatment than bees who consumed no imidacloprid. At the end of the experiment, we classified bees as dead or alive; our data suggest a trend of increasing mortality with higher doses of imidacloprid. Our results show that even modest doses of imidacloprid can significantly affect the likelihood of bumblebees engaging in sonication, a behavior critical for the pollination of a variety of crops and other plants. PMID:27189613

  19. Pathogen Webs in Collapsing Honey Bee Colonies

    OpenAIRE

    Cornman, R Scott; Tarpy, David R.; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S.; vanEngelsdorp, Dennis; Jay D. Evans

    2012-01-01

    Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, ...

  20. Ant Colony Optimization: A Review and Comparison

    OpenAIRE

    Sundus Shaukat; Riaz Ahmed Bhatti; Khalid Ibrahim Qureshi; Shafqat Ali Shad

    2014-01-01

    Many optmization algorithms are developed over period of time, among these most famous and widely used is Ant Colony systems (ACA). Ant Colony Systems (ACS) are the collection of different ant colony optimization algorithms. Different algorithms are used for solve the Travelling salesmen Problem (TCP) but ant colony algorithm is more preferred to solve the travelling salesmen problem. In ant colony best solution is found with the help of cooperating agents called ants. Ants cooperate with eac...

  1. Personality, foraging and fitness consequences in a long lived seabird.

    Directory of Open Access Journals (Sweden)

    Samantha C Patrick

    Full Text Available While personality differences in animals are defined as consistent behavioural variation between individuals, the widely studied field of foraging specialisation in marine vertebrates has rarely been addressed within this framework. However there is much overlap between the two fields, both aiming to measure the causes and consequences of consistent individual behaviour. Here for the first time we use both a classic measure of personality, the response to a novel object, and an estimate of foraging strategy, derived from GPS data, to examine individual personality differences in black browed albatross and their consequences for fitness. First, we examine the repeatability of personality scores and link these to variation in foraging habitat. Bolder individuals forage nearer the colony, in shallower regions, whereas shyer birds travel further from the colony, and fed in deeper oceanic waters. Interestingly, neither personality score predicted a bird's overlap with fisheries. Second, we show that both personality scores are correlated with fitness consequences, dependent on sex and year quality. Our data suggest that shyer males and bolder females have higher fitness, but the strength of this relationship depends on year quality. Females who forage further from the colony have higher breeding success in poor quality years, whereas males foraging close to the colony always have higher fitness. Together these results highlight the potential importance of personality variation in seabirds and that the fitness consequences of boldness and foraging strategy may be highly sex dependent.

  2. Royal jelly-like protein localization reveals differences in hypopharyngeal glands buildup and conserved expression pattern in brains of bumblebees and honeybees

    Directory of Open Access Journals (Sweden)

    Štefan Albert

    2014-03-01

    Full Text Available Royal jelly proteins (MRJPs of the honeybee bear several open questions. One of them is their expression in tissues other than the hypopharyngeal glands (HGs, the site of royal jelly production. The sole MRJP-like gene of the bumblebee, Bombus terrestris (BtRJPL, represents a pre-diversification stage of the MRJP gene evolution in bees. Here we investigate the expression of BtRJPL in the HGs and the brain of bumblebees. Comparison of the HGs of bumblebees and honeybees revealed striking differences in their morphology with respect to sex- and caste-specific appearance, number of cells per acinus, and filamentous actin (F-actin rings. At the cellular level, we found a temporary F-actin-covered meshwork in the secretory cells, which suggests a role for actin in the biogenesis of the end apparatus in HGs. Using immunohistochemical localization, we show that BtRJPL is expressed in the bumblebee brain, predominantly in the Kenyon cells of the mushroom bodies, the site of sensory integration in insects, and in the optic lobes. Our data suggest that a dual gland-brain function preceded the multiplication of MRJPs in the honeybee lineage. In the course of the honeybee evolution, HGs dramatically changed their morphology in order to serve a food-producing function.

  3. Unraveling the venom proteome of the bumblebee (Bombus terrestris) by integrating a combinatorial peptide ligand library approach with FT-ICR MS.

    Science.gov (United States)

    Van Vaerenbergh, Matthias; Debyser, Griet; Smagghe, Guy; Devreese, Bart; de Graaf, Dirk C

    2015-08-01

    Within the Apidae, the largest family of bees with over 5600 described species, the honeybee is the sole species with a well studied venom proteome. So far, only little research has focused on bumblebee venom. Recently, the genome sequence of the European large earth bumblebee (Bombus terrestris) became available and this allowed the first in-depth proteomic analysis of its venom composition. We identified 57 compounds, with 52 of them never described in bumblebee venom. Remarkably, 72% of the detected compounds were found to have a honeybee venom homolog, which reflects the similar defensive function of both venoms and the high degree of homology between both genomes. However, both venoms contain a selection of species-specific toxins, revealing distinct damaging effects that may have evolved in response to species-specific attackers. Further, this study extends the list of potential venom allergens. The availability of both the honeybee and bumblebee venom proteome may help to develop a strategy that solves the current issue of false double sensitivity in allergy diagnosis, which is caused by cross-reactivity between both venoms. A correct diagnosis is important as it is recommended to perform an immunotherapy with venom of the culprit species. PMID:26071081

  4. Can winter-active bumblebees survive the cold? Assessing the cold tolerance of Bombus terrestris audax and the effects of pollen feeding.

    Directory of Open Access Journals (Sweden)

    Emily L Owen

    Full Text Available There is now considerable evidence that climate change is disrupting the phenology of key pollinator species. The recently reported UK winter activity of the bumblebee Bombus terrestris brings a novel set of thermal challenges to bumblebee workers that would typically only be exposed to summer conditions. Here we assess the ability of workers to survive acute and chronic cold stress (via lower lethal temperatures and lower lethal times at 0°C, the capacity for rapid cold hardening (RCH and the influence of diet (pollen versus nectar consumption on supercooling points (SCP. Comparisons are made with chronic cold stress indices and SCPs in queen bumblebees. Results showed worker bees were able to survive acute temperatures likely to be experienced in a mild winter, with queens significantly more tolerant to chronic cold temperature stress. The first evidence of RCH in any Hymenoptera is shown. In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature. These results are discussed in the light of winter active bumblebees and climate change.

  5. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  6. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Science.gov (United States)

    Honey bee (Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirica...

  7. Unge, sundhed og fitness

    DEFF Research Database (Denmark)

    Jensen, Jens-Ole

    2003-01-01

    Artiklen redegør for udbredelsen af fitness blandt unge og diskuterer, hvor det er blevet så populært at dyrke fitness.......Artiklen redegør for udbredelsen af fitness blandt unge og diskuterer, hvor det er blevet så populært at dyrke fitness....

  8. Control of flight forces and moments by flapping wings of model bumblebee

    Institute of Scientific and Technical Information of China (English)

    WU Jiang-hao; SUN Mao

    2008-01-01

    The control of flight forces and moments by flapping wings of a model bumblebee is studied using the method of computational fluid dynamics.Hovering flight is taken as the reference flight:Wing kinematic parameters are varied with respect to their values at hovering flight.Moments about(and forces along)x,y,z axes that pass the center of mass are computed.Changing stroke amplitude(or wingbeat frequency)mainly produces a vertical force.Changing mean stroke angle mainly produces a pitch moment.Changing wing angle of attack,when down-and upstrokes have equal change,mainly produces a vertical force,while when down-and upstrokes have opposite changes,mainly produces a horizontal force and a pitch moment.Changing wing rotation timing,when dorsal and ventral rotations have the same timing,mainly produces a vertical force,while when dorsal and ventral rotations have opposite timings,mainly produces a pitch moment and a horizontal force.Changing rotation duration has very small effect on forces and moments.Anti-symmetrically changing stroke amplitude(or wingbeat frequency)of the contralateral wings mainly produces a roll moment.Anti-symmetrically changing angles of attack of the contralateral wings,when down-and upstrokes have equal change,mainly produces a roll moment,while when down-and upstrokes have opposite changes,mainly produces a yaw moment.Anti-symmetrically changing wing rotation timing of the contralateral wings,when dorsal and ventral rotations have the same timing,mainly produces a roll moment and a side force,while when dorsal and ventral rotations have opposite timings,mainly produces a yaw moment.Vertical force and moments about the three axes can be separately controlled by separate kinematic variables.A very fast rotation can be achieved with moderate changes in wing kinematics.

  9. Apibacter mensalis sp. nov.: a rare member of the bumblebee gut microbiota.

    Science.gov (United States)

    Praet, Jessy; Aerts, Maarten; Brandt, Evie De; Meeus, Ivan; Smagghe, Guy; Vandamme, Peter

    2016-04-01

    Isolates LMG 28357T ( = R-53146T) and LMG 28623 were obtained from gut samples of Bombus lapidarius bumblebees caught in Ghent, Belgium. They had identical 16S rRNA gene sequences which were 95.7 % identical to that of Apibacter adventoris wkB301T, a member of the family Flavobacteriaceae. Both isolates had highly similar matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS and randomly amplified polymorphic DNA (RAPD) profiles. A draft genome sequence was obtained for strain LMG 28357T (Gold ID Gp0108260); its DNA G+C content was 30.4 %, which is within the range reported for members of the family Flavobacteriaceae (27 to 56 mol%) and which is similar to that of the type strain of A. adventoris (29.0 mol%). Whole-cell fatty acid methyl ester analysis of strain LMG 28357T revealed many branched-chain fatty acids, a typical characteristic of bacteria of the family Flavobacteriaceae and a profile that was similar to that reported for A. adventoris wkB301T. MK6 was the major respiratory quinone, again conforming to bacteria of the family Flavobacteriaceae. The isolates LMG 28357T and LMG 28623 could be distinguished from A. adventoris strains through their oxidase activity. On the basis of phylogenetic, genotypic and phenotypic data, we propose to classify both isolates as representatives of a novel species of the genus Apibacter, Apibacter mensalis sp. nov., with LMG 28357T ( = DSM 100903T = R-53146T) as the type strain. PMID:26813786

  10. Long term effects of aversive reinforcement on colour discrimination learning in free-flying bumblebees.

    Directory of Open Access Journals (Sweden)

    Miguel A Rodríguez-Gironés

    Full Text Available The results of behavioural experiments provide important information about the structure and information-processing abilities of the visual system. Nevertheless, if we want to infer from behavioural data how the visual system operates, it is important to know how different learning protocols affect performance and to devise protocols that minimise noise in the response of experimental subjects. The purpose of this work was to investigate how reinforcement schedule and individual variability affect the learning process in a colour discrimination task. Free-flying bumblebees were trained to discriminate between two perceptually similar colours. The target colour was associated with sucrose solution, and the distractor could be associated with water or quinine solution throughout the experiment, or with one substance during the first half of the experiment and the other during the second half. Both acquisition and final performance of the discrimination task (measured as proportion of correct choices were determined by the choice of reinforcer during the first half of the experiment: regardless of whether bees were trained with water or quinine during the second half of the experiment, bees trained with quinine during the first half learned the task faster and performed better during the whole experiment. Our results confirm that the choice of stimuli used during training affects the rate at which colour discrimination tasks are acquired and show that early contact with a strongly aversive stimulus can be sufficient to maintain high levels of attention during several hours. On the other hand, bees which took more time to decide on which flower to alight were more likely to make correct choices than bees which made fast decisions. This result supports the existence of a trade-off between foraging speed and accuracy, and highlights the importance of measuring choice latencies during behavioural experiments focusing on cognitive abilities.

  11. Recommendations for FITS Headers

    OpenAIRE

    Hourclé, Joseph

    2012-01-01

    We present an example of best practices for FITS Headers to improve documentation and accessibility of solar physics data distributed as FITS files. We build on existing norms and standards, including ‘Proposed Keywords for SOHO’ and the FITS World Coordinate System (WCS) conventions, and include recommendations on the use of FITS features and extensions to help make data stored and distributed in FITS better suited for both present-day usage and for long-term archiving. O...

  12. Comparison of pollination and defensive buzzes in bumblebees indicates species-specific and context-dependent vibrations

    Science.gov (United States)

    De Luca, Paul A.; Cox, Darryl A.; Vallejo-Marín, Mario

    2014-04-01

    Bees produce vibrations in many contexts, including for defense and while foraging. Buzz pollination is a unique foraging behavior in which bees vibrate the anthers of flowers to eject pollen which is then collected and used as food. The relationships between buzzing properties and pollen release are well understood, but it is less clear to what extent buzzing vibrations vary among species, even though such information is crucial to understanding the functional relationships between bees and buzz-pollinated plants. Our goals in this study were (1) to examine whether pollination buzzes differ from those produced during defense, (2) to evaluate the similarity of buzzes between different species of bumblebees ( Bombus spp.), and (3) to determine if body size affects the expression of buzzing properties. We found that relative peak amplitude, peak frequency, and duration were significantly different between species, but only relative peak amplitude differed between pollination and defensive buzzes. There were significant interactions between species and buzz type for peak frequency and duration, revealing that species differed in their patterns of expression in these buzz properties depending on the context. The only parameter affected by body size was duration, with larger bees producing shorter buzzes. Our findings suggest that although pollination and defensive buzzes differ in some properties, variability in buzz structure also exhibits a marked species-specific component. Species differences in pollination buzzes may have important implications for foraging preferences in bumblebees, especially if bees select flowers best matched to release pollen for their specific buzzing characteristics.

  13. Nectar robbing, forager efficiency and seed set: Bumblebees foraging on the self incompatible plant Linaria vulgaris (Scrophulariaceae)

    Science.gov (United States)

    Stout, Jane C.; Allen, John A.; Goulson, Dave

    2000-07-01

    In southern England, Linaria vulgaris (common yellow toadflax) suffers from high rates of nectar robbery by bumblebees. In a wild population of L. vulgaris we found that 96 % of open flowers were robbed. Five species of bumblebee were observed foraging on these flowers, although short-tongued species ( Bombus lapidarius, B. lucorum and B. terrestris) robbed nectar whilst longer-tongued ones behaved as legitimate pollinators ( B. hortorum and B. pascuorum). Nectar rewards were highly variable; on average there was less nectar in robbed than in unrobbed flowers, but this difference was not statistically significant. The proportion of flowers containing no nectar was significantly higher for robbed flowers compared with unrobbed flowers. Secondary robbers and legitimate pollinators had similar handling times on flowers and, assuming they select flowers at random to forage on, received approximately the same nectar profit per minute, largely because most flowers had been robbed. There was no significant difference in the number of seeds in pods of robbed flowers and in pods of flowers that were artificially protected against robbing. However, more of the robbed flowers set at least some seed than the unrobbed flowers, possibly as a consequence of the experimental manipulation. We suggest that nectar robbing has little effect on plant fecundity because legitimate foragers are present in the population, and that seed predation and seed abortion after fertilization may be more important factors in limiting seed production in this species.

  14. Exotic Endurance: Tourism, Fitness and the Marathon des Sables

    OpenAIRE

    Lisle, Debbie

    2016-01-01

    This paper critically examines the intersections of global tourism and fitness in the Marathon des Sables, an annual ultramarathon in the Sahara desert in which over a thousand athletes run the equivalent of five marathons in six days. It demonstrates how the globalization of health and fitness resonates with familiar Western productions of exotic cultures for the purposes of tourist consumption. Of particular interest here is how established colonial asymmetries are recast in a neoliberal co...

  15. Divergent rules for pollen and nectar foraging bumblebees--a laboratory study with artificial flowers offering diluted nectar substitute and pollen surrogate.

    Directory of Open Access Journals (Sweden)

    Sabine Konzmann

    Full Text Available Almost all bees collect nectar and pollen from flowers. Female bees collect pollen to provision their nest cells, whereas they use nectar for individual energy supply and nest cell provisioning. Bees fine-tune nectar foraging to the amount and to the concentration of nectar, but the individual bees' response to variability of amount and concentration of pollen reward has not yet been studied thoroughly in laboratory settings. We developed an experimental set-up in which bumblebees simultaneously collected sugar solution and pollen from artificial flowers; natural pollen was mixed with cellulose powder or glass powder as a pollen surrogate. Here we show that bumblebee (Bombus terrestris workers do not specialise in nectar or pollen collection, but regularly collect both rewards on the same day. When offered a fixed pollen reward and varied amounts and concentrations of sugar solution, the bumblebees fine-tuned sugar solution foraging dependent on both the volume and concentration, with strong preferences for the highest concentration and the greatest volume. In the reciprocal tests, when offered a fixed sugar reward and varied amounts and concentrations of pollen mixed with a nutrient-free pollen surrogate, the bumblebees follow more an all-or-none rule for pollen, accepting all amounts and concentrations except pure surrogate. It is discussed how the bumblebees' ability to sense sugar, and their apparent inability to sense the pollen protein content, shaped their foraging behaviour. It is argued that the rarity of nectar mimicry and the frequency of pollen mimicry in natural flowers might be interpreted in the context of divergent abilities of nectar and pollen recognition in bees.

  16. Fractal Growth of Bacterial Colonies

    Czech Academy of Sciences Publication Activity Database

    Růžička, Marek; Fridrich, Miroslav; Burkhard, M.

    London : Chapman&Hall, 1995 - (Novak, M.M.), s. 179-191 ISBN 0-412-71020-X. [Fractal Reviews in the Natural and Applied Sciences. Marseille (FI), 07.02.1995-10.02.1995] Institutional support: RVO:67985858 Keywords : fractal * bacteria l colony * growth pattern Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  17. Ant Colony Optimization for Control

    NARCIS (Netherlands)

    Van Ast, J.M.

    2010-01-01

    The very basis of this thesis is the collective behavior of ants in colonies. Ants are an excellent example of how rather simple behavior on a local level can lead to complex behavior on a global level that is beneficial for the individuals. The key in the self-organization of ants is communication

  18. Landscape mulches and termite nutritional ecology: growth and survival of incipient colonies of Coptotermes formosanus (Isoptera: Rhinotermitidae).

    Science.gov (United States)

    Sun, Jian-Zhong

    2007-04-01

    Alate swarms are one of the major visible signs of the expansion of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in an area. Successful establishment of an incipient colony is thought to mainly rely on available food resources and moisture. The large-scale use of tree-based mulches in landscapes may inadvertently contribute to local establishment and growth of C. formosanus colonies. This research investigated the nutritional ecology of incipient colonies of C. formosanus feeding on seven tree-based, weathered, and nonweathered landscape mulches: pine straw, pine bark, cedar wood, water oak, eucalyptus, cypress, and melaleuca. Incipient colonies of C. formosanus feeding on pine straw, either weathered or nonweathered, produced significantly more progeny over the course of 1-yr feeding than colonies feeding on the other mulches tested. Regardless of weathered or not, the incipient colonies feeding on pine straw, eucalyptus, bald cypress, and water oak mulches had significantly greater survival rates after 360 d (53-77%) than colonies feeding on the other mulches tested (0-13%), but colonies feeding on nonweathered water oak had significantly lower survival (8%) than those kept on weathered water oak (58%). Colony fitness values were significantly different between the weathering treatment groups and among the different types of mulches. With regard to colony growth characteristics, three distinct growth patterns were identified: a high number of progeny (>100) with high colony survival rate (>50%), a medium number of progeny (12-50) with high colony survival rate (>50%), and a small number of progeny (0-10) with low colony survival rate (<5%). These findings suggest that different types of mulch substrates could significantly impact the nutritional ecology of the founding pairs and the successful establishment of incipient colonies during the swarming season. PMID:17461078

  19. Measuring the sugar consumption of larvae in bumblebee micro-colonies: a promising new method for tracking food economics in bees

    Czech Academy of Sciences Publication Activity Database

    Řehoř, Ivan; Macháčková, L.; Bučánková, A.; Matějková, Stanislava; Černá, K.; Straka, J.

    2014-01-01

    Roč. 45, č. 1 (2014), s. 116-128. ISSN 0044-8435 R&D Projects: GA TA ČR TA01020969 Grant ostatní: GA ČR(CZ) GAP506/10/0403 Institutional support: RVO:61388963 Keywords : marking technique * lanthanide * carbohydrate * insect * ICP-OES Subject RIV: EG - Zoology Impact factor: 1.676, year: 2014

  20. Représenter les lieux et les populations dans une colonie de peuplement: un siècle de recensements sud-africains / Mapping places and people in a settler society: From discrepancy to good fit over one century of South African censuses

    Directory of Open Access Journals (Sweden)

    Frédéric Giraut

    2012-08-01

    Full Text Available Depuis plus d'un siècle, l'Afrique du Sud a connu une remarquable série de recensements. Ceux-ci enregistrent la dynamique du peuplement dans le cadre de catégories socio-spatiales changeantes et liées aux représentations et projets successifs: coloniaux, d'apartheid et post-apartheid. Les premiers recensements proposaient une hiérarchisation des lieux typiques d'une colonie de peuplement. Le mouvement d'urbanisation, impliquant les populations non européennes, s'est traduit par l'évolution de la représentation officielle avec une reconnaissance progressive de localités autochtones. Sur un siècle, la géographie officielle des lieux de peuplement sud-africains est passée d'une perspective de société de pionniers à une perspective postcoloniale reconnaissant l'ensemble des communautés à travers leurs espaces.The dynamics of population and urbanization in South Africa have been recorded by a remarkable set of censuses during the 20th century. These censuses indicate a changing hierarchy of places that is typical of a settler society and of its representations of space and society. Over one century, the official census places and the pattern of population distribution have shifted from a selective colonial view of human settlements to an inclusive postcolonial society view closer to the distribution of the whole population.

  1. Recruitment Strategies and Colony Size in Ants

    OpenAIRE

    Planqué, Robert; van den Berg, Jan Bouwe; Franks, Nigel R

    2010-01-01

    Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explana...

  2. Ant colony optimization in continuous problem

    Institute of Scientific and Technical Information of China (English)

    YU Ling; LIU Kang; LI Kaishi

    2007-01-01

    Based on the analysis of the basic ant colony optimization and optimum problem in a continuous space,an ant colony optimization (ACO) for continuous problem is constructed and discussed. The algorithm is efficient and beneficial to the study of the ant colony optimization in a continuous space.

  3. Family Activities for Fitness

    Science.gov (United States)

    Grosse, Susan J.

    2009-01-01

    This article discusses how families can increase family togetherness and improve physical fitness. The author provides easy ways to implement family friendly activities for improving and maintaining physical health. These activities include: walking, backyard games, and fitness challenges.

  4. Outdoor fitness routine

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000891.htm Outdoor fitness routine To use the sharing features on this ... you and is right for your level of fitness. Here are some ideas: Warm up first. Get ...

  5. Fitness Shoes and Clothes

    Science.gov (United States)

    ... My Go4Life Get Free Stuff Be a Partner Fitness Shoes and Clothes Choosing the right clothing and ... be a great motivator! Download the Tip Sheet Fitness Shoes and Clothes (PDF, 436.87 KB) You ...

  6. Does CEO fitness matter?

    OpenAIRE

    Limbach, Peter; Sonnenburg, Florian

    2015-01-01

    This study provides evidence suggesting that CEOs' physical fitness has a positive impact on firm value, consistent with the beneficial effects of fitness on, e.g., cognitive functions, stress coping and job performance. For each of the years 2001 to 2011, we define S&P 1500 CEOs as fit if they finish a marathon. CEO fitness is also associated with higher firm profitability and higher M&A announcement returns. Our identification strategy includes CEO-firm fixed effects, instrumental variables...

  7. Computer code FIT

    International Nuclear Information System (INIS)

    This is a description of the computer code FIT, written in FORTRAN-77 for a PDP 11/34. FIT is an interactive program to decude position, width and intensity of lines of X-ray spectra (max. length of 4K channels). The lines (max. 30 lines per fit) may have Gauss- or Voigt-profile, as well as exponential tails. Spectrum and fit can be displayed on a Tektronix terminal. (orig.)

  8. Reaching Your Fitness Goals

    Science.gov (United States)

    Everyday Fitness Ideas from the National Institute on Aging at NIH www.nia.nih.gov/Go4Life Reaching Your Fitness Goals You’ll begin to see results in ... longer, and more easily. As you increase your fitness level, you also might find that you need ...

  9. One Kilogram Interstellar Colony Mission

    Science.gov (United States)

    Mole, A.

    Small interstellar colony probes based on nanotechnology will become possible long before giant multi-generation ships become affordable. A beam generator and magnetic sail can accelerate a one kg probe to .1 c, braking via the interstellar field can decelerate it, and the field in a distant solar system can allow it to maneuver to an extrasolar planet. A heat shield is used for landing and nanobots emerge to build ever-larger robots and construct colony infrastructure. Humans can then be generated from genomes stored as data in computer memory. Technology is evolving towards these capabilities and should reach the required level in fifty years. The plan appears to be affordable, with the principal cost being the beam generator, estimated at $17 billion.

  10. Nest- and colony-mate recognition in polydomous colonies of meat ants ( Iridomyrmex purpureus)

    Science.gov (United States)

    van Wilgenburg, E.; Ryan, D.; Morrison, P.; Marriott, P. J.; Elgar, M. A.

    2006-07-01

    Workers of polydomous colonies of social insects must recognize not only colony-mates residing in the same nest but also those living in other nests. We investigated the impact of a decentralized colony structure on colony- and nestmate recognition in the polydomous Australian meat ant ( Iridomyrmex purpureus). Field experiments showed that ants of colonies with many nests were less aggressive toward alien conspecifics than those of colonies with few nests. In addition, while meat ants were almost never aggressive toward nestmates, they were frequently aggressive when confronted with an individual from a different nest within the same colony. Our chemical analysis of the cuticular hydrocarbons of workers using a novel comprehensive two-dimensional gas chromatography technique that increases the number of quantifiable compounds revealed both colony- and nest-specific patterns. Combined, these data indicate an incomplete transfer of colony odor between the nests of polydomous meat ant colonies.

  11. Colonial adventures in tropical agriculture

    OpenAIRE

    Buelens, Frans; Frankema, Ewout

    2015-01-01

    How profitable were foreign investments in plantation agriculture in the Netherlands Indies during the late colonial era? We use a new dataset of monthly quoted stock prices and dividends of international companies at the Brussels stock exchange to estimate the returns to investment in tropical agriculture (1919–1938). We adopt the Dimson–March–Staunton method to compute real geometric annual average rates of return and assess our estimates in an international comparative perspective. We find...

  12. Changing Views on Colonial Heritage

    OpenAIRE

    Roosmalen, P.K.M. van

    2003-01-01

    Within the context of a rational study and in order to arrive at a balanced appreciation of nineteenth and twentieth century heritage worldwide, architecture and town planning realized under colonial rule requires special attention. This paper describes the strengths and need for a revised vision of this particular heritage and the considerations and criteria that should be taken into account for evaluation of the objects. The Dutch East Indies are used as a stepping stone.

  13. Honeybee immunity and colony losses

    Directory of Open Access Journals (Sweden)

    F. Nazzi

    2014-10-01

    Full Text Available The decline of honeybee colonies and their eventual collapse is a widespread phenomenon in the Northern hemisphere of the globe, which severely limits the beekeeping industry. This dramatic event is associated with an enhanced impact of parasites and pathogens on honeybees, which is indicative of reduced immunocompetence. The parasitic mite Varroa destructor and the vectored viral pathogens appear to play a key-role in the induction of this complex syndrome. In particular, the Deformed Wing Virus (DWV is widespread and is now considered, along with Varroa, one of the major causes of bee colony losses. Several lines of evidence indicate that this mite/DWV association severely affects the immune system of honeybees and makes them more sensitive to the action of other stress factors. The molecular mechanisms underpinning these complex interactions are currently being investigated and the emerging information has allowed the development of a new functional model, describing how different stress factors may synergistically concur in the induction of bee immune alteration and health decline. This provides a new logical framework in which to interpret the proposed multifactorial origin of bee colony losses and sets the stage for a more comprehensive and integrated analysis of the effect that multiple stress agents may have on honeybees.

  14. Exploration adjustment by ant colonies.

    Science.gov (United States)

    Doran, Carolina; Stumpe, Martin C; Sendova-Franks, Ana; Franks, Nigel R

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  15. Deadly competition between sibling bacterial colonies

    Science.gov (United States)

    Be'Er, Avraham

    2011-03-01

    As a result of stress due to nutrient limitation or antibiotics, competing individual bacteria within a single colony may lyse sibling cells to release nutrients (cannibalism) or DNA (fratricide). However, we have recently shown that competition is not limited to individuals, but can occur at the colony level [A. Be'er et al., PNAS 106, 428 (2009); A. Be'er et al., PNAS 107, 6258 (2010).] In response to the presence of an encroaching sibling colony, Paenibacillus dendritiformis bacteria secrete a lethal protein, lysing cells at the interface between the colonies. Analysis of the proteins secreted by these competing sibling colonies, combined with a mathematical model, shows how colonies maintain their growth by self-regulating the secretion of two proteins: subtilisin (a well-known growth promoter), and Slf (a previously unknown protein, which is lethal). The results also explain why a single colony is not inhibited by its own secretions.

  16. Text clustering based on fusion of ant colony and genetic algorithms

    Institute of Scientific and Technical Information of China (English)

    Yun ZHANG; Boqin FENG; Shouqiang MA; Lianmeng LIU

    2009-01-01

    Focusing on the problem that the ant colony algorithm gets into stagnation easily and cannot fully search in solution space,a text clustering approach based on the fusion of the ant colony and genetic algorithms is proposed.The four parameters that influence the performance of the ant colony algorithm are encoded as chromosomes,thereby the fitness function,selection,crossover and mutation operator are designed to find the combination of optimal parameters through a number of iteration,and then it is applied to text clustering.The simulation.results show that compared with the classical k-means clustering and the basic ant colony clustering algorithm,the proposed algorithm has better performance and the value of F-Measure is enhanced by 5.69%,48.60% and 69.60%,respectively,in 3 test datasets.Therefore,it is more suitable for processing a larger dataset.

  17. The queen is not a pacemaker in the small-colony wasps Polistes instabilis and P. dominulus

    DEFF Research Database (Denmark)

    Jha, Shalene; Casey-Ford, Rowan G.; Pedersen, Jes Søe;

    2006-01-01

    suggest that two species of paper wasps do not fit this pattern. Polistes wasps are traditionally classified as primitively eusocial wasps, showing characteristics of simple insect societies, such as small colony sizes, lack of queen-worker dimorphism, and queen control of both reproduction and worker...... which the queen was removed did not differ significantly from activity levels in colonies with queens. Polistes instabilis and P. dominulus colonies showed characteristics of primitively eusocial insect societies, but also showed worker initiation of colony activity, suggesting that these two species......How work is organized varies in social insect colonies. Some investigators have argued that the queen plays an active role in regulating worker activity in species with small, simple colonies, but that work is self-organized in species with large, complex colonies. Here, we present data that...

  18. On the evolutionary ecology of host-parasite interactions: addressing the question with regard to bumblebees and their parasites

    Science.gov (United States)

    Schmid-Hempel, Paul

    2001-05-01

    Over the last decade, there has been a major shift in the study of adaptive patterns and processes towards including the role of host-parasite interactions, informed by concepts from evolutionary ecology. As a consequence, a number of major questions have emerged. For example, how genetics affects host-parasite interactions, whether parasitism selects for offspring diversification, whether parasite virulence is an adaptive trait, and what constrains the use of the host's immune defences. Using bumblebees, Bombus spp, and their parasites as a model system, answers to some of these questions have been found, while at the same time the complexity of the interaction has led expectations away from simple theoretical models. In addition, the results have also led to the unexpected discovery of novel phenomena concerning, for instance, female mating strategies.

  19. Symmetry is in the eye of the `beeholder': innate preference for bilateral symmetry in flower-naïve bumblebees

    Science.gov (United States)

    Rodríguez, Ivana; Gumbert, Andreas; Hempel de Ibarra, Natalie; Kunze, Jan; Giurfa, Martin

    Bilateral symmetry has been considered as an indicator of phenotypic and genotypic quality supporting innate preferences for highly symmetric partners. Insect pollinators preferentially visit flowers of a particular symmetry type, thus leading to the suggestion that they have innate preferences for symmetrical flowers or flower models. Here we show that flower-naïve bumblebees (Bombus terrestris), with no experience of symmetric or asymmetric patterns and whose visual experience was accurately controlled, have innate preferences for bilateral symmetry. The presence of color cues did not influence the bees' original preference. Our results thus show that bilateral symmetry is innately preferred in the context of food search, a fact that supports the selection of symmetry in flower displays. Furthermore, such innate preferences indicate that the nervous system of naïve animals may be primed to respond to relevant sensory cues in the environment.

  20. Robustness of Ant Colony Optimization to Noise.

    Science.gov (United States)

    Friedrich, Tobias; Kötzing, Timo; Krejca, Martin S; Sutton, Andrew M

    2016-01-01

    Recently, ant colony optimization (ACO) algorithms have proven to be efficient in uncertain environments, such as noisy or dynamically changing fitness functions. Most of these analyses have focused on combinatorial problems such as path finding. We rigorously analyze an ACO algorithm optimizing linear pseudo-Boolean functions under additive posterior noise. We study noise distributions whose tails decay exponentially fast, including the classical case of additive Gaussian noise. Without noise, the classical [Formula: see text] EA outperforms any ACO algorithm, with smaller [Formula: see text] being better; however, in the case of large noise, the [Formula: see text] EA fails, even for high values of [Formula: see text] (which are known to help against small noise). In this article, we show that ACO is able to deal with arbitrarily large noise in a graceful manner; that is, as long as the evaporation factor [Formula: see text] is small enough, dependent on the variance [Formula: see text] of the noise and the dimension n of the search space, optimization will be successful. We also briefly consider the case of prior noise and prove that ACO can also efficiently optimize linear functions under this noise model. PMID:26928850

  1. Visual motion-sensitive neurons in the bumblebee brain convey information about landmarks during a navigational task

    Directory of Open Access Journals (Sweden)

    Marcel eMertes

    2014-09-01

    Full Text Available Bees use visual memories to find the spatial location of previously learnt food sites. Characteristic learning flights help acquiring these memories at newly discovered foraging locations where landmarks - salient objects in the vicinity of the goal location - can play an important role in guiding the animal’s homing behavior. Although behavioral experiments have shown that bees can use a variety of visual cues to distinguish objects as landmarks, the question of how landmark features are encoded by the visual system is still open. Recently, it could be shown that motion cues are sufficient to allow bees localizing their goal using landmarks that can hardly be discriminated from the background texture. Here, we tested the hypothesis that motion sensitive neurons in the bee’s visual pathway provide information about such landmarks during a learning flight and might, thus, play a role for goal localization. We tracked learning flights of free-flying bumblebees (Bombus terrestris in an arena with distinct visual landmarks, reconstructed the visual input during these flights, and replayed ego-perspective movies to tethered bumblebees while recording the activity of direction-selective wide-field neurons in their optic lobe. By comparing neuronal responses during a typical learning flight and targeted modifications of landmark properties in this movie we demonstrate that these objects are indeed represented in the bee’s visual motion pathway. We find that object-induced responses vary little with object texture, which is in agreement with behavioral evidence. These neurons thus convey information about landmark properties that are useful for view-based homing.

  2. Improvised Scout Bee Movements in Artificial Bee Colony

    OpenAIRE

    Tarun Kumar Sharma; Millie Pant

    2014-01-01

    In the basic Artificial Bee Colony (ABC) algorithm, if the fitness value associated with a food source is not improved for a certain number of specified trials then the corresponding bee becomes a scout to which a random value is assigned for finding the new food source. Basically, it is a mechanism of pulling out the candidate solution which may be entrapped in some local optimizer due to which its value is not improving. In the present study, we propose two new mechanisms for the movements ...

  3. Leak test fitting

    Science.gov (United States)

    Pickett, P.T.

    A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

  4. Sensitive determination of mixtures of neonicotinoid and fungicide residues in pollen and single bumblebees using a scaled down QuEChERS method for exposure assessment.

    Science.gov (United States)

    David, Arthur; Botías, Cristina; Abdul-Sada, Alaa; Goulson, Dave; Hill, Elizabeth M

    2015-10-01

    To accurately estimate exposure of bees to pesticides, analytical methods are needed to enable quantification of nanogram/gram (ng/g) levels of contaminants in small samples of pollen or the individual insects. A modified QuEChERS extraction method coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis was tested to quantify residues of 19 commonly used neonicotinoids and fungicides and the synergist, piperonyl butoxide, in 100 mg samples of pollen and in samples of individual bumblebees (Bombus terrestris). Final recoveries ranged from 71 to 102 % for most compounds with a repeatability of below 20 % for both pollen and bumblebee extracts spiked at 5 and 40 ng/g. The method enables the detection of all compounds at sub-ng/g levels in both matrices and the method detection limits (MDL) ranged from 0.01 to 0.84 ng/g in pollen and 0.01 to 0.96 ng/g in individual bumblebees. Using this method, mixtures of neonicotinoids (thiamethoxam, clothianidin, imidacloprid and thiacloprid) and fungicides (carbendazim, spiroxamine, boscalid, tebuconazole, prochloraz, metconazole, fluoxastrobin, pyraclostrobin and trifloxystrobin) were detected in pollens of field bean, strawberry and raspberry at concentrations ranging from MDL, and in some bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations between 0.80 to 30 ng/g. This new method allows the analysis of mixtures of neonicotinoids and fungicides at trace levels in small quantities of pollen and individual bumblebees and thus will facilitate exposure assessment studies. PMID:26329280

  5. Varroa destructor Macula-like virus, Lake Sinai virus and other new RNA viruses in wild bumblebee hosts (Bombus pascuorum, Bombus lapidarius and Bombus pratorum).

    Science.gov (United States)

    Parmentier, Laurian; Smagghe, Guy; de Graaf, Dirk C; Meeus, Ivan

    2016-02-01

    Pollinators such as bumblebees (Bombus spp.) are in decline worldwide which poses a threat not only for ecosystem biodiversity but also to human crop production services. One main cause of pollinator decline may be the infection and transmission of diseases including RNA viruses. Recently, new viruses have been discovered in honeybees, but information on the presence of these in wild bumblebees is largely not available. In this study, we investigated the prevalence of new RNA viruses in Bombus species, and can report for the first time Varroa destructor Macula-like virus (VdMLV) and Lake Sinai virus (LSV) infection in multiple wild bumblebee hosts of Bombus pascuorum, Bombus lapidarius and Bombus pratorum. We sampled in 4 locations in Flanders, Belgium. Besides, we confirmed Slow bee paralysis virus (SBPV) in wild bumblebees, but no positive samples were obtained for Big Sioux river virus (BSRV). Secondly, we screened for the influence of apiaries on the prevalence of these viruses. Our results indicated a location effect for the prevalence of VdMLV in Bombus species, with a higher prevalence in the proximity of honeybee apiaries mainly observed in one location. For LSV, the prevalence was not different in the proximity or at a 1.5 km-distance of apiaries, but we reported a different isolate with similarities to LSV-2 and "LSV-clade A" as described by Ravoet et al. (2015), which was detected both in Apis mellifera and Bombus species. In general, our results indicate the existence of a disease pool of new viruses that seems to be associated to a broad range of Apoidae hosts, including multiple Bombus species. PMID:26706994

  6. An Authomated approach for Bacterial Colony Counter

    Directory of Open Access Journals (Sweden)

    Shruti Nagpal

    2012-03-01

    Full Text Available Counting of bacterial colonies is complex task for microbiologist. To a large extent, accurate colony counting depends on the ability to see colonies distinctly, whether viewed by the naked eye or by an automated instrument. An increased area of focus in Microbiology is the automation of counting methods.. Further in an Industry thousands of such samples are formed per day and colonies on each sample are counted manually, then this becomes a time consuming hectic and error prone job.We proposed a method to count these colonies to save time with accurate results and fast delivery to customers. This proposed research work will count the colonies after 6 to 8 hours priori, saving a lot more time and this work will more efficient because market range for this is about 10,000 only as compare to prior systems.

  7. Fitness costs of worker specialization for ant societies.

    Science.gov (United States)

    Jongepier, Evelien; Foitzik, Susanne

    2016-01-13

    Division of labour is of fundamental importance for the success of societies, yet little is known about how individual specialization affects the fitness of the group as a whole. While specialized workers may be more efficient in the tasks they perform than generalists, they may also lack the flexibility to respond to rapid shifts in task needs. Such rigidity could impose fitness costs when societies face dynamic and unpredictable events, such as an attack by socially parasitic slavemakers. Here, we experimentally assess the colony-level fitness consequences of behavioural specialization in Temnothorax longispinosus ants that are attacked by the slavemaker ant T. americanus. We manipulated the social organization of 102 T. longispinosus colonies, based on the behavioural responses of all 3842 workers. We find that strict specialization is disadvantageous for a colony's annual reproduction and growth during slave raids. These fitness costs may favour generalist strategies in dynamic environments, as we also demonstrate that societies exposed to slavemakers in the field show a lower degree of specialization than those originating from slavemaker-free populations. Our findings provide an explanation for the ubiquity of generalists and highlight their importance for the flexibility and functional robustness of entire societies. PMID:26763706

  8. Alternative Modernities for Colonial Korea

    Directory of Open Access Journals (Sweden)

    Steven Lee

    2016-06-01

    Full Text Available Sunyoung Park. The Proletarian Wave: Literature and Leftist Culture in Colonial Korea, 1910–1945. Cambridge, MA: Harvard University Asia Center, 2015. 348 pp. $50 (cloth. Vladimir Tikhonov. Modern Korea and Its Others: Perceptions of the Neighbouring Countries and Korean Modernity. London: Routledge, 2016. 218 pp. $160 (cloth. It has become a global scholarly undertaking: how to rethink modernity so as to decouple it from Westernization (Chakrabarty 2000. Strategies have included foregrounding the plurality of history to disrupt linear progress; positing non-Western centers of modernity in, say, Moscow or Shanghai; and tracing anticolonial circuits connecting Asia to Africa to Latin America. The two recent books under review here add colonial-era Korea to such far-reaching discussions by situating the country across national boundaries. Interestingly, one connecting thread here is the alternative world system provided by the interwar, Soviet-oriented Left. The result is an unsettling of binaries that subsequently became entrenched during the Cold War: for example, north-south, socialist-nationalist, and, for literature, realist-modernist. But more broadly, pervading both books is the sense that history could have turned out differently—that revisiting northeast Asia’s porous borders in the early twentieth century reveals the Korean peninsula’s lost, internationalist potential...

  9. Growth and form of melanoma cell colonies

    OpenAIRE

    Baraldi, Massimiliano Maria; Alemi, Alexander A.; Sethna, James P.; Caracciolo, Sergio; La Porta, Caterina A. M.; Zapperi, Stefano

    2013-01-01

    We study the statistical properties of melanoma cell colonies grown in vitro by analyzing the results of crystal violet assays at different concentrations of initial plated cells and for di?erent growth times. The distribution of colony sizes is described well by a continuous time branching process. To characterize the shape fluctuations of the colonies, we compute the distribution of eccentricities. The experimental results are compared with numerical results for models of random division of...

  10. CULTURAL DIVERSITY AND ORIENTALISTSIN THE COLONIAL INDIA

    OpenAIRE

    Rohini

    2014-01-01

    This paper discusses to what extent colonial India was responsive to cultural diversity? It shows the orientalist policies of British rulers to find out how much it was favorable to the various ways of life prevailing in India during colonial times? In the colonial period we find out, how the colonizers in India insisted on their distinctness instead of accepting the path of assimilation. The Orientalist administrators and scholars presented India as having a long living civil...

  11. Towards a multilevel ant colony optimization

    OpenAIRE

    Lian, Thomas Andreé; Llave, Marilex Rea

    2014-01-01

    Ant colony optimization is a metaheuristic approach for solving combinatorial optimization problems which belongs to swarm intelligence techniques. Ant colony optimization algorithms are one of the most successful strands of swarm intelligence which has already shown very good performance in many combinatorial problems and for some real applications. This thesis introduces a new multilevel approach for ant colony optimization to solve the NP-hard problems shortest path and traveling salesman....

  12. GRID SCHEDULING USING ENHANCED ANT COLONY ALGORITHM

    OpenAIRE

    Mr. P.Mathiyalagan; U.R. Dhepthie; S.N. Sivanandam

    2010-01-01

    Grid computing is a high performance computing used to solve larger scale computational demands. Task scheduling is a major issue in grid computing systems. Scheduling of tasks is the NP hard problem. The heuristic approach provides optimal solution for NP hard problems .The ant colony algorithm provides optimal solution. The existing ant colony algorithm takes more time to schedule the tasks. In this paper ant colony algorithm improved by enhancing pheromone updating rule such that it schedu...

  13. Fitness Test and Tips

    Institute of Scientific and Technical Information of China (English)

    Karen; Clark

    2005-01-01

    Summer is a time to exercise and keep fit.Ask yourself these quick questions and check your score below.How fit are you? 1.What is your pulse[脉搏]?Find your pulse in your wrist[手腕], count the number of beats[跳动] in one minute,Now

  14. Fun Fitness Runs.

    Science.gov (United States)

    Scantling, Ed; Strand, Brad

    1997-01-01

    Fitness runs are planned activities that make running more interesting. The paper outlines five types of fitness runs, all of which can be modified to conform to different facilities, age groups, or available time. The activities have students playing detective, playing cards, deciphering words, learning about calories, and playing wolf. (SM)

  15. Physical Fitness and Counseling.

    Science.gov (United States)

    Helmkamp, Jill M.

    Human beings are a delicate balance of mind, body, and spirit, so an imbalance in one domain affects all others. The purpose of this paper is to examine the effects that physical fitness may have on such human characteristics as personality and behavior. A review of the literature reveals that physical fitness is related to, and can affect,…

  16. Energy Aware Reliable Routing Protocol (EARRP) for Mobile AdHoc Networks Using Bee Foraging Behavior and Ant Colony Optimization

    OpenAIRE

    K. G. Santhiya; Arumugam, N.

    2012-01-01

    Energy aware reliable routing in mobile ad hoc networks is an astonishing task and in this paper we propose to design, develop such protocol which will be a good solution. For developing such protocol EARRP, two swarm intelligence techniques are involved namely ant colony optimization and bee colony foraging behavior. For optimization, we proposed adaptive solutions in order to estimate MAC overhead, link eminence and residual energy. After estimating the above said metrics, the fitness funct...

  17. GRID SCHEDULING USING ENHANCED ANT COLONY ALGORITHM

    Directory of Open Access Journals (Sweden)

    P. Mathiyalagan

    2010-10-01

    Full Text Available Grid computing is a high performance computing used to solve larger scale computational demands. Task scheduling is a major issue in grid computing systems. Scheduling of tasks is the NP hard problem. The heuristic approach provides optimal solution for NP hard problems .The ant colony algorithm provides optimal solution. The existing ant colony algorithm takes more time to schedule the tasks. In this paper ant colony algorithm improved by enhancing pheromone updating rule such that it schedules the tasks efficiently and better resource utilization. The simulation results prove that proposed method reduces the execution time of tasks compared to existing ant colony algorithm.

  18. Ant Colony Optimization Algorithm for Continuous Domains Based on Position Distribution Model of Ant Colony Foraging

    OpenAIRE

    Liqiang Liu; Yuntao Dai; Jinyu Gao

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules...

  19. Recruitment strategies and colony size in ants.

    Directory of Open Access Journals (Sweden)

    Robert Planqué

    Full Text Available Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explanations for this correlation have focused on the ants' ecology, such as food resource distribution. However, many species have colonies with a single queen and workforces that grow over several orders of magnitude, and little is known about how a colony's organization, including recruitment methods, may change during its growth. After all, recruitment involves interactions between ants, and hence the size of the colony itself may influence which recruitment method is used--even if the ants' behavioural repertoire remains unchanged. Here we show using mathematical models that the observed correlation can also be explained by recognizing that failure rates in recruitment depend differently on colony size in various recruitment strategies. Our models focus on the build up of recruiter numbers inside colonies and are not based on optimality arguments, such as maximizing food yield. We predict that ant colonies of a certain size should use only one recruitment method (and always the same one rather than a mix of two or more. These results highlight the importance of the organization of recruitment and how it is affected by colony size. Hence these results should also expand our understanding of ant ecology.

  20. Seabird Colonies in Western Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.; Falk, K.;

    eider, Brünnich's guillemot and Arctic tern, while at least great cormorant and great black-backed gull have shown range expansions and probably also population increases in recent years. The most important areas to breeding colonial seabirds are indicated on Fig. 40. Fig. 41 shows coastlines where...... Greenland populations in an international context are the populations of northern fulmar, great cormorant, common eider, Iceland gull, kittiwake, arctic tern, Brünnich's guillemot, black guillemot and little auk. Furthermore, populations of great cormorant and great black-backed gull are probably isolated...... from other North Atlantic populations. The Iceland gull population is referred to an endemic Greenland subspecies. The population of little auks in Avanersuaq probably makes up more than 99 % of the Baffin Bay population and perhaps 80 % of the global population (Nettleship & Evans 1985). Of particular...

  1. [Notes about other epidemics in Colonial Chile].

    Science.gov (United States)

    Laval, Enrique

    2015-10-01

    In chronicles or in the historiography of the Colony in Chile there are few references about epidemics different to smallpox; like typhus, typhoid fever, dysentery, etc. Almost all, fast spreading in the country and some with high lethality, which led to overflowing the capacity of hospitals in the Chilean colonial period. PMID:26633117

  2. Outdoor fitness routine

    Science.gov (United States)

    ... your level of fitness. Here are some ideas: Warm up first. Get your blood flowing by walking for ... prevent some injuries. You should continue with your warm up until your body feels warm and you are ...

  3. Exercise and Physical Fitness

    Science.gov (United States)

    ... Increase your chances of living longer Fitting regular exercise into your daily schedule may seem difficult at ... fine. The key is to find the right exercise for you. It should be fun and should ...

  4. The universal Higgs fit

    OpenAIRE

    Pier Paolo Giardino; Kristjan Kannike(Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, 56126 Pisa, Italy); Isabella Masina(Dipartimento di Fisica e Scienze della Terra dell’Università di Ferrara and INFN, Italy); Martti Raidal; Alessandro Strumia(Dipartimento di Fisica, Università di Pisa and INFN, Italy)

    2014-01-01

    We perform a state-of-the-art global fit to all Higgs data. We synthesise them into a ‘universal’ form, which allows to easily test any desired model. We apply the proposed methodology to extract from data the Higgs branching ratios, production cross sections, couplings and to analyse composite Higgs models, models with extra Higgs doublets, supersymmetry, extra particles in the loops, anomalous top couplings, and invisible Higgs decays into Dark Matter. Best fit regions lie around the Standa...

  5. Formation and dissolution of bacterial colonies

    Science.gov (United States)

    Weber, Christoph A.; Lin, Yen Ting; Biais, Nicolas; Zaburdaev, Vasily

    2015-09-01

    Many organisms form colonies for a transient period of time to withstand environmental pressure. Bacterial biofilms are a prototypical example of such behavior. Despite significant interest across disciplines, physical mechanisms governing the formation and dissolution of bacterial colonies are still poorly understood. Starting from a kinetic description of motile and interacting cells we derive a hydrodynamic equation for their density on a surface, where most of the kinetic coefficients are estimated from experimental data for N. gonorrhoeae bacteria. We use it to describe the formation of multiple colonies with sizes consistent with experimental observations. Finally, we show how the changes in the cell-to-cell interactions lead to the dissolution of the bacterial colonies. The successful application of kinetic theory to a complex far from equilibrium system such as formation and dissolution of living bacterial colonies potentially paves the way for the physical quantification of the initial stages of biofilm formation.

  6. Hydrodynamics of bacterial colonies: A model

    Science.gov (United States)

    Lega, J.; Passot, T.

    2003-03-01

    We propose a hydrodynamic model for the evolution of bacterial colonies growing on soft agar plates. This model consists of reaction-diffusion equations for the concentrations of nutrients, water, and bacteria, coupled to a single hydrodynamic equation for the velocity field of the bacteria-water mixture. It captures the dynamics inside the colony as well as on its boundary and allows us to identify a mechanism for collective motion towards fresh nutrients, which, in its modeling aspects, is similar to classical chemotaxis. As shown in numerical simulations, our model reproduces both usual colony shapes and typical hydrodynamic motions, such as the whirls and jets recently observed in wet colonies of Bacillus subtilis. The approach presented here could be extended to different experimental situations and provides a general framework for the use of advection-reaction-diffusion equations in modeling bacterial colonies.

  7. Predictive markers of honey bee colony collapse.

    Directory of Open Access Journals (Sweden)

    Benjamin Dainat

    Full Text Available Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies.

  8. Extensive fitness and human cooperation

    OpenAIRE

    van Hateren, J.H.

    2015-01-01

    Evolution depends on the fitness of organisms, the expected rate of reproducing. Directly getting offspring is the most basic form of fitness, but fitness can also be increased indirectly by helping genetically related individuals (such as kin) to increase their fitness. The combined effect is known as inclusive fitness. Here it is argued that a further elaboration of fitness has evolved, particularly in humans. It is called extensive fitness and it incorporates producing organisms that are m...

  9. The universal Higgs fit

    DEFF Research Database (Denmark)

    Giardino, P. P.; Kannike, K.; Masina, I.;

    2014-01-01

    We perform a state-of-the-art global fit to all Higgs data. We synthesise them into a 'universal' form, which allows to easily test any desired model. We apply the proposed methodology to extract from data the Higgs branching ratios, production cross sections, couplings and to analyse composite H...... as an alternative to the Higgs, and disfavour fits with negative Yukawa couplings. We derive for the first time the SM Higgs boson mass from the measured rates, rather than from the peak positions, obtaining M-h = 124.4 +/- 1.6 GeV.......We perform a state-of-the-art global fit to all Higgs data. We synthesise them into a 'universal' form, which allows to easily test any desired model. We apply the proposed methodology to extract from data the Higgs branching ratios, production cross sections, couplings and to analyse composite...... Higgs models, models with extra Higgs doublets, supersymmetry, extra particles in the loops, anomalous top couplings, and invisible Higgs decays into Dark Matter. Best fit regions lie around the Standard Model predictions and are well approximated by our 'universal' fit. Latest data exclude the dilaton...

  10. Optimization of inclusive fitness.

    Science.gov (United States)

    Grafen, Alan

    2006-02-01

    The first fully explicit argument is given that broadly supports a widespread belief among whole-organism biologists that natural selection tends to lead to organisms acting as if maximizing their inclusive fitness. The use of optimization programs permits a clear statement of what this belief should be understood to mean, in contradistinction to the common mathematical presumption that it should be formalized as some kind of Lyapunov or even potential function. The argument reveals new details and uncovers latent assumptions. A very general genetic architecture is allowed, and there is arbitrary uncertainty. However, frequency dependence of fitnesses is not permitted. The logic of inclusive fitness immediately draws together various kinds of intra-genomic conflict, and the concept of 'p-family' is introduced. Inclusive fitness is thus incorporated into the formal Darwinism project, which aims to link the mathematics of motion (difference and differential equations) used to describe gene frequency trajectories with the mathematics of optimization used to describe purpose and design. Important questions remain to be answered in the fundamental theory of inclusive fitness. PMID:16046225

  11. Archaeological Excursion into Proximal Colony

    Directory of Open Access Journals (Sweden)

    Aleksandar Palavestra

    2016-02-01

    Full Text Available Austro-Hungarian rule in Bosnia-Herzegovina by the end of the 19th century, presided by Benjamin Kallay, the Empire’s Minister of Finance and governor of Bosnia and Herzegovina, strived to gain wider international justification for its years’ long project of “civilizing” Bosnia and Herzegovina, or particular “historizing” of this proximal colony. In the summer of 1894 the Austro-Hungarian government in Bosnia and Herzegovina organized the Congress of Archaeologists and Anthropologists in the Landesmuseum in Sarajevo. The aim of the Congress was to inform archaeologists and anthropologists about the results of archaeological investigations in the country, and to seek their advice in directing further work. The wider ideological, political, as well as theoretical context of this congress, however, was much more complex and layered, with the aim to present the constructed image of Bosnia and Herzegovina as a country of tamed and civilized European Orient of rich past and luxurious folklore. The participants of the Congress discussed the archaeological and anthropological data presented to them by the hosts, including the specially organized excavations at Butmir and Glasinac. It is interesting to analyze, from the point of view of the history of archaeological ideas, the endeavours of the participants to adapt the archaeological finds before them to the wishes of the hosts, and, on the other hand, to their favoured archaeological paradigms dominant at the time.

  12. COLONIALISM, HAN & ECO-THEOLOGY

    Directory of Open Access Journals (Sweden)

    Grace Ji-Sun Kim

    2013-06-01

    Full Text Available Today, nations exhibit imperial behaviour but not like the ancient agriculture driven landed empires or the 18-19th century mercantile empires. The land and trade divisions are not as clearly segregated as in the earlier ones, but Imperial nations do exist and do control other nations. Imperialism and colonialism has devastating effects on our world. It has nurtured self-worth through the accumulation of worldly goods for the purposes of serving their own interests and exploiting others for the sole purpose of self-gain. This is devastating not only to human beings but to the whole ecology of the planet. Consumerism drives trade, but consumer buying is now like an unchained beast with tooth and claw causing han for the exploited as well as the resources of the planet. Eco-theologians and feminist theologians examine the devastating effects to help ensure that we are seriously determined to preserve the planet. We will examine ways of rethinking and reimagining our errors and how we can work towards the right direction for a safer, sustainable planet. doi: 10.7833/111-1-15

  13. Colony Foundation in an Oceanic Seabird

    Science.gov (United States)

    Munilla, Ignacio; Genovart, Meritxell; Paiva, Vitor H.; Velando, Alberto

    2016-01-01

    Seabirds are colonial vertebrates that despite their great potential for long-range dispersal and colonization are reluctant to establish in novel locations, often recruiting close to their natal colony. The foundation of colonies is therefore a rare event in most seabird species and little is known about the colonization process in this group. The Cory’s shearwater (Calonectris diomedea) is a pelagic seabird that has recently established three new colonies in Galicia (NE Atlantic) thus expanding its distribution range 500 km northwards. This study aimed to describe the establishment and early progress of the new Galician populations and to determine the genetic and morphometric characteristics of the individuals participating in these foundation events. Using 10 microsatellite loci, we tested the predictions supported by different seabird colonization models. Possibly three groups of non-breeders, adding up to around 200 birds, started visiting the Galician colonies in the mid 2000’s and some of them eventually laid eggs and reproduced, thus establishing new breeding colonies. The Galician populations showed a high genetic diversity and a frequency of private alleles similar to or even higher than some of the large historical populations. Most individuals were assigned to several Atlantic populations and a few (if any) to Mediterranean colonies. Our study suggests that a large and admixed population is settling in Galicia, in agreement with predictions from island metapopulation models of colonization. Multiple source colonies imply that some birds colonizing Galicia were dispersing from very distant colonies (> 1500 km). Long-distance colonizations undertaken by relatively large and admixed groups of colonizers can help to explain the low levels of genetic structure over vast areas that are characteristic of most oceanic seabird species. PMID:26909694

  14. Personality and reproductive fitness.

    Science.gov (United States)

    Eaves, L J; Martin, N G; Heath, A C; Hewitt, J K; Neale, M C

    1990-09-01

    The relationship between reproductive success (number of biological children) and personality was explored in 1101 postmenopausal females from the Australian twin registry. The quadratic response surface relating fitness to extraversion (E) and neuroticism (N) showed a saddle point at intermediate levels of E and N. Selection was shown to be stabilizing, i.e., having an intermediate optimum, along the axis low E, low N-high E, high N and more mildly disruptive, having greater fitness in the extremes, along the axis low N, high E-high N, low E. Neither dimension of personality considered by itself showed a significant linear or quadratic relationship to reproductive success. Sections through the fitness surface, however, show selection tends to favor high neuroticism levels in introverts and low neuroticism levels in extroverts. PMID:2288546

  15. FITS Checksum Proposal

    CERN Document Server

    Seaman, Rob; Rots, Arnold

    2012-01-01

    The checksum keywords described here provide an integrity check on the information contained in FITS HDUs. (Header and Data Units are the basic components of FITS files, consisting of header keyword records followed by optional associated data records). The CHECKSUM keyword is defined to have a value that forces the 32-bit 1's complement checksum accumulated over all the 2880-byte FITS logical records in the HDU to equal negative 0. (Note that 1's complement arithmetic has both positive and negative zero elements). Verifying that the accumulated checksum is still equal to -0 provides a fast and fairly reliable way to determine that the HDU has not been modified by subsequent data processing operations or corrupted while copying or storing the file on physical media.

  16. Molecular and biochemical characterization of the major royal jelly protein in bumblebees suggest a non-nutritive function.

    Science.gov (United States)

    Kupke, Jens; Spaethe, Johannes; Mueller, Martin J; Rössler, Wolfgang; Albert, Štefan

    2012-09-01

    Honeybee queens are generated on purpose by extensive feeding with a glandular secretion termed royal jelly. Major royal jelly proteins (MRJPs) are the dominant proteinaceous component of royal jelly. One of them, MRJP1, was found to play a central role in honeybee queen development. Genes encoding MRJPs were reported to originate from a single originator, and several of them have evolved nutritive function. Phylogenetic analysis provides evidence that the same originator has multiplied independently in Nasonia and ant lineages. Here we show that bumblebees represent a transition species preserving a single-copy pre-multiplication stage of MRJP evolution. By exploring the single-copy BtRJPL gene, we found striking similarities with MRJPs of the honeybee such as gene structure and expression regulation. At the same time it turned out that BtRJPL does not fulfill criteria for functioning as a nutritive protein. Instead we found evidence that BtRJPL is involved in food digestion or modification, which appears to be the original MRJP function, at least in this lineage. Thus, the evolutionary pattern of MRJPs in hymenopterans constitutes an excellent example of a functional diversification combined with the origin of new properties followed by intensive gene duplication events. PMID:22617191

  17. The bumblebee Bombus hortorum is the main pollinating visitor to Digitalis purpurea (Common Foxglove in a U.K. population

    Directory of Open Access Journals (Sweden)

    Arthur Broadbent

    2012-06-01

    Full Text Available Specialization in plant-pollinator systems represents an important issue for both the ecological understanding and conservation of these systems. We investigated the extent to which the bumblebee Bombus hortorum (Linnaeus is the main potential pollinator of Common Foxglove, Digitalis purpurea L. Twenty D. purpurea patches were selected in North Yorkshire, U.K., ten each in woodland and garden or park habitat. All insects visiting D. purpurea within the patches were recorded over seventy 30-min bouts. The relative frequency of insect visitors to other flowering plant species within 15 m of each patch was also determined. B. hortorum and B. pascuorum were the two most frequent visitors to D. purpurea, accounting for 82 - 92% and 3 -17%, respectively, of all insect visits (n = 1682, depending on habitat. B. hortorum showed a significant preference for visiting D. purpurea relative to its frequency of visits to other available plant species. The relationship of D. purpurea with B. hortorum, which pollinates several plant species with long corollas, therefore represents a potential case of asymmetric specialization, albeit one that may vary spatially. Because D. purpurea reproduction appears dependent on insect pollination, B. hortorum and B. pascuorum may help underpin the viability of D. purpurea populations.

  18. Recognition and identification of bumblebee species in the Bombus lucorum-complex (Hymenoptera, Apidae – A review and outlook

    Directory of Open Access Journals (Sweden)

    Silas Bossert

    2015-02-01

    Full Text Available The recognition of cryptic species represents one of the major challenges in current taxonomy and affects our understanding of global diversity. In practice, the process from discovery to acceptance in the scientific community can take an extensive length of time. A prime example is the traditionally difficult taxonomy of the cryptic bumblebee species belonging to the Bombus lucorum-complex. The status of the three European species in the group – Bombus lucorum and the closely related Bombus cryptarum and Bombus magnus – has recently become widely accepted, primarily due to investigations of nucleotide sequences and marking pheromones. In contrast, doubts prevail concerning the validity of species identification based on morphology. As a consequence, our knowledge of the species is muddled in a mire of unreliable and confusing literature data from a large number of authors over the centuries. To clarify this issue, this paper provides a recapitulation of the historical literature and highlights the milestones in the process of species recognition. Further, the possibility of a morphologically based species identification is discussed in the context of new molecular data. Finally, this review outlines the current challenges and provides directions for future issues.

  19. Intraspecific variation in flight metabolic rate in the bumblebee Bombus impatiens: repeatability and functional determinants in workers and drones.

    Science.gov (United States)

    Darveau, Charles-A; Billardon, Fannie; Bélanger, Kasandra

    2014-02-15

    The evolution of flight energetics requires that phenotypes be variable, repeatable and heritable. We studied intraspecific variation in flight energetics in order to assess the repeatability of flight metabolic rate and wingbeat frequency, as well as the functional basis of phenotypic variation in workers and drones of the bumblebee species Bombus impatiens. We showed that flight metabolic rate and wingbeat frequency were highly repeatable in workers, even when controlling for body mass variation using residual analysis. We did not detect significant repeatability in drones, but a smaller range of variation might have prevented us from finding significant values in our sample. Based on our results and previous findings, we associated the high repeatability of flight phenotypes in workers to the functional links between body mass, thorax mass, wing size, wingbeat frequency and metabolic rate. Moreover, differences between workers and drones were as predicted from these functional associations, where drones had larger wings for their size, lower wingbeat frequency and lower flight metabolic rate. We also investigated thoracic muscle metabolic phenotypes by measuring the activity of carbohydrate metabolism enzymes, and we found positive correlations between mass-independent metabolic rate and the activity of all enzymes measured, but in workers only. When comparing workers and drones that differ in flight metabolic rate, only the activity of the enzymes hexokinase and trehalase showed the predicted differences. Overall, our study indicates that there should be correlated evolution among physiological phenotypes at multiple levels of organization and morphological traits associated with flight. PMID:24198266

  20. The genotypic structure of a multi-host bumblebee parasite suggests a role for ecological niche overlap.

    Directory of Open Access Journals (Sweden)

    Rahel M Salathé

    Full Text Available The genotypic structure of parasite populations is an important determinant of ecological and evolutionary dynamics of host-parasite interactions with consequences for pest management and disease control. Genotypic structure is especially interesting where multiple hosts co-exist and share parasites. We here analyze the natural genotypic distribution of Crithidia bombi, a trypanosomatid parasite of bumblebees (Bombus spp., in two ecologically different habitats over a time period of three years. Using an algorithm to reconstruct genotypes in cases of multiple infections, and combining these with directly identified genotypes from single infections, we find a striking diversity of infection for both data sets, with almost all multi-locus genotypes being unique, and are inferring that around half of the total infections are resulting from multiple strains. Our analyses further suggest a mixture of clonality and sexuality in natural populations of this parasite species. Finally, we ask whether parasite genotypes are associated with host species (the phylogenetic hypothesis or whether ecological factors (niche overlap in flower choice shape the distribution of parasite genotypes (the ecological hypothesis. Redundancy analysis demonstrates that in the region with relatively high parasite prevalence, both host species identity and niche overlap are equally important factors shaping the distribution of parasite strains, whereas in the region with lower parasite prevalence, niche overlap more strongly contributes to the distribution observed. Overall, our study underlines the importance of ecological factors in shaping the natural dynamics of host-parasite systems.

  1. Performance of Bee Colonies Headed by Queens Instrumentally Inseminated with Semen of Drones Who Come from a Single Colony or Many Colonies

    OpenAIRE

    Gerula Dariusz; Węgrzynowicz Paweł; Panasiuk Beata; Bieńkowska Małgorzata; Skowronek Wojciech

    2014-01-01

    The aim of the study was to determine the effect of honey bee worker diversity within the colony on: development, honey productivity, and wintering. Two different levels of diversity within the colony were tested. The appropriate levels of diversity within the colony were obtained by selecting drones for inseminating the queens. Lower genetic diversity was obtained in the colonies headed by a queen inseminated with semen collected from drones originating from a single colony. Higher genetic d...

  2. Understanding colonial chieftaincy from its final phase

    OpenAIRE

    Keese, Alexander

    2011-01-01

    With the transfers of power in still-colonial sub-Saharan Africa, the epoch of ‘traditional chieftaincy’ seemed to be finally over. The chiefs, frequently regarded by historians and social scientists as a product of the colonial state, appeared to lose all of their authority. Or so it seemed. Fifty years later, we are puzzled by the resilience of chieftaincy in many parts of the African continent. A more profound analysis of chieftaincy in several West African territories under colonial rule...

  3. Colony stage and not facultative policing explains pattern of worker reproduction in the Saxon wasp

    DEFF Research Database (Denmark)

    Bonckaert, W.; van Zweden, Jelle Stijn; D'Ettorre, Patrizia;

    2011-01-01

    policed other workers’ eggs in response to queen mating frequency. Nevertheless, our data do show that the seasonal progression of the nest and the location in which the males were reared both explain the patterns of worker reproduction found. Overall, our results suggest that the earlier evidence for......Inclusive fitness theory predicts that in colonies of social Hymenoptera headed by a multiple-mated queen, workers should benefit from policing eggs laid by other workers. Foster & Ratnieks provided evidence that in the vespine wasp Dolichovespula saxonica, workers police other workers’ eggs only...... in colonies headed by a multiple-mated queen, but not in those headed by a single-mated one. This conclusion, however, was based on a relatively small sample size, and the original study did not control for possible confounding variables such as the seasonal colony progression of the nests. Our aim...

  4. Dumb and Lazy? A Comparison of Color Learning and Memory Retrieval in Drones and Workers of the Buff-Tailed Bumblebee, Bombus terrestris, by Means of PER Conditioning.

    Science.gov (United States)

    Lichtenstein, Leonie; Sommerlandt, Frank M J; Spaethe, Johannes

    2015-01-01

    More than 100 years ago, Karl von Frisch showed that honeybee workers learn and discriminate colors. Since then, many studies confirmed the color learning capabilities of females from various hymenopteran species. Yet, little is known about visual learning and memory in males despite the fact that in most bee species males must take care of their own needs and must find rewarding flowers to obtain food. Here we used the proboscis extension response (PER) paradigm to study the color learning capacities of workers and drones of the bumblebee, Bombus terrestris. Light stimuli were paired with sucrose reward delivered to the insects' antennae and inducing a reflexive extension of the proboscis. We evaluated color learning (i.e. conditioned PER to color stimuli) in absolute and differential conditioning protocols and mid-term memory retention was measured two hours after conditioning. Different monochromatic light stimuli in combination with neutral density filters were used to ensure that the bumblebees could only use chromatic and not achromatic (e.g. brightness) information. Furthermore, we tested if bees were able to transfer the learned information from the PER conditioning to a novel discrimination task in a Y-maze. Both workers and drones were capable of learning and discriminating between monochromatic light stimuli and retrieved the learned stimulus after two hours. Drones performed as well as workers during conditioning and in the memory test, but failed in the transfer test in contrast to workers. Our data clearly show that bumblebees can learn to associate a color stimulus with a sugar reward in PER conditioning and that both workers and drones reach similar acquisition and mid-term retention performances. Additionally, we provide evidence that only workers transfer the learned information from a Pavlovian to an operant situation. PMID:26230643

  5. Dumb and Lazy? A Comparison of Color Learning and Memory Retrieval in Drones and Workers of the Buff-Tailed Bumblebee, Bombus terrestris, by Means of PER Conditioning.

    Directory of Open Access Journals (Sweden)

    Leonie Lichtenstein

    Full Text Available More than 100 years ago, Karl von Frisch showed that honeybee workers learn and discriminate colors. Since then, many studies confirmed the color learning capabilities of females from various hymenopteran species. Yet, little is known about visual learning and memory in males despite the fact that in most bee species males must take care of their own needs and must find rewarding flowers to obtain food. Here we used the proboscis extension response (PER paradigm to study the color learning capacities of workers and drones of the bumblebee, Bombus terrestris. Light stimuli were paired with sucrose reward delivered to the insects' antennae and inducing a reflexive extension of the proboscis. We evaluated color learning (i.e. conditioned PER to color stimuli in absolute and differential conditioning protocols and mid-term memory retention was measured two hours after conditioning. Different monochromatic light stimuli in combination with neutral density filters were used to ensure that the bumblebees could only use chromatic and not achromatic (e.g. brightness information. Furthermore, we tested if bees were able to transfer the learned information from the PER conditioning to a novel discrimination task in a Y-maze. Both workers and drones were capable of learning and discriminating between monochromatic light stimuli and retrieved the learned stimulus after two hours. Drones performed as well as workers during conditioning and in the memory test, but failed in the transfer test in contrast to workers. Our data clearly show that bumblebees can learn to associate a color stimulus with a sugar reward in PER conditioning and that both workers and drones reach similar acquisition and mid-term retention performances. Additionally, we provide evidence that only workers transfer the learned information from a Pavlovian to an operant situation.

  6. Making the Fitness Connection

    Science.gov (United States)

    Brock, Sheri J.; Fittipaldi-Wert, Jeanine

    2005-01-01

    Children's fitness levels are decreasing at an alarming rate. The Centers for Disease Control has determined that approximately 33% of children do not regularly engage in vigorous physical activity (CDC, 2002). As a result, childhood obesity has increased 100% since 1980 in the United States due to physical inactivity (CDC, 2004). A well-planned…

  7. Fit for work

    DEFF Research Database (Denmark)

    Brorholt, Grete

    "Fit for work - Attraktiv sundhed og sikkerhed på en hospitalsafdeling i Region Hovedstaden" undersøger hvorledes sundhedsvæsenets forandringer påvirker medarbejdere, ledere og organisation. Udgangspunktet for afhandlingen er en interesse for psykisk arbejdsmiljø, og hvordan reformerne i kølvandet...

  8. Teaching Aerobic Fitness Concepts.

    Science.gov (United States)

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  9. Optical image acquisition system for colony analysis

    Science.gov (United States)

    Wang, Weixing; Jin, Wenbiao

    2006-02-01

    For counting of both colonies and plaques, there is a large number of applications including food, dairy, beverages, hygiene, environmental monitoring, water, toxicology, sterility testing, AMES testing, pharmaceuticals, paints, sterile fluids and fungal contamination. Recently, many researchers and developers have made efforts for this kind of systems. By investigation, some existing systems have some problems since they belong to a new technology product. One of the main problems is image acquisition. In order to acquire colony images with good quality, an illumination box was constructed as: the box includes front lightning and back lightning, which can be selected by users based on properties of colony dishes. With the illumination box, lightning can be uniform; colony dish can be put in the same place every time, which make image processing easy. A digital camera in the top of the box connected to a PC computer with a USB cable, all the camera functions are controlled by the computer.

  10. Growth and form of melanoma cell colonies

    International Nuclear Information System (INIS)

    We study the statistical properties of melanoma cell colonies grown in vitro by analyzing the results of crystal violet assays at different concentrations of initial plated cells and for different growth times. The distribution of colony sizes is described well by a continuous time branching process. To characterize the shape fluctuations of the colonies, we compute the distribution of eccentricities. The experimental results are compared with numerical results for models of random division of elastic cells, showing that experimental results are best reproduced by restricting cell division to the outer rim of the colony. Our results serve to illustrate the wealth of information that can be extracted by a standard experimental method such as the crystal violet assay. (paper)

  11. Bacterial colony counting by Convolutional Neural Networks.

    Science.gov (United States)

    Ferrari, Alessandro; Lombardi, Stefano; Signoroni, Alberto

    2015-08-01

    Counting bacterial colonies on microbiological culture plates is a time-consuming, error-prone, nevertheless fundamental task in microbiology. Computer vision based approaches can increase the efficiency and the reliability of the process, but accurate counting is challenging, due to the high degree of variability of agglomerated colonies. In this paper, we propose a solution which adopts Convolutional Neural Networks (CNN) for counting the number of colonies contained in confluent agglomerates, that scored an overall accuracy of the 92.8% on a large challenging dataset. The proposed CNN-based technique for estimating the cardinality of colony aggregates outperforms traditional image processing approaches, becoming a promising approach to many related applications. PMID:26738016

  12. Cephalic secretions of the bumblebee subgenus Sibiricobombus Vogt suggest Bombus niveatus Kriechbaumer and Bombus vorticosus Gerstaecker are conspecific (Hymenoptera, Apidae, Bombus)

    OpenAIRE

    Rasmont, Pierre; Terzo, Michaël; Murat Aytekin, A.; Hines, Heather; Urbanova, Klara; Cahlikova, L.; Valterova, Irena

    2005-01-01

    Three taxa of the subgenus Sibiricobombus live in the Near-East mountain steppes: Bombus niveatus, B. sulfureus and B. vorticosus. The latter is also present in the Balkan. B. niveatus and B. vorticosus can only be distinguished based on color pattern. B. sulfureus differs in coat color and in genitalia. We identified 40 compounds in the secretions of the labial glands of these taxa, among which 7 were detected for the first time in labial cephalic gland secretions of bumblebee males. Whereas...

  13. Pattern Formation in a Bacterial Colony Model

    OpenAIRE

    2013-01-01

    We investigate the spatiotemporal dynamics of a bacterial colony model. Based on the stability analysis, we derive the conditions for Hopf and Turing bifurcations. Furthermore, we present novel numerical evidence of time evolution of patterns controlled by parameters in the model and find that the model dynamics exhibit a diffusion controlled formation growth to spots, holes and stripes pattern replication, which show that the bacterial colony model is useful in revealing the spatial predatio...

  14. Pattern Formation in a Bacterial Colony Model

    Directory of Open Access Journals (Sweden)

    Xinze Lian

    2014-01-01

    Full Text Available We investigate the spatiotemporal dynamics of a bacterial colony model. Based on the stability analysis, we derive the conditions for Hopf and Turing bifurcations. Furthermore, we present novel numerical evidence of time evolution of patterns controlled by parameters in the model and find that the model dynamics exhibit a diffusion controlled formation growth to spots, holes and stripes pattern replication, which show that the bacterial colony model is useful in revealing the spatial predation dynamics in the real world.

  15. Automatic Programming with Ant Colony Optimization

    OpenAIRE

    Green, Jennifer; Jacqueline L. Whalley; Johnson, Colin G.

    2004-01-01

    Automatic programming is the use of search techniques to find programs that solve a problem. The most commonly explored automatic programming technique is genetic programming, which uses genetic algorithms to carry out the search. In this paper we introduce a new technique called Ant Colony Programming (ACP) which uses an ant colony based search in place of genetic algorithms. This algorithm is described and compared with other approaches in the literature.

  16. Eutectic colony formation: A phase field study

    OpenAIRE

    Plapp, Mathis; Karma, Alain

    2001-01-01

    Eutectic two-phase cells, also known as eutectic colonies, are commonly observed during the solidification of ternary alloys when the composition is close to a binary eutectic valley. In analogy with the solidification cells formed in dilute binary alloys, colony formation is triggered by a morphological instability of a macroscopically planar eutectic solidification front due to the rejection by both solid phases of a ternary impurity that diffuses in the liquid. Here we develop a phase-fiel...

  17. Influence of feeding bee colonies on colony strenght and honey authenticity

    OpenAIRE

    Andreja KANDOLF BOROVŠAK; Ogrinc, Nives; Lilek, Nataša; Boštjan NOČ; Božič, Janko; Korošec, Mojca

    2015-01-01

    For the natural development of bee colonies, there is the need for appropriate nutrition. Lack of natural honey flow must be supplemented by feeding bee colonies with sugar syrups or candy paste. This supplementary feeding encourages brood breeding and forage activity, whereby stronger colonies collect more honey. Sugar syrups can cause honey adulteration, which is more frequent with the reversing of the brood combs with the bee food, with the combs moved from the brood chamber to the upper c...

  18. ColonyArea: An ImageJ Plugin to Automatically Quantify Colony Formation in Clonogenic Assays

    OpenAIRE

    Guzmán, Camilo; Bagga, Manish; Kaur, Amanpreet; Westermarck, Jukka; Abankwa, Daniel

    2014-01-01

    The clonogenic or colony formation assay is a widely used method to study the number and size of cancer cell colonies that remain after irradiation or cytotoxic agent administration and serves as a measure for the anti-proliferative effect of these treatments. Alternatively, this assay is used to quantitate the transforming potential of cancer associated genes and chemical agents. Therefore, there is a need for a simplified and standardized analysis of colony formation assays for both routine...

  19. ColonyArea: an ImageJ plugin to automatically quantify colony formation in clonogenic assays.

    Directory of Open Access Journals (Sweden)

    Camilo Guzmán

    Full Text Available The clonogenic or colony formation assay is a widely used method to study the number and size of cancer cell colonies that remain after irradiation or cytotoxic agent administration and serves as a measure for the anti-proliferative effect of these treatments. Alternatively, this assay is used to quantitate the transforming potential of cancer associated genes and chemical agents. Therefore, there is a need for a simplified and standardized analysis of colony formation assays for both routine laboratory use and for parallelized automated analysis. Here we describe the freely available ImageJ-plugin "ColonyArea", which is optimized for rapid and quantitative analysis of focus formation assays conducted in 6- to 24-well dishes. ColonyArea processes image data of multi-well dishes, by separating, concentrically cropping and background correcting well images individually, before colony formation is quantitated. Instead of counting the number of colonies, ColonyArea determines the percentage of area covered by crystal violet stained cell colonies, also taking the intensity of the staining and therefore cell density into account. We demonstrate that these parameters alone or in combination allow for robust quantification of IC50 values of the cytotoxic effect of two staurosporines, UCN-01 and staurosporine (STS on human glioblastoma cells (T98G. The relation between the potencies of the two compounds compared very well with that obtained from an absorbance based method to quantify colony growth and to published data. The ColonyArea ImageJ plugin provides a simple and efficient analysis routine to quantitate assay data of one of the most commonly used cellular assays. The bundle is freely available for download as supporting information. We expect that ColonyArea will be of broad utility for cancer biologists, as well as clinical radiation scientists.

  20. Reproductive competition in the bumble-bee Bombus terrestris: do workers advertise sterility?

    Science.gov (United States)

    Amsalem, Etya; Twele, Robert; Francke, Wittko; Hefetz, Abraham

    2009-04-01

    Reproductive competition in social insects is generally mediated through specific fertility pheromones. By analysing Dufour's gland secretion in queens and workers of Bombus terrestris under varying social conditions, we demonstrate here that the volatile constituents of the secretion exhibit a context-dependent composition. The secretion of egg-laying queens is composed of a series of aliphatic hydrocarbons (alkanes and alkenes), while that of sterile workers contains in addition octyl esters, dominated by octyl hexadecanoate and octyl oleate. These esters disappear in workers with developed ovaries, whether queenright (QR) or queenless (QL), rendering their secretion queen-like. This constitutes an unusual case in which the sterile caste, rather than the fertile one, possesses extra components. Individually isolated (socially deprived) workers developed ovaries successfully, but failed to oviposit, and still possessed the octyl esters. Thus, whereas social interactions are not needed in order to develop ovaries, they appear essential for oviposition and compositional changes in Dufour's gland secretion (ester disappearance). The apparent link between high ester levels and an inability to lay eggs lends credence to the hypothesis that these esters signal functional sterility. We hypothesize that by producing a sterility-specific secretion, workers signal that 'I am out of the competition', and therefore are not attacked, either by the queen or by the reproductive workers. This enables proper colony function and brood care, in particular sexual brood, even under the chaotic conditions of the competition phase. PMID:19129137

  1. Human myeloma in vitro colony growth

    International Nuclear Information System (INIS)

    Human myeloma stem cells were examined by their capacity to form colonies in culture. Cells separated from bone marrow of 15 patients with multiple myeloma were cultured in semi-solid methylcellulose with conditioned medium obtained from cultured T lymphocytes stimulated by phytohemagglutinin. The number of colonies consisting of more than 20 cells was counted after 10 days of culture. The colonies formed consisted mostly of lymphoplasmacytoid or plasma cells, and the immunoglobulin in the cytoplasm of cells from colonies was identical to that found in cells used for culture. The number of colonies formed was proportional to the number of cells plated. These results suggested that the cells in the colonies were derived from the myeloma cells originally used. The proportion of myeloma stem cells in the proliferative state was examined in 12 patients by the suicide method using [3H]-TdR and the results were between 21 and 75 %, the mean value being approximately 40 %. The irradiation sensitivity of myeloma stem cells was examined by the 60Co-γ-irradiation method. The mean Do value in 7 cases was 116 rads and the mean extrapolation number was 2.0. An inverse relationship was observed between the Do value and the proportion of cells in the S phase. (author)

  2. Periodic Pattern Formation of Bacterial Colonies

    Science.gov (United States)

    Itoh, Hiroto; Wakita, Jun-ichi; Matsuyama, Tohey; Matsushita, Mitsugu

    1999-04-01

    We have experimentally investigated pattern formation of colonies ofbacterial species Proteus mirabilis, which is famous forforming concentric-ring-like colonies.The colony grows cyclically with the interface repeating an advance anda stop alternately on a surface of a solid agar medium.We distinguish three phases (initial lag phase, the followingmigration and consolidation phases that appear alternately) for the colony growth.When we cut a colony just behind a migrating front shortly after the migrationstarted, the migration ended earlier and the following consolidationlasted longer.However, the following cycles were not influenced by the cut, i.e., thephases of the migration and consolidation were not affected.Global chemical signals governing the colony formation from thecenter were not found to exist.We also quantitatively checked phase entrainment by letting two coloniescollide with each other and found that it does not take place in macroscopic scales.All these experimental results suggest that the most important factorfor the migration is the cell population density.

  3. Wavelet phase estimation using ant colony optimization algorithm

    Science.gov (United States)

    Wang, Shangxu; Yuan, Sanyi; Ma, Ming; Zhang, Rui; Luo, Chunmei

    2015-11-01

    Eliminating seismic wavelet is important in seismic high-resolution processing. However, artifacts may arise in seismic interpretation when the wavelet phase is inaccurately estimated. Therefore, we propose a frequency-dependent wavelet phase estimation method based on the ant colony optimization (ACO) algorithm with global optimization capacity. The wavelet phase can be optimized with the ACO algorithm by fitting nearby-well seismic traces with well-log data. Our proposed method can rapidly produce a frequency-dependent wavelet phase and optimize the seismic-to-well tie, particularly for weak signals. Synthetic examples demonstrate the effectiveness of the proposed ACO-based wavelet phase estimation method, even in the presence of a colored noise. Real data example illustrates that seismic deconvolution using an optimum mixed-phase wavelet can provide more information than that using an optimum constant-phase wavelet.

  4. Improvised Scout Bee Movements in Artificial Bee Colony

    Directory of Open Access Journals (Sweden)

    Tarun Kumar Sharma

    2014-01-01

    Full Text Available In the basic Artificial Bee Colony (ABC algorithm, if the fitness value associated with a food source is not improved for a certain number of specified trials then the corresponding bee becomes a scout to which a random value is assigned for finding the new food source. Basically, it is a mechanism of pulling out the candidate solution which may be entrapped in some local optimizer due to which its value is not improving. In the present study, we propose two new mechanisms for the movements of scout bees. In the first method, the scout bee follows a non-linear interpolated path while in the second one, scout bee follows Gaussian movement. Numerical results and statistical analysis of benchmark unconstrained, constrained and real life engineering design problems indicate that the proposed modifications enhance the performance of ABC.

  5. Ecology and multilevel selection explain aggression in spider colonies.

    Science.gov (United States)

    Biernaskie, Jay M; Foster, Kevin R

    2016-08-01

    Progress in sociobiology continues to be hindered by abstract debates over methodology and the relative importance of within-group vs. between-group selection. We need concrete biological examples to ground discussions in empirical data. Recent work argued that the levels of aggression in social spider colonies are explained by group-level adaptation. Here, we examine this conclusion using models that incorporate ecological detail while remaining consistent with kin- and multilevel selection frameworks. We show that although levels of aggression are driven, in part, by between-group selection, incorporating universal within-group competition provides a striking fit to the data that is inconsistent with pure group-level adaptation. Instead, our analyses suggest that aggression is favoured primarily as a selfish strategy to compete for resources, despite causing lower group foraging efficiency or higher risk of group extinction. We argue that sociobiology will benefit from a pluralistic approach and stronger links between ecologically informed models and data. PMID:27264438

  6. A hybrid ant colony algorithm for loading pattern optimization

    International Nuclear Information System (INIS)

    EDF (Electricity of France) operates 58 nuclear power plant (NPP), all of the Pressurized Water Reactor (PWR) type. The loading pattern (LP) optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF has developed automatic optimization tools that assist the experts. This paper presents firstly a description of the LP optimization problem listing its constraints. Secondly, a study of the search space is performed using the 'landscape fitness analysis' paradigm. Lastly, a hybrid algorithm based on ant colony and a local search method, is introduced to take advantage of the features of the problem. Tests have been performed on realistic cases. This hybrid algorithm has turned out to give very encouraging results when compared to a randomized local search method

  7. Ant colony optimization approach to estimate energy demand of Turkey

    International Nuclear Information System (INIS)

    This paper attempts to shed light on the determinants of energy demand in Turkey. Energy demand model is first proposed using the ant colony optimization (ACO) approach. It is multi-agent systems in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. ACO energy demand estimation (ACOEDE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear and quadratic. QuadraticACOEDE provided better-fit solution due to fluctuations of the economic indicators. The ACOEDE model plans the energy demand of Turkey until 2025 according to three scenarios. The relative estimation errors of the ACOEDE model are the lowest when they are compared with the Ministry of Energy and Natural Resources (MENR) projection

  8. Local search heuristics: Fitness Cloud versus Fitness Landscape

    OpenAIRE

    Collard, Philippe; Verel, Sébastien; Clergue, Manuel

    2004-01-01

    International audience This paper introduces the concept of fitness cloud as an alternative way to visualize and analyze search spaces than given by the geographic notion of fitness landscape. It is argued that the fitness cloud concept overcomes several deficiencies of the landscape representation. Our analysis is based on the correlation between fitness of solutions and fitnesses of nearest solutions according to some neighboring. We focus on the behavior of local search heuristics, such...

  9. Yeast Colony Survival Depends on Metabolic Adaptation and Cell Differentiation Rather Than on Stress Defense*

    OpenAIRE

    Čáp, Michal; Váchová, Libuše; Palková, Zdena

    2009-01-01

    Enzymes scavenging reactive oxygen species (ROS) are important for cell protection during stress and aging. A deficiency in these enzymes leads to ROS imbalance, causing various disorders in many organisms, including yeast. In contrast to liquid cultures, where fitness of the yeast population depends on its ROS scavenging capability, the present study suggests that Saccharomyces cerevisiae cells growing in colonies capable of ammonia signaling use a broader protective strategy. Instead of mai...

  10. BESⅢ track fitting algorithm

    Institute of Scientific and Technical Information of China (English)

    WANG Ji-Ke; MAO Ze-Pu; BIAN Jian-Ming; CAO Guo-Fu; CAO Xue-Xiang; CHEN Shen-Jian; DENG Zi-Yan; FU Cheng-Dong; GAO Yuan-Ning; HE Kang-Lin; HE Miao; HUA Chun-Fei; HUANG Bin; HUANG Xing-Tao; JI Xiao-Sin; LI Fei; LI Hai-Bo; LI Wei-Dong; LIANG Yu-Tie; LIU Chun-Xiu; LIU Huai-Min; LIU Suo; LIU Ying-Jie; MA Qiu-Mei; MA Xiang; MAO Ya-Jun; MO Xiao-Hu; PAN Ming-Hua; PANG Cai-Ying; PING Rong-Gang; QIN Ya-Hong; QIU Jin-Fa; SUN Sheng-Sen; SUN Yong-Zhao; WANG Liang-Liang; WEN Shuo-Pin; WU Ling-Hui; XIE Yu-Guang; XU Min; YAN Liang; YOU Zheng-Yun; YUAN Chang-Zheng; YUAN Ye; ZHANG Bing-Yun; ZHANG Chang-Chun; ZHANG Jian-Yong; ZHANG Xue-Yao; ZHANG Yao; ZHENG Yang-Heng; ZHU Ke-Jun; ZHU Yong-Sheng; ZHU Zhi-Li; ZOU Jia-Heng

    2009-01-01

    A track fitting algorithm based on the Kalman filter method has been developed for BESⅢ of BEPCⅡ.The effects of multiple scattering and energy loss when the charged particles go through the detector,non-uniformity of magnetic field (NUMF) and wire sag, etc., have been carefully handled.This algorithm works well and the performance satisfies the physical requirements tested by the simulation data.

  11. Physical Fitness and Pregnancy

    OpenAIRE

    Thorell, Eva

    2013-01-01

    Objectives To assess physical fitness in pregnancy and to evaluate its effect on perceived health, back pain, blood pressure and duration of gestation. Also, to evaluate the effect of serum relaxin levels on blood pressure and duration of gestation. Material and methods A prospective cohort of 520 pregnant women were examined in early pregnancy and five months postpartum with regard to socio-demographic characteristics and estimated peak oxygen uptake (V̇O2 peak, est.). Serum concentrations o...

  12. Fitness and employee productivity.

    Science.gov (United States)

    Howard, J; Mikalachki, A

    1979-09-01

    What should management consider when deciding whether to sponsor a company fitness program? This article gives pragmatic answers to the business community as well as outlining critical avenues for future research for both academics and corporations. Understanding the nature of the commitment is a prerequisite for success. Whether the program should be short term and serve as a catalyst for future individual efforts, or a long-term commitment, is a question which must be considered. Decisions of this type are partially dependent on what criteria are used to evaluate success. As measurements of employee productivity are very subjective or non-existent, absenteeism and turnover are potential yardsticks. Details of employee programs must also address the issue of participation as well as the frequency, intensity and duration. Future research must separate the effect of the fitness improvement from the benfits derived from just being in a program. The measurement of productivity and the long-term effect of fitness programs, especially short-term programs, are also areas for future work. PMID:540412

  13. Made to fit

    DEFF Research Database (Denmark)

    Bjerck, Mari; Klepp, Ingun Grimstad; Skoland, Eli

    Denne rapporten formidler funn fra en litteraturstudie, brukerundersøkelse og markedsundersøkelse gjort i prosjektet Made to Fit. Rapporten svarer på prosjektets hovedmål og delmål som retter seg mot å formidle kunnskap om tilpasning og fremstilling av funksjonelle og gode produkter for handikapp......Denne rapporten formidler funn fra en litteraturstudie, brukerundersøkelse og markedsundersøkelse gjort i prosjektet Made to Fit. Rapporten svarer på prosjektets hovedmål og delmål som retter seg mot å formidle kunnskap om tilpasning og fremstilling av funksjonelle og gode produkter for...... handikappede. Herunder potensialet for å utvikle spesialtilpassede klær i konseptet «Made to Fit», utprøving av metoder og identifisering av kunnskapsstatus på feltet. Rapporten er således delt inn i tre hoveddeler. Første delen bygger videre på prosjektnotatet til Vestvik, Hebrok og Klepp (2013) fra...

  14. Extensive fitness and human cooperation

    NARCIS (Netherlands)

    van Hateren, J. H.

    2015-01-01

    Evolution depends on the fitness of organisms, the expected rate of reproducing. Directly getting offspring is the most basic form of fitness, but fitness can also be increased indirectly by helping genetically related individuals (such as kin) to increase their fitness. The combined effect is known

  15. Photoreceptor processing speed and input resistance changes during light adaptation correlate with spectral class in the bumblebee, Bombus impatiens.

    Directory of Open Access Journals (Sweden)

    Peter Skorupski

    Full Text Available Colour vision depends on comparison of signals from photoreceptors with different spectral sensitivities. However, response properties of photoreceptor cells may differ in ways other than spectral tuning. In insects, for example, broadband photoreceptors, with a major sensitivity peak in the green region of the spectrum (>500 nm, drive fast visual processes, which are largely blind to chromatic signals from more narrowly-tuned photoreceptors with peak sensitivities in the blue and UV regions of the spectrum. In addition, electrophysiological properties of the photoreceptor membrane may result in differences in response dynamics of photoreceptors of similar spectral class between species, and different spectral classes within a species. We used intracellular electrophysiological techniques to investigate response dynamics of the three spectral classes of photoreceptor underlying trichromatic colour vision in the bumblebee, Bombus impatiens, and we compare these with previously published data from a related species, Bombus terrestris. In both species, we found significantly faster responses in green, compared with blue- or UV-sensitive photoreceptors, although all 3 photoreceptor types are slower in B. impatiens than in B. terrestris. Integration times for light-adapted B. impatiens photoreceptors (estimated from impulse response half-width were 11.3 ± 1.6 ms for green photoreceptors compared with 18.6 ± 4.4 ms and 15.6 ± 4.4 for blue and UV, respectively. We also measured photoreceptor input resistance in dark- and light-adapted conditions. All photoreceptors showed a decrease in input resistance during light adaptation, but this decrease was considerably larger (declining to about 22% of the dark value in green photoreceptors, compared to blue and UV (41% and 49%, respectively. Our results suggest that the conductances associated with light adaptation are largest in green photoreceptors, contributing to their greater temporal processing speed

  16. Varroa-Virus Interaction in Collapsing Honey Bee Colonies

    OpenAIRE

    Francis, Roy M; NIELSEN, STEEN L.; Per Kryger

    2013-01-01

    Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI) and Deformed Wing Virus (DWV)) were monitored in a year-long study. We investigated the viral titres in honey bees and varroa mites from 23 colonies (15 apiaries) under three treatment conditions: Organic acids (11 colonies), pyrethroid (9 colonies) and untreated (3 colonies). Approximately 200 bees were ...

  17. The makeshift settlement: colonial policy in British West Africa

    OpenAIRE

    Phillips, A M

    1982-01-01

    This thesis examines the evolution of colonial policy within British West Africa, and is based largely on unpublished correspondence between the Colonial office and colonial governors, held in the Public Record Office in London. It argues that the colonial states were unable to generate or implement a satisfactory strategy for capitalist development. In the first twenty years of colonial rule, various projects were outlined, which assumed the introduction of private property in land, the enco...

  18. Colony collapse disorder: a descriptive study.

    Directory of Open Access Journals (Sweden)

    Dennis Vanengelsdorp

    Full Text Available BACKGROUND: Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L. colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. METHODS AND PRINCIPAL FINDINGS: Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels, no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor were higher in control colonies than CCD-affected colonies. CONCLUSIONS/SIGNIFICANCE: This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted.

  19. Ant colony optimization algorithm for continuous domains based on position distribution model of ant colony foraging.

    Science.gov (United States)

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm. PMID:24955402

  20. Fitting of Z' parameters

    OpenAIRE

    Gulov, Alexey; Skalozub, Vladimir

    2010-01-01

    The paper deals with an approach to the model-independent searching for the Z' gauge boson as a virtual state in scattering processes. The relations between the Z' couplings to fermions covering a wide class of models beyond the standard model are found and used. They reduce in an essential way the number of parameters to be fitted in experiments. Special observables which uniquely pick out the Z' at energies of LEP and ILC colliders in different leptonic processes are introduced and the data...

  1. Colony location algorithm for assignment problems

    Institute of Scientific and Technical Information of China (English)

    Dingwei WANG

    2004-01-01

    A novel algorithm called Colony Location Algorithm (CLA) is proposed. It mimics the phenomena in biotic conmunity that colonies of species could be located in the places most suitable to their growth. The factors working on the species location such as the nutrient of soil, resource competition between species, growth and decline process, and effect on environment were considered in CLA via the nutrient function, growth and decline rates, environment evaluation and fertilization strategy.CLA was applied to solve the classical assignment problems. The computation results show that CLA can achieve the optimal solution with higher possibility and shorter running time.

  2. Print, Newspapers and Audiences in Colonial Kenya

    DEFF Research Database (Denmark)

    Frederiksen, Bodil Folke

    2011-01-01

    The article addresses African and Indian newspaper networks in Kenya in the late 1940s in an Indian Ocean perspective. Newspapers were important parts of a printing culture that was sustained by Indian and African nationalist politics and economic enterprise. In this period new intermediary groups...... of view in newspapers. They depended on voluntary and political associations and anti-colonial struggles in Kenya and on links to nationalists in India and the passive resistance movement in South Africa. They sidestepped the European-dominated print culture and created an anti-colonial counter...

  3. Monoclonal origin of B lymphocyte colony-forming cells in spleen colonies formed by multipotential hemopoietic stem cells

    Science.gov (United States)

    Lala, PK; Johnson, GR

    1978-01-01

    Spleen colonies produced by transplanting lethally irradiated mice with either 12 day fetal liver or adult bone marrow cells were found to contain B- lymphocyte colony-forming cells (BL-CFC) . The proportion of BL-CFC positive spleen colonies did not increase substantially between 8 and 14 days after transplantation, the range being 18-45 percent. However, the absolute number of BL-CFC per spleen colony varied considerably (between 1 and 10,318), although the majority of colonies contained less than 200 BL-CFC. Irrespective of the time after transplantation, smaller spleen colonies were found to have a higher frequency of BL-CFC than larger spleen colonies. To determine the possible clonal origin of BL-CFC from spleen colony- forming unit (CFU-S), CBA mice were injected with equal numbers of CBA and CBA T(6)/T(6) fetal liver or adult bone marrow cells. Analysis of 7-15-day spleen colonies demonstrated that 90 percent were either exclusively T(6) positive or T(6) negative and approximately equal numbers ofboth colony types were observed. B-lymphocyte colonies were grown and successfully karyotyped from 19 spleen colonies. When compared with the original spleen colony karyotype the B-lymphocyte colony cells karyotype was identical in all 19 cases. In 3 of the 19 colonies analyzed a mixture of T(6) positive and T(6) negative karyotypes was present and identical proportions of the karyotypes were present in the pooled B-lymphocyte colony cells and spleen colony cells. The data indicate that the B-lymphocyte colony-forming cells detected in spleen colonies are genuine members of the hemopoietic clone derived from the initiating hemopoietic stem cell (CFU-S). PMID:309918

  4. Population and colony-level determinants of tertiary sex ratio in the declining barn swallow.

    Directory of Open Access Journals (Sweden)

    Nicola Saino

    Full Text Available Sex ratio of adults (tertiary sex ratio, TSR is a major feature of animal populations with consequences for their behaviour, genetic structure and viability. Spatial and temporal variation in TSR occurs within species but the mechanisms behind it are poorly understood. In this long-term study of a declining population of a socially monogamous, colonial, migratory bird, the barn swallow (Hirundo rustica, we first analyzed population-level variation in TSR ( =  proportion of males of yearlings at sexual maturation in relation to ecological conditions as gauged by annual survival rate of adults. TSR was male-biased both among yearlings and older individuals, but male bias of yearlings was more pronounced after years with larger decline in adult survival. Thus, male offspring were less susceptible to the adverse ecological conditions that cause increased mortality. Dispersal and settling site decisions can have major consequences on fitness via the effects of local TSR on mating and sperm competition. Breeding barn swallows are highly philopatric while natal dispersal is high and, together with mortality, is the main determinant of colony TSR. We thus also investigated the mechanisms of breeding colony choice by yearlings and found that TSR of new-settlers in a given colony and year was negatively predicted by TSR of returning, early arriving older individuals in that year, but not by overall TSR at the colony in the previous year. This suggests that in our male-biased population new-settler males respond to local TSR upon arrival to choose the sites with larger breeding opportunities. Hence, variation in ecological conditions as reflected by adult survival can shift the TSR of individuals recruiting into a local population, with potentially various demographic consequences. However, breeding site choice based on TSR tends to homogenize TSR at a population level likely by facilitating settling of dispersing males in colonies with less male

  5. Automatic software fault localization based on ar tificial bee colony

    Institute of Scientific and Technical Information of China (English)

    Linzhi Huang∗; Jun Ai

    2015-01-01

    Software debugging accounts for a vast majority of the financial and time costs in software developing and maintenance. Thus, approaches of software fault localization that can help au-tomate the debugging process have become a hot topic in the field of software engineering. Given the great demand for software fault localization, an approach based on the artificial bee colony (ABC) algorithm is proposed to be integrated with other related techniques. In this process, the source program is initial y instru-mented after analyzing the dependence information. The test case sets are then compiled and run on the instrumented program, and execution results are input to the ABC algorithm. The algorithm can determine the largest fitness value and best food source by calculating the average fitness of the employed bees in the iter-ative process. The program unit with the highest suspicion score corresponding to the best test case set is regarded as the final fault localization. Experiments are conducted with the TCAS program in the Siemens suite. Results demonstrate that the proposed fault localization method is effective and efficient. The ABC algorithm can efficiently avoid the local optimum, and ensure the validity of the fault location to a larger extent.

  6. Fitness consequences of timing of migration and breeding in cormorants.

    Directory of Open Access Journals (Sweden)

    Phillip Gienapp

    Full Text Available In most bird species timing of breeding affects reproductive success whereby early breeding is favoured. In migratory species migration time, especially arrival at the breeding grounds, and breeding time are expected to be correlated. Consequently, migration time should also have fitness consequences. However, in contrast to breeding time, evidence for fitness consequences of migration time is much more limited. Climate change has been shown to negatively affect the synchrony between trophic levels thereby leading to directional selection on timing but again direct evidence in avian migration time is scarce. We here analysed fitness consequences of migration and breeding time in great cormorants and tested whether climate change has led to increased selection on timing using a long-term data set from a breeding colony on the island of Vorsø (Denmark. Reproductive success, measured as number of fledglings, correlated with breeding time and arrival time at the colony and declined during the season. This seasonal decline became steeper during the study period for both migration and breeding time and was positively correlated to winter/spring climate, i.e. selection was stronger after warmer winters/springs. However, the increasing selection pressure on timing seems to be unrelated to climate change as the climatic variables that were related to selection strength did not increase during the study period. There is indirect evidence that phenology or abundances of preferred prey species have changed which could have altered selection on timing of migration and breeding.

  7. Dance Your Way to Fitness

    Science.gov (United States)

    ... ency/patientinstructions/000809.htm Dance Your Way to Fitness To use the sharing features on this page, ... to rhythm and music. Many health clubs and fitness centers offer dance workout classes, such as Zumba. ...

  8. Dance Your Way to Fitness

    Science.gov (United States)

    ... to rhythm and music. Many health clubs and fitness centers offer dance workout classes, such as Zumba. ... vigorous program for people of all ability and fitness levels. Dance video games and DVDs are also ...

  9. RICE IN COLONIAL AND POST COLONIAL SOUTHEAST ASIA: A FOOD REGIME ANALYSIS

    OpenAIRE

    Dias Pradadimara

    2015-01-01

    This paper traces the ways in which rice, as a global commodity, has been produced and sold in various regions in Southeast Asia from the colonial era to the present days. This paper employs a food regime analysis first introduced by Harriet Friedmann (1982) and later developed together with Philip McMichael (1989) to look at the global political economy of rice. In this paper, it will be shown how various colonial and post colonial states in Southeast Asia (including Thailand who was never f...

  10. Fitness for All: Conceptual Considerations.

    Science.gov (United States)

    Lockhart, Barbara D.

    1994-01-01

    Article proposes concepts that could be the basis for fitness attitudes and practices for all people regardless of skill, age, or expertise. An intrinsic definition of fitness highlights the importance of exercise and relaxation to fitness, integration of the whole self, and acceptance of self based on inherent worth. (SM)

  11. Performance of Bee Colonies Headed by Queens Instrumentally Inseminated with Semen of Drones Who Come from a Single Colony or Many Colonies

    Directory of Open Access Journals (Sweden)

    Gerula Dariusz

    2014-12-01

    Full Text Available The aim of the study was to determine the effect of honey bee worker diversity within the colony on: development, honey productivity, and wintering. Two different levels of diversity within the colony were tested. The appropriate levels of diversity within the colony were obtained by selecting drones for inseminating the queens. Lower genetic diversity was obtained in the colonies headed by a queen inseminated with semen collected from drones originating from a single colony. Higher genetic diversity was obtained in the colonies with queens inseminated with semen from drones of 30 different colonies. Colonies with a higher genetic variation of workers in the colonies had greater levels of functional characteristics. However, apart from the number of dead bees in winter, the genetic diversity level of the workers on the colony development and honey production, did not have a significant influence. There was an averaging effect observed concerning that male component in the colonies with a higher genetic variation of workers - on honey yield, when compared to the non-additive effect of the best drones.

  12. Education and Evangelism in the English Colonies

    Science.gov (United States)

    Watras, Joseph

    2008-01-01

    This article considers two related educational endeavors of the Massachusetts colony. The first is the colonists' efforts to pass their religious traditions to their children. The second is the effort of missionaries to spread the Christian faith to Native Americans. In both cases, the colonists wanted their children and the American Indians to…

  13. A Bicentennial Without a Puerto Rican Colony

    Science.gov (United States)

    Thomas, Piri

    1975-01-01

    The United States revolution of 1776 is said to lose validity in light of Puerto Rico's colonial situation under American rule. The plight of the Puerto Rican people is compared to that of the Euro-American settlers under the thumb-screw of British imperialism. (Author/AM)

  14. Medical management: from colony to community.

    Science.gov (United States)

    Aldenkamp, Albert P

    2010-12-01

    In this article the development from the colonies founded in the 19th century to the current situation is discussed. Future development is not to simply follow the slogan 'to the community' translated as 'epilepsy must be treated in general hospitals' but to preserve epileptology as specialized care with 'centres of excellence' orchestrated by coupling epilepsy centres with academical neurology. PMID:21074458

  15. Project Final Report: HPC-Colony II

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Terry R [ORNL; Kale, Laxmikant V [University of Illinois, Urbana-Champaign; Moreira, Jose [IBM T. J. Watson Research Center

    2013-11-01

    This report recounts the HPC Colony II Project which was a computer science effort funded by DOE's Advanced Scientific Computing Research office. The project included researchers from ORNL, IBM, and the University of Illinois at Urbana-Champaign. The topic of the effort was adaptive system software for extreme scale parallel machines. A description of findings is included.

  16. Latin America: Essays Interpretating Colonial Legacy

    Directory of Open Access Journals (Sweden)

    María Pia López

    2013-12-01

    Full Text Available A large part of the Latin–American literature of the 19th and 20th century tried to deal with the national question intertwining different dimensions: the weight of colonial legacy, the cultural peculiarity of the nation and the inner relations between social classes and ethnic groups. Thinking the nation implied, in any case, to think the difference and the conflict with others, as well as the inner conflict and the logic of local colonialism. Analyzing some of these essays that played a central role in such process of recasting the origin of the nation, the author moves around three main axes: the formulation of dualist writings (colonial/national; white /indigenous; civilization/wilderness, the issue of language (the language inherited from the colonial experience versus the multilingual nature of indigenous Latin American societies, and the hypothesis about the birth of the nation – appointed to different groups – and its normal functioning as legitimization of the order sprung from independences.

  17. How to measure inclusive fitness.

    Science.gov (United States)

    Creel, S

    1990-09-22

    Although inclusive fitness (Hamilton 1964) is regarded as the basic currency of natural selection, difficulty in applying inclusive fitness theory to field studies persists, a quarter-century after its introduction (Grafen 1982, 1984; Brown 1987). For instance, strict application of the original (and currently accepted) definition of inclusive fitness predicts that no one should ever attempt to breed among obligately cooperative breeders. Much of this confusion may have arisen because Hamilton's (1964) original verbal definition of inclusive fitness was not in complete accord with his justifying model. By re-examining Hamilton's original model, a modified verbal definition of inclusive fitness can be justified. PMID:1979447

  18. Preliminary catalog of seabird colonies and photographic mapping of seabird colonies: Annual report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This preliminary catalog identifies 339 seabird colonies lying along the North Pacific coast of Alaska between Cape Fairweather and Unimak Pass. Information is...

  19. Proud to be a Goan: colonial memories, post-colonial identities and music

    OpenAIRE

    Sardo, Susana

    2010-01-01

    During 451 years of colonial history, catholic Goans used music as a mediator of identity negotiation. In a political context repressing musical sonority of Indian flavour, in which Portuguese was the official language, catholic Goans created their own music, sung in Konkani and performed according to Portuguese models. Mandó among other hybrid and ambivalent musical genres, comprehen- sible for colonial rulers and Goans but with different significance for both, acquired an emblematic status....

  20. Ireland – a test case of Post-colonialism / Post colonialism

    Directory of Open Access Journals (Sweden)

    Brenda Murray

    2006-05-01

    Full Text Available Contextualisation This review attempts to set the stage for post-colonial theorising, in the light of alternative representations of ‘whiteness’, on issues of gender, race and language within the discourse of equality. In this paper Ireland and the Irish provide a backdrop against which the nature and impact of colonialism on the colonised and the coloniser are explored. Many challenging questions emerge about the ideological basis of post colonial theory, not least when traditional paradigms of racism, as conveyed by the black / white dichotomy, are examined: Ireland presents a context, it is argued, where subjugation is of white on white. Linked to this is the language of the coloniser, a powerful hegemonic force which, in some situations, has been nurtured by the colonised and later developed into a text which is unique, producing a new literature which, it is asserted, truly invokes the ‘post colonial’. Abstract: Post-colonialism – essentially a critique of colonialism, is characterised by a process of disengagement from the colonial epoch and has taken many forms. In this article a set of phenomena are examined that have become inscribed in the cultures of the colonised with a view to identifying alternative cultural origins and dispositions recovered in this post-colonial era. Ireland and the Irish provide the background context of this exploration into perspectives generated by the peripheral or post-colonial nations. Globalisation, too, has had a role to play in the increasing de-territorialisation of communities as a result of cross-frontier mobility, increased intra-community mobility and new communication technologies. A critical reflection on the process of disengagement leads the author to conclude that we must come to recognise new cultural forms which are accepting of a heterogeneous and inclusive society: one which is not characterised by difference.

  1. A quantitative model of honey bee colony population dynamics.

    Directory of Open Access Journals (Sweden)

    David S Khoury

    Full Text Available Since 2006 the rate of honey bee colony failure has increased significantly. As an aid to testing hypotheses for the causes of colony failure we have developed a compartment model of honey bee colony population dynamics to explore the impact of different death rates of forager bees on colony growth and development. The model predicts a critical threshold forager death rate beneath which colonies regulate a stable population size. If death rates are sustained higher than this threshold rapid population decline is predicted and colony failure is inevitable. The model also predicts that high forager death rates draw hive bees into the foraging population at much younger ages than normal, which acts to accelerate colony failure. The model suggests that colony failure can be understood in terms of observed principles of honey bee population dynamics, and provides a theoretical framework for experimental investigation of the problem.

  2. Sensitization of Parker fittings

    International Nuclear Information System (INIS)

    At your request, ferrules from 316 SS Parker-Hannifen compression fittings at the FFTF have been examined and evaluated to determine the metallurgical condition as related to carbide precipitation in grain boundaries (known as sensitization) and the implications this may have with regard to corrosion resistance. To accomplish this, two ferrules from new stock, two ferrules from old stock and two ferrules that had seen service were examined metallurgically. The samples were prepared for optical metallography. They were viewed in both the etched and unetched condition and analyzed on the scanning electron microscope (SEM) for elemental content. It was confirmed that the ferrules from new stock had a 5 mil thick nitrided layer on the ferrule ID at the lead end and that the 316 SS ferrule material was in the sensitized condition, indicating low resistance to aqueous corrosion. The material from old stock had no nitride layer but was in the sensitized condition indicating low resistance to aqueous corrosion. The ferrules that had seen service had not been nitrided and were not sensitized indicating high resistance to aqueous corrosion

  3. Fitness in fluctuating environments

    Science.gov (United States)

    Tanase Nicola, Sorin; Nemenman, Ilya

    2011-03-01

    Often environments change faster than the time needed to evolve optimal phenotypes through cycles of mutation and selection. We focus on this case, but assume that environmental oscillations are slower than an individual's lifetime. This is relevant, for example, for bacterial populations confronted with daily environmental changes. We analyze a resource-limited competition between a mutant phenotype and the ancestor. Environmental dynamics is represented by periodically varying, off-phase parameters of the corresponding Lotka-Volterra model. For the very slow dynamics (but still faster than the fixation time scale) the strength and the sign of selection are functions of the birth/death rates averaged over all of the environmental states and independent of the period of the fluctuations. For faster fluctuations, selection depends on the particular sequence of the successive environmental states. In particular, a time reversal of the environmental dynamics can change the sign of the selection. We conclude that the fittest phenotype in a changing environment can be very different from both the optimal phenotype in the average environment, and the phenotype with the largest average fitness.

  4. Optimized Ant Colony Algorithm by Local Pheromone Update

    OpenAIRE

    Hui Yu

    2013-01-01

    Ant colony algorithm, a heuristic simulated algorithm, provides better solutions for non-convex, non-linear and discontinuous optimization problems. For ant colony algorithm, it is frequently to be trapped into local optimum, which might lead to stagnation. This article presents the  city-select strategy, local pheromone update strategy, optimum solution prediction strategy and local optimization strategy to optimize ant colony algorithm, provides ant colony algorithm based on local pheromone...

  5. Brazilian Higher Education from a Post-Colonial Perspective

    Science.gov (United States)

    Leite, Denise

    2010-01-01

    This article examines Brazilian higher education (HE) politics from a post-colonial perspective. The term "post-colonial" originally referred to a historical period of colonial empires established by European nations. Nowadays, the term commonly distinguishes a field of contemporary studies of "defamiliarisation of the imperial North" made up of…

  6. Oversea Education and British Colonial Education 1929-63.

    Science.gov (United States)

    Whitehead, Clive

    2003-01-01

    Focuses on an early twentieth century journal called "Oversea Education," designed to increase communication among British colonies, particularly for education, based on William Ormsby Gore's travels among the colonies. Describes Frank Ward's editorial work that championed the rights of colonial subjects to have better educational policy. (KDR)

  7. Standard methods for estimating strength parameters of Apis mellifera colonies

    NARCIS (Netherlands)

    Delaplane, K.S.; Steen, van der J.J.M.; Guzman-Novoa, E.

    2013-01-01

    This paper covers measures of field colony strength, by which we mean population measures of adult bees and brood. There are generally two contexts in which an investigator wishes to measure colony strength: 1. at the beginning of a study as part of manipulations to produce uniform colonies and redu

  8. Deformed Wing Virus Implicated in Overwintering Honeybee Colony Losses ▿

    Science.gov (United States)

    Highfield, Andrea C.; El Nagar, Aliya; Mackinder, Luke C. M.; Noël, Laure M.-L. J.; Hall, Matthew J.; Martin, Stephen J.; Schroeder, Declan C.

    2009-01-01

    The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV), and black queen cell virus (BQCV), during a 1-year period in 15 asymptomatic, varroa mite-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be varroa mite free. All colonies with varroa mites underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet a significant correlation was observed only between DWV viral load and overwintering colony losses. The long-held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe varroa mite infestations. Our findings suggest that DWV can potentially act independently of varroa mites to bring about colony losses. Therefore, DWV may be a major factor in overwintering colony losses. PMID:19783750

  9. Deformed wing virus implicated in overwintering honeybee colony losses.

    Science.gov (United States)

    Highfield, Andrea C; El Nagar, Aliya; Mackinder, Luke C M; Noël, Laure M-L J; Hall, Matthew J; Martin, Stephen J; Schroeder, Declan C

    2009-11-01

    The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV), and black queen cell virus (BQCV), during a 1-year period in 15 asymptomatic, varroa mite-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be varroa mite free. All colonies with varroa mites underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet a significant correlation was observed only between DWV viral load and overwintering colony losses. The long-held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe varroa mite infestations. Our findings suggest that DWV can potentially act independently of varroa mites to bring about colony losses. Therefore, DWV may be a major factor in overwintering colony losses. PMID:19783750

  10. ACOustic: A Nature-Inspired Exploration Indicator for Ant Colony Optimization.

    Science.gov (United States)

    Sagban, Rafid; Ku-Mahamud, Ku Ruhana; Abu Bakar, Muhamad Shahbani

    2015-01-01

    A statistical machine learning indicator, ACOustic, is proposed to evaluate the exploration behavior in the iterations of ant colony optimization algorithms. This idea is inspired by the behavior of some parasites in their mimicry to the queens' acoustics of their ant hosts. The parasites' reaction results from their ability to indicate the state of penetration. The proposed indicator solves the problem of robustness that results from the difference of magnitudes in the distance's matrix, especially when combinatorial optimization problems with rugged fitness landscape are applied. The performance of the proposed indicator is evaluated against the existing indicators in six variants of ant colony optimization algorithms. Instances for travelling salesman problem and quadratic assignment problem are used in the experimental evaluation. The analytical results showed that the proposed indicator is more informative and more robust. PMID:25954768

  11. Fitness Landscapes of Functional RNAs

    Directory of Open Access Journals (Sweden)

    Ádám Kun

    2015-08-01

    Full Text Available The notion of fitness landscapes, a map between genotype and fitness, was proposed more than 80 years ago. For most of this time data was only available for a few alleles, and thus we had only a restricted view of the whole fitness landscape. Recently, advances in genetics and molecular biology allow a more detailed view of them. Here we review experimental and theoretical studies of fitness landscapes of functional RNAs, especially aptamers and ribozymes. We find that RNA structures can be divided into critical structures, connecting structures, neutral structures and forbidden structures. Such characterisation, coupled with theoretical sequence-to-structure predictions, allows us to construct the whole fitness landscape. Fitness landscapes then can be used to study evolution, and in our case the development of the RNA world.

  12. Studying Colonialism in Spanish History Textbooks

    DEFF Research Database (Denmark)

    Brescó, Ignacio

    2016-01-01

    The interwoven dynamics underpinning national identity and collective memory have received growing interest from different disciplines in light of an increasingly globalized and multicultural world. In this context, history textbooks play an important role inasmuch as the introduction of history in...... classrooms in the 19th Century has aimed at transmitting a shared past in order to encourage subjects to identify with their nation. In psychology different studies have focused on history textbooks as cultural tools for memory and identity, drawing attention to their role in conveying a social...... representation of the nation’s historical past. Along these lines, this paper aims to examine the representation of an especially controversial past, such as colonialism, in Spanish secondary history textbooks in two different periods, in late 70’-early 80’ (just after the loss of the last Spanish colonies in...

  13. Regulaciones de la vida urbana colonial

    Directory of Open Access Journals (Sweden)

    Jorge Núñez Sánchez

    2006-11-01

    Full Text Available Este ensayo analiza ciertas normas dictadas por la Corona con el propósito de regular la vida urbana a lo largo del período colonial. El artículo centra su estudio en algunas disposiciones que buscaban refrenar el desorden público y mantener el orden y las normas del "buen vivir". Bajo esta perspectiva, se analizan algunas prácticas culturales que se apartaban de estas regulaciones, entre las que se incluyeron los albazos y carnavales. Muchas de estas manifestaciones fueron percibidas por el poder colonial como muestras de primitivismo latente. No obstante, el juego de carnaval, entre otras prácticas, se mantuvo reacio a acatar estas regulaciones.

  14. African Economic Development and Colonial Legacies

    Directory of Open Access Journals (Sweden)

    Gareth Austin

    2010-03-01

    Full Text Available This article reviews how colonial rule and African actions during the colonial period affected the resources and institutional settings for subsequent economic development south of the Sahara. The issue is seen from the perspective of the dynamics of development in what was in 1900 an overwhelmingly land-abundant region characterised by shortages of labour and capital, by perhaps surprisingly extensive indigenous market activities and by varying but often low levels of political centralisation. The differential impact of French and British rule is explored, but it is argued that a bigger determinant of the differential evolution of poverty, welfare and structural change was the contrast between “settler” and “peasant” economies.

  15. 1848, des colonies et l'histoire

    OpenAIRE

    Schmidt, Nelly

    2008-01-01

    Comment évoluèrent depuis 1948 la lecture et l'interprétation de la Seconde République dans les colonies, période courte mais souvent déterminante de leur histoire ? Le Centenaire a été celui de la célébration du " culte schoelcherien ", en même temps que débutait la départementalisation des colonies de Guadeloupe, Guyane, Martinique et Réunion. Les années 1960-1970 ont vu naître un courant historiographique s'élevant contre un discours historique réducteur, remettant en cause les cloisonneme...

  16. Post-colonial identity in Greenland?

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2009-01-01

    In the gradual unravelling of Greenland’s colonial relationship to Denmark, an essentialist conceptualization of Greenlandic identity has played a significant role. However, both our scholarly understanding of post-colonial Greenlandic identity and the process towards independence for Greenland c...... exclusion of valuable human resources. One step towards relieving the relation to the Danish Other of identificatory weight could be a gradual shift to English as second language. [ABSTRACT FROM AUTHOR]...... could be furthered by bringing politics back in. Based on a discourse analysis of the Greenlandic debate on language, this paper makes three claims: First, the identity projects promoted in Greenland are based on an essentialist conception of identity. Secondly, Greenlandic identity discourse combines...

  17. Reeling of tight fit pipe

    OpenAIRE

    Focke, E.S.

    2007-01-01

    If it would be possible to install Tight Fit Pipe by means of reeling, it would be an attractive new option for the exploitation of offshore oil and gas fields containing corrosive hydrocarbons. Tight Fit Pipe is a mechanically bonded double walled pipe where a corrosion resistant alloy liner pipe is mechanically fitted inside a carbon steel outer pipe through a thermo-hydraulic manufacturing process. Reeling is a fast method of offshore pipeline installation where a pipe is spooled on a reel...

  18. Influence of feeding bee colonies on colony strenght and honey authenticity

    Directory of Open Access Journals (Sweden)

    Andreja KANDOLF BOROVŠAK

    2015-12-01

    Full Text Available For the natural development of bee colonies, there is the need for appropriate nutrition. Lack of natural honey flow must be supplemented by feeding bee colonies with sugar syrups or candy paste. This supplementary feeding encourages brood breeding and forage activity, whereby stronger colonies collect more honey. Sugar syrups can cause honey adulteration, which is more frequent with the reversing of the brood combs with the bee food, with the combs moved from the brood chamber to the upper chamber. Authentication of honey from the standpoint of the presence of sugar syrup is very complex, because there is no single method by which honey adulteration can be reliably confirmed. Feeding the colonies in spring should result in stronger colonies and hence the collection of more honey in the brood chambers. The objective of the present study was to determine whether this has effects also on honey authenticity, and to discover a simple method for detection of honey adulteration. The colonies were fed with candy paste that had added yeast and blue dye, to provide markers for detection of honey adulteration. The strength of the colonies and quantity of honey in the brood chambers were monitored. The results of the analysis of stable isotope and activity of foreign enzymes were compared with the results of yeast quantity and colour of the honey (absorbance, L*, a*, b* parameters. Detection of yeast in the honey samples and presence of colour as a consequence of added dye appear to be appropriate methods to follow honey adulteration, and further studies are ongoing.

  19. From Colonial Administration to Development Management

    OpenAIRE

    Cooke, Bill

    2001-01-01

    This paper is about the field of development management (previously development administration) and its continuities with the processes of imperial rule known as colonial administration. Development administration/ management represents itself as a subset of public administration/ public sector management. However, this conceals its status as First World discourse about how the Third World should be managed. Moreover, while development management recognizes the continuity between itself and p...

  20. Polyethism in a colony of artificial ants

    CERN Document Server

    Marriott, Chris

    2011-01-01

    We explore self-organizing strategies for role assignment in a foraging task carried out by a colony of artificial agents. Our strategies are inspired by various mechanisms of division of labor (polyethism) observed in eusocial insects like ants, termites, or bees. Specifically we instantiate models of caste polyethism and age or temporal polyethism to evaluated the benefits to foraging in a dynamic environment. Our experiment is directly related to the exploration/exploitation trade of in machine learning.

  1. Colonial Subjectification: Foucault, Christianity and Governmentality

    OpenAIRE

    Christina Petterson

    2012-01-01

    Foucault’s concept of pastoral power is envisioned as a technique of power developed from the medieval period and carried through into modern political rationalities. As such, it is an old power technique – which originated in Christian institutions – in a new political shape, which he coined governmentality. This article uses Foucault’s genealogy of pastoral power and governmentality to discuss the intersection of domination and technology of self in the Greenlandic colonial context and to b...

  2. Colonial and Cellular Polymorphism in Xenorhabdus luminescens

    OpenAIRE

    Hurlbert, Ronald E.; Xu, Jimin; SMALL, CHRISTOPHER L.

    1989-01-01

    A highly polymorphic Xenorhabdus luminescens strain was isolated. The primary form of X. luminescens was luminescent and nonswarming and produced a yellow pigment and antimicrobial substances. The primary form generated a secondary form that had a distinct orange pigmentation, was weakly luminescent, and did not produce antimicrobial substances. Both the primary and secondary forms generated a set of colony variants at frequencies that exceeded normal rates for spontaneous mutation. The varia...

  3. Optic disc detection using ant colony optimization

    OpenAIRE

    Dias, Marcy; Monteiro, Fernando C.

    2012-01-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detectio...

  4. Ant colony optimization and constraint programming

    CERN Document Server

    Solnon, Christine

    2013-01-01

    Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

  5. Eutectic Colony Formation: A Stability Analysis

    OpenAIRE

    Plapp, Mathis; Karma, Alain

    1998-01-01

    Experiments have widely shown that a steady-state lamellar eutectic solidification front is destabilized on a scale much larger than the lamellar spacing by the rejection of a dilute ternary impurity and forms two-phase cells commonly referred to as `eutectic colonies'. We extend the stability analysis of Datye and Langer for a binary eutectic to include the effect of a ternary impurity. We find that the expressions for the critical onset velocity and morphological instability wavelength are ...

  6. Teamwork in Self-Organized Robot Colonies

    OpenAIRE

    Nouyan, Shervin; Groß, Roderich; Bonani, Michael; Mondada, F.; Dorigo, Marco

    2009-01-01

    Swarm robotics draws inspiration from decentralized self-organizing biological systems in general and from the collective behavior of social insects in particular. In social insect colonies, many tasks are performed by higher order group or team entities, whose task-solving capacities transcend those of the individual participants. In this paper, we investigate the emergence of such higher order entities. We report on an experimental study in which a team of physical robots performs a foragin...

  7. Moving the Maasai: A Colonial Misadventure

    OpenAIRE

    Hughes, Lotte.

    2006-01-01

    The history of the Maasai moves, land alienation and resistance in colonial British East Africa. In 1904, in order to make way for white settlers in what was to become Kenya, the Maasai were forcibly moved into two reserves, robbing them of the best part of their land in British East Africa. Using unique oral testimony and archival evidence, this book tells the true story behind the making of the 'White Highlands', and the repercussions of these events to the present day.

  8. FITS Foreign File Encapsulation Convention

    CERN Document Server

    Zarate, Nelson; Tody, Doug

    2012-01-01

    This document describes a FITS convention developed by the IRAF Group (D. Tody, R. Seaman, and N. Zarate) at the National Optical Astronomical Observatory (NOAO). This convention is implemented by the fgread/fgwrite tasks in the IRAF fitsutil package. It was first used in May 1999 to encapsulate preview PNG-format graphics files into FITS files in the NOAO High Performance Pipeline System. A FITS extension of type 'FOREIGN' provides a mechanism for storing an arbitrary file or tree of files in FITS, allowing it to be restored to disk at a later time.

  9. VPFIT: Voigt profile fitting program

    Science.gov (United States)

    Carswell, R. F.; Webb, J. K.

    2014-08-01

    The VPFIT program fits multiple Voigt profiles (convolved with the instrument profiles) to spectroscopic data that is in FITS or an ASCII file. It requires CFITSIO (ascl:1010.001) and PGPLOT (ascl:1103.002); the tarball includes RDGEN (ascl:1408.017), which can be used with VPFIT to set up the fits, fit the profiles, and examine the result in interactive mode for setting up initial guesses; vpguess (ascl:1408.016) can also be used to set up an initial file.

  10. Swarming Ring Patterns in Bacterial Colonies Exposed to Ultraviolet Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Delprato, Anna M.; Samadani, Azadeh; Kudrolli, A.; Tsimring, L. S.

    2001-10-08

    We report a novel morphological transition in a Bacillus subtilis colony initially growing under ambient conditions, after ultraviolet radiation exposure. The bacteria in the central regions of the colonies are observed to migrate towards the colony edge forming a ring during uniform spatial exposure. When the radiation is switched off, the colonies were observed to grow both inward into the evacuated regions as well as outward indicating that the pattern is not formed due to depletion of nutrients at the center of the colony. We also propose a reaction-diffusion model in which waste-limited chemotaxis initiated by the UV radiation leads to the observed phenomenology.

  11. Honey bee colonies that have survived Varroa destructor

    OpenAIRE

    Le Conte, Yves; de Vaublanc, Gérard; Crauser, Didier; Jeanne, François; Rousselle, Jean-Claude; Bécard, Jean-Marc

    2007-01-01

    We document the ability of a population of honey bee colonies to survive in France without Varroa suppression measures. We compared the mortality of collected Varroa surviving bee (VSB) stock with that of miticide-treated Varroa-susceptible colonies. Varroa infestation did not induce mortality in the VSB colonies. Some of the original colonies survived more than 11 years without treatment and the average survival of the experimental colonies was 6.54 ± 0.25 years. Swarming was variable (41.50...

  12. Morphological Diversity of the Colony Produced by Bacteria Proteus mirabilis

    Science.gov (United States)

    Nakahara, Akio; Shimada, Yuji; Wakita, Jun-ichi; Matsushita, Mitsugu; Matsuyama, Tohey

    1996-08-01

    Morphological changes of colonies have been investigatedfor a bacterial strain of Proteus mirabilis, which is a famous speciesfor producing concentric-ring-like colonies. It was found that colony patterns can be classified into three types,i.e., cyclic spreading, diffusion-limited growth (DLA-like)and three-dimensional growth (inside the agar medium) patterns. Cyclic spreading patterns can further be classifiedinto three subgroups, i.e., concentric-ring, homogeneous and spatiotemporal patterns. These subgroups were classified by examining the development of colony structure after colonies spread all over petri-dishes. Comparison of the results with thoseof another bacterial species Bacillus subtilis is also discussed.

  13. Varroa-Virus Interaction in Collapsing Honey Bee Colonies

    DEFF Research Database (Denmark)

    Francis, Roy Mathew; Nielsen, Steen L.; Kryger, Per

    2013-01-01

    honey bees and varroa mites from 23 colonies (15 apiaries) under three treatment conditions: Organic acids (11 colonies), pyrethroid (9 colonies) and untreated (3 colonies). Approximately 200 bees were sampled every month from April 2011 to October 2011, and April 2012. The 200 bees were split to 10......Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI) and Deformed Wing Virus (DWV)) were monitored in a year-long study. We investigated the viral titres in...... subsamples of 20 bees and analysed separately, which allows us to determine the prevalence of virus-infected bees. The treatment efficacy was often low for both treatments. In colonies where varroa treatment reduced the mite load, colonies overwintered successfully, allowing the mites and viruses to be...

  14. Undifferentiated spleen colonies: an attempt to induce differentiation into eosinophils

    International Nuclear Information System (INIS)

    Repeated injections of casein caused a 4-fold increase in the overall number of colonies in the spleens of sublethally irradiated, polycythemic mice. Chronic (12 injections) casein treatment considerably increased the number of eosinophil and of undifferentiated colonies, but not that of granuloid ones. A reduction in number and size of eosinophil colonies took place between the sixth and the ninth day after irradiation. No such reduction occurred with undifferentiated colonies. Stimulation with casein for only 3 (consecutive) days before irradiation caused a similar increase in eosinophil colonies, only a moderate increase in undifferentiated ones and a very marked increase in granuloid colonies. Evidence for a change of undifferentiated colonies into eosinophil ones under conditions of eosinopoiesis was looked for, but not detected. No correlation was found between the amyloid-inducing capacity of caseins and their eosinopoietic potency

  15. Pollen foraging in colonies of Melipona bicolor (Apidae, Meliponini): effects of season, colony size and queen number.

    Science.gov (United States)

    Hilário, S D; Imperatriz-Fonseca, V L

    2009-01-01

    We evaluated the ratio between the number of pollen foragers and the total number of bees entering colonies of Melipona bicolor, a facultative polygynous species of stingless bees. The variables considered in our analysis were: seasonality, colony size and the number of physogastric queens in each colony. The pollen forager ratios varied significantly between seasons; the ratio was higher in winter than in summer. However, colony size and number of queens per colony had no significant effect. We conclude that seasonal differences in pollen harvest are related to the production of sexuals and to the number of individuals and their body size. PMID:19554765

  16. Reeling of tight fit pipe

    NARCIS (Netherlands)

    Focke, E.S.

    2007-01-01

    If it would be possible to install Tight Fit Pipe by means of reeling, it would be an attractive new option for the exploitation of offshore oil and gas fields containing corrosive hydrocarbons. Tight Fit Pipe is a mechanically bonded double walled pipe where a corrosion resistant alloy liner pipe i

  17. My Career: Group Fitness Instructor

    Science.gov (United States)

    Green, Kathleen

    2013-01-01

    This article presents an interview with Tammy Kenney, who teaches a yoga-Pilates class in several different gyms. In this interview, Kenney talks about her career as a group fitness instructor and gives her best advice for someone who wants to teach group fitness.

  18. Fitness Doping and Body Management

    DEFF Research Database (Denmark)

    Thualagant, Nicole

    This PhD thesis examines in a first paper the conceptualization of fitness doping and its current limitations. Based on a review of studies on bodywork and fitness doping it is emphasised that the definition of doping does not provide insights into bodywork of both men and women. Moreover, it is...... argued that the social and a cultural context are missing in the many epidemiological studies on the prevalence of doping. The second paper explores the difficulties of implementing an anti-doping policy, which was originally formulated in an elite sport context, in a fitness context and more......-based fitness centres. Based on a survey in ten Danish club-based fitness centres and on narratives from semi-structured interviews, it is highlighted that the objectives of bodywork differ according to the users’ age and gender. Two different ways of investing in the body are explored in the paper, namely a...

  19. Using Ant Colony Optimization for Routing in VLSI Chips

    Science.gov (United States)

    Arora, Tamanna; Moses, Melanie

    2009-04-01

    Rapid advances in VLSI technology have increased the number of transistors that fit on a single chip to about two billion. A frequent problem in the design of such high performance and high density VLSI layouts is that of routing wires that connect such large numbers of components. Most wire-routing problems are computationally hard. The quality of any routing algorithm is judged by the extent to which it satisfies routing constraints and design objectives. Some of the broader design objectives include minimizing total routed wire length, and minimizing total capacitance induced in the chip, both of which serve to minimize power consumed by the chip. Ant Colony Optimization algorithms (ACO) provide a multi-agent framework for combinatorial optimization by combining memory, stochastic decision and strategies of collective and distributed learning by ant-like agents. This paper applies ACO to the NP-hard problem of finding optimal routes for interconnect routing on VLSI chips. The constraints on interconnect routing are used by ants as heuristics which guide their search process. We found that ACO algorithms were able to successfully incorporate multiple constraints and route interconnects on suite of benchmark chips. On an average, the algorithm routed with total wire length 5.5% less than other established routing algorithms.

  20. Loading pattern optimization of PWR reactors using Artificial Bee Colony

    International Nuclear Information System (INIS)

    Highlights: → ABC algorithm is comparable to the canonical GA algorithm and PSO. → The performance of ABC shows that the algorithm is quiet promising. → The final band width of search fitness values by ABC is narrow. → The ABC algorithm is relatively easy to implement. - Abstract: In this paper a core reloading technique using Artificial Bee Colony algorithm, ABC, is presented in the context of finding an optimal configuration of fuel assemblies. The proposed method can be used for in-core fuel management optimization problems in pressurized water reactors. To evaluate the proposed technique, the power flattening of a VVER-1000 core is considered as an objective function although other variables such as Keff, power peaking factor, burn up and cycle length can also be taken into account. The proposed optimization method is applied to a core design optimization problem previously solved with Genetic and Particle Swarm Intelligence Algorithm. The results, convergence rate and reliability of the new method are quite promising and show that the ABC algorithm performs very well and is comparable to the canonical Genetic Algorithm and Particle Swarm Intelligence, hence demonstrating its potential for other optimization applications in nuclear engineering field as, for instance, the cascade problems.

  1. CFAssay: statistical analysis of the colony formation assay

    International Nuclear Information System (INIS)

    Colony formation assay is the gold standard to determine cell reproductive death after treatment with ionizing radiation, applied for different cell lines or in combination with other treatment modalities. Associated linear-quadratic cell survival curves can be calculated with different methods. For easy code exchange and methodological standardisation among collaborating laboratories a software package CFAssay for R (R Core Team, R: A Language and Environment for Statistical Computing, 2014) was established to perform thorough statistical analysis of linear-quadratic cell survival curves after treatment with ionizing radiation and of two-way designs of experiments with chemical treatments only. CFAssay offers maximum likelihood and related methods by default and the least squares or weighted least squares method can be optionally chosen. A test for comparision of cell survival curves and an ANOVA test for experimental two-way designs are provided. For the two presented examples estimated parameters do not differ much between maximum-likelihood and least squares. However the dispersion parameter of the quasi-likelihood method is much more sensitive for statistical variation in the data than the multiple R2 coefficient of determination from the least squares method. The dispersion parameter for goodness of fit and different plot functions in CFAssay help to evaluate experimental data quality. As open source software interlaboratory code sharing between users is facilitated

  2. Parallelization Strategies for Ant Colony Optimisation on GPUs

    CERN Document Server

    Cecilia, Jose M; Ujaldon, Manuel; Nisbet, Andy; Amos, Martyn

    2011-01-01

    Ant Colony Optimisation (ACO) is an effective population-based meta-heuristic for the solution of a wide variety of problems. As a population-based algorithm, its computation is intrinsically massively parallel, and it is there- fore theoretically well-suited for implementation on Graphics Processing Units (GPUs). The ACO algorithm comprises two main stages: Tour construction and Pheromone update. The former has been previously implemented on the GPU, using a task-based parallelism approach. However, up until now, the latter has always been implemented on the CPU. In this paper, we discuss several parallelisation strategies for both stages of the ACO algorithm on the GPU. We propose an alternative data-based parallelism scheme for Tour construction, which fits better on the GPU architecture. We also describe novel GPU programming strategies for the Pheromone update stage. Our results show a total speed-up exceeding 28x for the Tour construction stage, and 20x for Pheromone update, and suggest that ACO is a po...

  3. ENHANCEMENT AND COMPARISON OF ANT COLONY OPTIMIZATION FOR SOFTWARE RELIABILITY MODELS

    Directory of Open Access Journals (Sweden)

    Latha Shanmugam

    2013-01-01

    Full Text Available In Common parlance, the traditional software reliability estimation methods often rely on assumptions like statistical distributions that are often dubious and unrealistic. The ability to predict the number of faults during development phase and a proper testing process helps in specifying timely release of software and efficient management of project resources. In the Present Study Enhancement and Comparison of Ant Colony Optimization Methods for Software Reliability Models are studied and the estimation accuracy was calculated. The Enhanced method shows significant advantages in finding the goodness of fit for software reliability model such as finite and infinite failure Poisson model and binomial models.

  4. Ant Colony Algorithm and Optimization of Test Conditions in Analytical Chemistry

    Institute of Scientific and Technical Information of China (English)

    丁亚平; 吴庆生; 苏庆德

    2003-01-01

    The research for the new algorithm is in the forward position and an issue of general interest in chemometrics all along.A novel chemometrics method,Chemical Ant Colony Algorithm,has first been developed.In this paper,the basic principle,theevaluation function,and the parameter choice were discussed.This method has been successfully applied to the fitting of nonlinear multivariate function and the optimization of test conditions in chrome-azure-S-Al spctrophotometric system.The sum of residual square of the results is 0.0009,which has reached a good convergence result.

  5. Effect of fluid motion on colony formation in Microcystis aeruginosa

    Directory of Open Access Journals (Sweden)

    Lin LI

    2013-01-01

    Full Text Available Microcystis aeruginosa, generally occurring in large colonies under natural conditions, mainly exists as single cells in laboratory cultures. The mechanisms involved in colony formation in Microcystis aeruginosa and their roles in algal blooms remain unknown. In this study, based on previous research findings that fluid motion may stimulate the colony formation in green algae, culture experiments were conducted under axenic conditions in a circular water chamber where the flow rate, temperature, light, and nutrients were controlled. The number of cells of Microcystis aeruginosa, the number of cells per colony, and the colonial characteristics in various growth phases were observed and measured. The results indicated that the colony formation in Microcystis aeruginosa, which was not observed under stagnant conditions, was evident when there was fluid motion, with the number of cells per largest colony reaching 120 and the proportion of the number of cells in colonial form to the total number of cells and the mean number of cells per colony reaching their peak values at a flow rate of 35 cm/s. Based on the analysis of colony formation process, fluid motion stimulates the colony formation in Microcystis aeruginosa in the lag growth phase, while flushes and disaggregates the colonies in the exponential growth phase. The stimulation effect in the lag growth phase may be attributable to the involvement of fluid motion in a series of physiological processes, including the uptake of trace elements and the synthesis and secretion of polysaccharides. In addition, the experimental groups exhibiting typical colonial characteristics in the lag growth phase were found to have higher cell biomass in the later phase.

  6. Colonial Subjectification: Foucault, Christianity and Governmentality

    Directory of Open Access Journals (Sweden)

    Christina Petterson

    2012-09-01

    Full Text Available Foucault’s concept of pastoral power is envisioned as a technique of power developed from the medieval period and carried through into modern political rationalities. As such, it is an old power technique – which originated in Christian institutions – in a new political shape, which he coined governmentality. This article uses Foucault’s genealogy of pastoral power and governmentality to discuss the intersection of domination and technology of self in the Greenlandic colonial context and to bring out the central role of religion in Foucault’s conceptualisation of governmentality.

  7. Intercellular Genomics of Subsurface Microbial Colonies

    Energy Technology Data Exchange (ETDEWEB)

    Ortoleva, Peter; Tuncay, Kagan; Gannon, Dennis; Meile, Christof

    2007-02-14

    This report summarizes progress in the second year of this project. The objective is to develop methods and software to predict the spatial configuration, properties and temporal evolution of microbial colonies in the subsurface. To accomplish this, we integrate models of intracellular processes, cell-host medium exchange and reaction-transport dynamics on the colony scale. At the conclusion of the project, we aim to have the foundations of a predictive mathematical model and software that captures the three scales of these systems – the intracellular, pore, and colony wide spatial scales. In the second year of the project, we refined our transcriptional regulatory network discovery (TRND) approach that utilizes gene expression data along with phylogenic similarity and gene ontology analyses and applied it successfully to E.coli, human B cells, and Geobacter sulfurreducens. We have developed a new Web interface, GeoGen, which is tailored to the reconstruction of microbial TRNs and solely focuses on Geobacter as one of DOE’s high priority microbes. Our developments are designed such that the frameworks for the TRND and GeoGen can readily be used for other microbes of interest to the DOE. In the context of modeling a single bacterium, we are actively pursuing both steady-state and kinetic approaches. The steady-state approach is based on a flux balance that uses maximizing biomass growth rate as its objective, subjected to various biochemical constraints, for the optimal values of reaction rates and uptake/release of metabolites. For the kinetic approach, we use Karyote, a rigorous cell model developed by us for an earlier DOE grant and the DARPA BioSPICE Project. We are also investigating the interplay between bacterial colonies and environment at both pore and macroscopic scales. The pore scale models use detailed representations for realistic porous media accounting for the distribution of grain size whereas the macroscopic models employ the Darcy-type flow

  8. Josephine Baker: psychoanalysis and the colonial fetish.

    Science.gov (United States)

    Cheng, Anne Anlin

    2006-01-01

    This paper traces an intricate path connecting racial fantasy, aesthetic judgment, and the larger cultural problem of inter-subjective recognition. In particular, the author examines the theme of fetishism, both sexual and racial, in a Western historical, colonial context, in order to unravel a set of disturbances that cohere around the racial fetish then and now. Taking the figure of an entertainment icon of the 1920s, Josephine Baker, as a case study, the author shows how the imagination of the colonizing white male was both articulated and disrupted by Baker as a ready-made representation of the cultural, racial, and sexual other. PMID:16482962

  9. Spatiotemporal evolution of bacterial biofilm colonies

    Science.gov (United States)

    Wilking, James; Koehler, Stephan; Sinha, Naveen; Seminara, Agnese; Brenner, Michael; Weitz, David

    2014-03-01

    Many bacteria on earth live in surface-attached communities known as biofilms. Gene expression in a biofilm is typically varied, resulting in a variety of phenotypes within a single film. These phenotypes play a critical role in biofilm physiology and development. We use time-resolved, wide-field fluorescence microscopy to image triple-labeled fluorescent Bacillus Subtilis colonies grown on agar to determine in a non-invasive fashion the evolving phenotypes. We infer their transition rates from the resulting spatiotemporal maps of gene expression. Moreover, we correlate these transition rates with local measurements of nutrient concentration to determine the influence of extracellular signals on gene expression.

  10. Enhanced ant colony optimization for multiscale problems

    Science.gov (United States)

    Hu, Nan; Fish, Jacob

    2016-03-01

    The present manuscript addresses the issue of computational complexity of optimizing nonlinear composite materials and structures at multiple scales. Several solutions are detailed to meet the enormous computational challenge of optimizing nonlinear structures at multiple scales including: (i) enhanced sampling procedure that provides superior performance of the well-known ant colony optimization algorithm, (ii) a mapping-based meshing of a representative volume element that unlike unstructured meshing permits sensitivity analysis on coarse meshes, and (iii) a multilevel optimization procedure that takes advantage of possible weak coupling of certain scales. We demonstrate the proposed optimization procedure on elastic and inelastic laminated plates involving three scales.

  11. Combined Final Report for Colony II Project

    Energy Technology Data Exchange (ETDEWEB)

    Kale, Laxmikant [University of Illinois; Jones, Terry [Oak Ridge National Laboratory; Moreira, Jose [IBM Corp.

    2013-10-23

    (This report was originally submmited by the lead PI (Terry Jones, ORNL) on October 22, 2013 to the program manager, Lucy Nowell. It is being submitted from University of Illinois in accordance with instructions). HPC Colony II seeks to provide portable performance for leadership class machines. Our strategy is based on adaptive system software that aims to make the intelligent decisions necessary to allow domain scientists to safely focus on their task at hand and allow the system software stack to adapt their application to the underlying architecture. This report describes the research undertaken towards these objectives and the results obtained over the performance period of the project.

  12. Mamary neoplasia in a closed beagle colony

    International Nuclear Information System (INIS)

    The incidence rate of mammary neoplasia in a large colony of beagles and its relationship to internal skeletal and/or liver radiation, age, relatively late ovariectomy (4 years and older), endometritis, parity status, and adrenal weight was examined. Of these various factors, age was the only condition that was clearly correlated with changes in the mammary tumor incidence. The rate became significant at approximately eight years of age and increased progressively throughout the successively older age classes. Within the female dogs, the incidence of mammary cancer was higher that that of any other form of spontaneous malignancy

  13. Malaria, Colonial Economics and Migrations in Vietnam

    OpenAIRE

    Guénel, Annick

    2004-01-01

    This paper will explore the evolution of the colonial views on the connection between malaria and environment in Vietnam, notably in relation to the different populations who live there. The colonization of Vietnam by the French introduced a major shift: the change of migration direction. From the 14th century on, the “Viêt” or “Kinh”, the major ethnic group in Vietnam, originally concentrated in the Red River delta, migrated to the south to colonize new lowlands, where they could reproduce t...

  14. Opas CrossFit -harjoitteluun

    OpenAIRE

    Knaapi, Matti

    2014-01-01

    CrossFit on laji, joka pyrkii edistämään terveyttä ja kuntoa. CrossFit saleja löytyy mailmalta yli 10 000 kappaletta. CrossFit -harjoittelussa pyritään parantamaan ihmisen kuntoa mahdollisimman laajalla skaalalla kehittämällä mm. voimaa, kestävyyttä, tarkkuutta, tasapainoa ja eri aineenvaihduntareittejä samanaikaisesti. Terveyden ja kunnon kehittämiseen kuuluu kuntoilun lisäksi myös muita osa-alueita. Ruokavalio ja kehonhuolto ovat tärkeitä osa-alueita hyvän kunnon saavuttamiseksi. Ruokav...

  15. FITS Foreign File Encapsulation Convention

    OpenAIRE

    Zarate, Nelson; Seaman, Rob; Tody, Doug

    2012-01-01

    This document describes a FITS convention developed by the IRAF Group (D. Tody, R. Seaman, and N. Zarate) at the National Optical Astronomical Observatory (NOAO). This convention is implemented by the fgread/fgwrite tasks in the IRAF fitsutil package. It was first used in May 1999 to encapsulate preview PNG-format graphics files into FITS files in the NOAO High Performance Pipeline System. A FITS extension of type 'FOREIGN' provides a mechanism for storing an arbitrary file or tree of files i...

  16. ALFA: Automated Line Fitting Algorithm

    Science.gov (United States)

    Wesson, R.

    2015-12-01

    ALFA fits emission line spectra of arbitrary wavelength coverage and resolution, fully automatically. It uses a catalog of lines which may be present to construct synthetic spectra, the parameters of which are then optimized by means of a genetic algorithm. Uncertainties are estimated using the noise structure of the residuals. An emission line spectrum containing several hundred lines can be fitted in a few seconds using a single processor of a typical contemporary desktop or laptop PC. Data cubes in FITS format can be analysed using multiple processors, and an analysis of tens of thousands of deep spectra obtained with instruments such as MUSE will take a few hours.

  17. Bumblebees Learn Polarization Patterns

    OpenAIRE

    Foster, James J.; Sharkey, Camilla R.; Gaworska, Alicia V.A.; Roberts, Nicholas W.; Whitney, Heather M.; Partridge, Julian C.

    2014-01-01

    Summary Foraging insect pollinators such as bees must find and identify flowers in a complex visual environment. Bees use skylight polarization patterns for navigation [1–3], a capacity mediated by the polarization-sensitive dorsal rim area (DRA) of their eye [4, 5]. While other insects use polarization sensitivity to identify appropriate habitats [6], oviposition sites, and food sources [7], to date no nonnavigational functions of polarization vision have been identified in bees. Here we inv...

  18. Stable isotope enrichment in laboratory ant colonies: effects of colony age, metamorphosis, diet, and fat storage

    Science.gov (United States)

    Ecologists use stable isotopes to infer diets and trophic levels of animals in food webs, yet some assumptions underlying these inferences have not been thoroughly tested. We used laboratory-reared colonies of Solenopsis invicta Buren (Formicidae: Solenopsidini) to test the effects of metamorphosis,...

  19. Kinematic Fitting of Detached Vertices

    Energy Technology Data Exchange (ETDEWEB)

    Paul Mattione

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  20. Colonial connections and consulting engineers 1850-1914

    DEFF Research Database (Denmark)

    Andersen, Casper

    2011-01-01

    The paper analyses colonial connections and networks of British consulting engineers. It unravels how consulting engineers operated within different imperial contexts, including settler colonies, Egypt and Crown colonies in West Africa in particular. The paper also examines the close and at times...... strained connections that existed between London's consulting engineers and British engineers stationed overseas in colonial public works departments. By examining the colonial connections of metropolitan engineers, the paper sheds light on a hitherto ignored factor that tied Britain and the colonies...... together during the diaspora of British engineering. It argues that personal connections and relations remained of paramount importance during this period, which has traditionally been described as characterised by growing professionalisation and a subsequent loss of the personal element in British...

  1. Image feature extraction based multiple ant colonies cooperation

    Science.gov (United States)

    Zhang, Zhilong; Yang, Weiping; Li, Jicheng

    2015-05-01

    This paper presents a novel image feature extraction algorithm based on multiple ant colonies cooperation. Firstly, a low resolution version of the input image is created using Gaussian pyramid algorithm, and two ant colonies are spread on the source image and low resolution image respectively. The ant colony on the low resolution image uses phase congruency as its inspiration information, while the ant colony on the source image uses gradient magnitude as its inspiration information. These two ant colonies cooperate to extract salient image features through sharing a same pheromone matrix. After the optimization process, image features are detected based on thresholding the pheromone matrix. Since gradient magnitude and phase congruency of the input image are used as inspiration information of the ant colonies, our algorithm shows higher intelligence and is capable of acquiring more complete and meaningful image features than other simpler edge detectors.

  2. Can cuticular lipids provide sufficient information for within-colony nepotism in wasps?

    Science.gov (United States)

    Dani, Francesca R; Foster, Kevin R; Zacchi, Francesca; Seppä, Perttu; Massolo, Alessandro; Carelli, Annalisa; Arévalo, Elisabeth; Queller, David C; Strassmann, Joan E; Turillazzi, Stefano

    2004-04-01

    Inclusive fitness theory predicts that members of non-clonal societies will gain by directing altruistic acts towards their closest relatives. Multiple mating by queens and multiple queens creates distinct full-sister groups in many hymenopteran societies within which nepotism might occur. However, the weight of empirical data suggests that nepotism within full-sister groups is absent. It has been suggested that a lack of reliable recognition markers is responsible. In this paper, we investigated whether epicuticular lipids could provide reliable cues for intracolony kin recognition in two species of social wasps, the paper wasp Polistes dominulus and the hornet Vespa crabro. Epicuticular lipids have previously been shown to be central to kin recognition at the nest level, making them excellent candidates for within-nest discrimination. We genotyped individuals using DNA microsatellites and analysed surface chemistry by gas chromatography-mass spectrometry. We find that in both species epicuticular lipids typically could provide enough information to distinguish related nest-mates from unrelated nest-mates, a difference that occurs in colonies with multiple queens. However, in V. crabro, where colonies may be composed by different patrilines, information for discrimination between full sisters and half-sisters is weaker and prone to errors. Our data suggest that epicuticular lipids at best provide reliable information for intracolony nepotistic discrimination in multiple-queen colonies composed of unrelated lines. PMID:15209109

  3. Statistical topography of fitness landscapes

    OpenAIRE

    Franke, Jasper

    2011-01-01

    Fitness landscapes are generalized energy landscapes that play an important conceptual role in evolutionary biology. These landscapes provide a relation between the genetic configuration of an organism and that organism’s adaptive properties. In this work, global topographical features of these fitness landscapes are investigated using theoretical models. The resulting predictions are compared to empirical landscapes. It is shown that these landscapes allow, at least with respe...

  4. Model fit and model selection

    OpenAIRE

    Kocherlakota, Narayana R.

    2007-01-01

    This paper uses an example to show that a model that fits the available data perfectly may provide worse answers to policy questions than an alternative, imperfectly fitting model. The author argues that, in the context of Bayesian estimation, this result can be interpreted as being due to the use of an inappropriate prior over the parameters of shock processes. He urges the use of priors that are obtained from explicit auxiliary information, not from the desire to obtain identification.

  5. Fitting and Interpreting Occupancy Models

    OpenAIRE

    Welsh, Alan H.; Lindenmayer, David B; Donnelly, Christine F.

    2013-01-01

    We show that occupancy models are more difficult to fit than is generally appreciated because the estimating equations often have multiple solutions, including boundary estimates which produce fitted probabilities of zero or one. The estimates are unstable when the data are sparse, making them difficult to interpret, and, even in ideal situations, highly variable. As a consequence, making accurate inference is difficult. When abundance varies over sites (which is the general rule in ecology b...

  6. Independence and trade: new evidence from French colonial trade data

    OpenAIRE

    Lavallée, Emmanuelle; Lochard, Julie

    2012-01-01

    The consequences on international trade of country breaks-up have received an increasing attention. This paper investigates the effect of independence on bilateral trade of former French colonies with a focus on Sub-Saharan Africa. Thanks to an original dataset including data on pre-independence bilateral trade we obtain more accurate results. We also show that former French colonies in Sub-Saharan Africa exhibit distinctive post-colonial trade patterns as compared to other former French colo...

  7. Colonial War memories: secret alliances and imagined maps

    OpenAIRE

    Meneses, Maria Paula (eds.); Rosa, Celso; Martins, Bruno Sena

    2014-01-01

    This paper presents preliminary results of a project about the Alcora Exercise. Established between Portugal, South Africa and Rhodesia in 1970, it aimed to fight African nationalist movements and preserve the white sovereignty in Southern Africa. Colonial War was a founding moment of the sociopolitical reality of present day Portugal, and was crucial to independencies of its former African colonies. A thorough understanding of Portuguese Colonial War gains relevance in the con...

  8. Enhanced Bee Colony Algorithm for Complex Optimization Problems

    OpenAIRE

    S.Suriya; R. Deepalakshmi; S.Suresh kannan; Dr.S.P.SHANTHARAJAH

    2012-01-01

    Optimization problems are considered to be one kind of NP hard problems. Usually heuristic approaches are found to provide solutions for NP hard problems. There are a plenty of heuristic algorithmsavailable to solve optimization problems namely: Ant Colony Optimization, Particle Swarm Optimization, Bee Colony Optimization, etc. The basic Bee Colony algorithm, a population based search algorithm, is analyzed to be a novel tool for complex optimization problems. The algorithm mimics the food fo...

  9. Can genetically unrelated individuals join colonies of Ropalidia marginata ?

    OpenAIRE

    Arathi, HS; Gadagkar, Raghavendra

    1996-01-01

    Field and laboratory investigations of the primitively eusocial wasp Ropalidia marginata suggest that worker behaviour cannot be explained satisfactorily either by intra-colony genetic relatedness or by parental manipulation. Besides, polyandry and serial polygyny lead to high levels of intra-colony genetic variability. For these reasons, an attempt was made to explore the role of mutualistic interactions in social evolution.Artificially mixed colonies were created introducing 4-12 one day ol...

  10. Electricity Consumption Prediction Based on SVR with Ant Colony Optimization

    OpenAIRE

    Haijiang Wang; Shanlin Yang

    2013-01-01

    Accurate forecasting of electric load has always been the most important issues in the electricity industry, particularly for developing countries. Due to the various influences, electric load forecasting reveals highly nonlinear characteristics. This paper creates a system for power load forecasting using support vector machine and ant colony optimization. The method of colony optimization is employed to process large amount of data and eliminate. The SVR model with ant colony optimization i...

  11. Deformed Wing Virus Implicated in Overwintering Honeybee Colony Losses ▿

    OpenAIRE

    Highfield, Andrea C.; El Nagar, Aliya; Mackinder, Luke C. M.; Noël, Laure M.-L.J.; Hall, Matthew J.; Martin, Stephen J; Schroeder, Declan C.

    2009-01-01

    The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics tha...

  12. No intracolonial nepotism during colony fissioning in honey bees

    OpenAIRE

    Rangel, Juliana; Mattila, Heather R.; Seeley, Thomas D.

    2009-01-01

    Most species of social insects have singly mated queens, but in some species each queen mates with numerous males to create a colony whose workers belong to multiple patrilines. This colony genetic structure creates a potential for intracolonial nepotism. One context with great potential for such nepotism arises in species, like honey bees, whose colonies reproduce by fissioning. During fissioning, workers might nepotistically choose between serving a young (sister) queen or the old (mother) ...

  13. Improved Ant Colony Clustering Algorithm and Its Performance Study

    OpenAIRE

    Wei Gao

    2015-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational ...

  14. An Improved Ant Colony Routing Algorithm for WSNs

    OpenAIRE

    Tan Zhi; Zhang Hui

    2015-01-01

    Ant colony algorithm is a classical routing algorithm. And it are used in a variety of application because it is economic and self-organized. However, the routing algorithm will expend huge amounts of energy at the beginning. In the paper, based on the idea of Dijkstra algorithm, the improved ant colony algorithm was proposed to balance the energy consumption of networks. Through simulation and comparison with basic ant colony algorithms, it is obvious that improved algorithm can effectively...

  15. Analysis of Ant Colony Optimization and Population-Based Evolutionary Algorithms on Dynamic Problems

    DEFF Research Database (Denmark)

    Lissovoi, Andrei

    exist more complex oscillations that cannot be tracked with a polynomial-size colony. MMAS and (μ+1) EA on Maze We analyse the behaviour of a (μ + 1) EA with genotype diversity on a dynamic fitness function Maze, extended to a finite-alphabet search space. We prove that the (μ + 1) EA is able to track...... the dynamic optimum for finite alphabets up to size μ, while MMAS is able to do so for any finite alphabet size. Parallel Evolutionary Algorithms on Maze. We prove that while a (1 + λ) EA is unable to track the optimum of the dynamic fitness function Maze for offspring population size up to λ = O(n1-ε...... analysis showing how closely the EA can track the dynamically moving optimum over time. These results are also extended to a finite-alphabet search space....

  16. Impaired Virulence and In Vivo Fitness of Colistin-Resistant Acinetobacter baumannii

    OpenAIRE

    López-Rojas, Rafael; Domínguez-Herrera, Juan; McConnell, Michael J.; Docobo-Pérez, Fernando; Smani, Younes; Fernández-Reyes, María; Rivas, Luis; Pachón, Jerónimo

    2011-01-01

    Acinetobacter baumannii (American Type Culture Collection strain 19606) acquires mutations in the pmrB gene during the in vitro development of resistance to colistin. The colistin-resistant strain has lower affinity for colistin, reduced in vivo fitness (competition index, .016), and decreased virulence, both in terms of mortality (0% lethal dose, 6.9 vs 4.9 log colony-forming units) and survival in a mouse model of peritoneal sepsis. These results may explain the low incidence and disseminat...

  17. Varroa-virus interaction in collapsing honey bee colonies.

    Directory of Open Access Journals (Sweden)

    Roy M Francis

    Full Text Available Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI and Deformed Wing Virus (DWV were monitored in a year-long study. We investigated the viral titres in honey bees and varroa mites from 23 colonies (15 apiaries under three treatment conditions: Organic acids (11 colonies, pyrethroid (9 colonies and untreated (3 colonies. Approximately 200 bees were sampled every month from April 2011 to October 2011, and April 2012. The 200 bees were split to 10 subsamples of 20 bees and analysed separately, which allows us to determine the prevalence of virus-infected bees. The treatment efficacy was often low for both treatments. In colonies where varroa treatment reduced the mite load, colonies overwintered successfully, allowing the mites and viruses to be carried over with the bees into the next season. In general, AKI and DWV titres did not show any notable response to the treatment and steadily increased over the season from April to October. In the untreated control group, titres increased most dramatically. Viral copies were correlated to number of varroa mites. Most colonies that collapsed over the winter had significantly higher AKI and DWV titres in October compared to survivors. Only treated colonies survived the winter. We discuss our results in relation to the varroa-virus model developed by Stephen Martin.

  18. Implementasi Algoritma Ant Colony System Dalam Menentukan Optimisasi Network Routing .

    OpenAIRE

    Lubis, Dini Anggraini

    2011-01-01

    Ant Colony System is an algorithm that adapt from ants biologic behavior which the ant colony can hold to find shortest path. Ant Colony System can implement for several optimization problems and one of them is in network routing. Ant colony system that talked in this paper is about optimization cases in network routing called AntNet. The purpose of AntNet is to search shortest path between source node to destination node based the table routing read by AntNet. In this research, it implemente...

  19. Ant- and Ant-Colony-Inspired ALife Visual Art.

    Science.gov (United States)

    Greenfield, Gary; Machado, Penousal

    2015-01-01

    Ant- and ant-colony-inspired ALife art is characterized by the artistic exploration of the emerging collective behavior of computational agents, developed using ants as a metaphor. We present a chronology that documents the emergence and history of such visual art, contextualize ant- and ant-colony-inspired art within generative art practices, and consider how it relates to other ALife art. We survey many of the algorithms that artists have used in this genre, address some of their aims, and explore the relationships between ant- and ant-colony-inspired art and research on ant and ant colony behavior. PMID:26280070

  20. Improved Ant Colony Clustering Algorithm and Its Performance Study.

    Science.gov (United States)

    Gao, Wei

    2016-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational efficiency and accuracy of the ant colony clustering algorithm. The abstraction ant colony clustering algorithm is used to cluster benchmark problems, and its performance is compared with the ant colony clustering algorithm and other methods used in existing literature. Based on similar computational difficulties and complexities, the results show that the abstraction ant colony clustering algorithm produces results that are not only more accurate but also more efficiently determined than the ant colony clustering algorithm and the other methods. Thus, the abstraction ant colony clustering algorithm can be used for efficient multivariate data clustering. PMID:26839533

  1. The Model Characteristics of Physical Fitness in CrossFit

    OpenAIRE

    Vasilii V. Volkov; Viktor N. Seluyanov

    2014-01-01

    The aim of the study is to work out the model characteristics of the physical fitness of CrossFit athletes based on laboratory functional testing (n=10). The analysis of the body composition was conducted using the dual-energy absorptiometry method. The morpho-functional characteristics of the heart were explored using a high-resolution ultrasound scanner. Oxygen consumption at the aerobic-anaerobic threshold and maximum oxygen consumption were determined in a step test on arm and leg cycle e...

  2. Dynamics of the Presence of Israeli Acute Paralysis Virus in Honey Bee Colonies with Colony Collapse Disorder

    Directory of Open Access Journals (Sweden)

    Chunsheng Hou

    2014-05-01

    Full Text Available The determinants of Colony Collapse Disorder (CCD, a particular case of collapse of honey bee colonies, are still unresolved. Viruses including the Israeli acute paralysis virus (IAPV were associated with CCD. We found an apiary with colonies showing typical CCD characteristics that bore high loads of IAPV, recovered some colonies from collapse and tested the hypothesis if IAPV was actively replicating in them and infectious to healthy bees. We found that IAPV was the dominant pathogen and it replicated actively in the colonies: viral titers decreased from April to September and increased from September to December. IAPV extracted from infected bees was highly infectious to healthy pupae: they showed several-fold amplification of the viral genome and synthesis of the virion protein VP3. The health of recovered colonies was seriously compromised. Interestingly, a rise of IAPV genomic copies in two colonies coincided with their subsequent collapse. Our results do not imply IAPV as the cause of CCD but indicate that once acquired and induced to replication it acts as an infectious factor that affects the health of the colonies and may determine their survival. This is the first follow up outside the US of CCD-colonies bearing IAPV under natural conditions.

  3. Honey Bee Colonies Headed by Hyperpolyandrous Queens Have Improved Brood Rearing Efficiency and Lower Infestation Rates of Parasitic Varroa Mites.

    Science.gov (United States)

    Delaplane, Keith S; Pietravalle, Stéphane; Brown, Mike A; Budge, Giles E

    2015-01-01

    A honey bee queen mates on wing with an average of 12 males and stores their sperm to produce progeny of mixed paternity. The degree of a queen's polyandry is positively associated with measures of her colony's fitness, and observed distributions of mating number are evolutionary optima balancing risks of mating flights against benefits to the colony. Effective mating numbers as high as 40 have been documented, begging the question of the upper bounds of this behavior that can be expected to confer colony benefit. In this study we used instrumental insemination to create three classes of queens with exaggerated range of polyandry--15, 30, or 60 drones. Colonies headed by queens inseminated with 30 or 60 drones produced more brood per bee and had a lower proportion of samples positive for Varroa destructor mites than colonies whose queens were inseminated with 15 drones, suggesting benefits of polyandry at rates higher than those normally obtaining in nature. Our results are consistent with two hypotheses that posit conditions that reward such high expressions of polyandry: (1) a queen may mate with many males in order to promote beneficial non-additive genetic interactions among subfamilies, and (2) a queen may mate with many males in order to capture a large number of rare alleles that regulate resistance to pathogens and parasites in a breeding population. Our results are unique for identifying the highest levels of polyandry yet detected that confer colony-level benefit and for showing a benefit of polyandry in particular toward the parasitic mite V. destructor. PMID:26691845

  4. Honey Bee Colonies Headed by Hyperpolyandrous Queens Have Improved Brood Rearing Efficiency and Lower Infestation Rates of Parasitic Varroa Mites.

    Directory of Open Access Journals (Sweden)

    Keith S Delaplane

    Full Text Available A honey bee queen mates on wing with an average of 12 males and stores their sperm to produce progeny of mixed paternity. The degree of a queen's polyandry is positively associated with measures of her colony's fitness, and observed distributions of mating number are evolutionary optima balancing risks of mating flights against benefits to the colony. Effective mating numbers as high as 40 have been documented, begging the question of the upper bounds of this behavior that can be expected to confer colony benefit. In this study we used instrumental insemination to create three classes of queens with exaggerated range of polyandry--15, 30, or 60 drones. Colonies headed by queens inseminated with 30 or 60 drones produced more brood per bee and had a lower proportion of samples positive for Varroa destructor mites than colonies whose queens were inseminated with 15 drones, suggesting benefits of polyandry at rates higher than those normally obtaining in nature. Our results are consistent with two hypotheses that posit conditions that reward such high expressions of polyandry: (1 a queen may mate with many males in order to promote beneficial non-additive genetic interactions among subfamilies, and (2 a queen may mate with many males in order to capture a large number of rare alleles that regulate resistance to pathogens and parasites in a breeding population. Our results are unique for identifying the highest levels of polyandry yet detected that confer colony-level benefit and for showing a benefit of polyandry in particular toward the parasitic mite V. destructor.

  5. Fitting and interpreting occupancy models.

    Science.gov (United States)

    Welsh, Alan H; Lindenmayer, David B; Donnelly, Christine F

    2013-01-01

    We show that occupancy models are more difficult to fit than is generally appreciated because the estimating equations often have multiple solutions, including boundary estimates which produce fitted probabilities of zero or one. The estimates are unstable when the data are sparse, making them difficult to interpret, and, even in ideal situations, highly variable. As a consequence, making accurate inference is difficult. When abundance varies over sites (which is the general rule in ecology because we expect spatial variance in abundance) and detection depends on abundance, the standard analysis suffers bias (attenuation in detection, biased estimates of occupancy and potentially finding misleading relationships between occupancy and other covariates), asymmetric sampling distributions, and slow convergence of the sampling distributions to normality. The key result of this paper is that the biases are of similar magnitude to those obtained when we ignore non-detection entirely. The fact that abundance is subject to detection error and hence is not directly observable, means that we cannot tell when bias is present (or, equivalently, how large it is) and we cannot adjust for it. This implies that we cannot tell which fit is better: the fit from the occupancy model or the fit ignoring the possibility of detection error. Therefore trying to adjust occupancy models for non-detection can be as misleading as ignoring non-detection completely. Ignoring non-detection can actually be better than trying to adjust for it. PMID:23326323

  6. Fitting and interpreting occupancy models.

    Directory of Open Access Journals (Sweden)

    Alan H Welsh

    Full Text Available We show that occupancy models are more difficult to fit than is generally appreciated because the estimating equations often have multiple solutions, including boundary estimates which produce fitted probabilities of zero or one. The estimates are unstable when the data are sparse, making them difficult to interpret, and, even in ideal situations, highly variable. As a consequence, making accurate inference is difficult. When abundance varies over sites (which is the general rule in ecology because we expect spatial variance in abundance and detection depends on abundance, the standard analysis suffers bias (attenuation in detection, biased estimates of occupancy and potentially finding misleading relationships between occupancy and other covariates, asymmetric sampling distributions, and slow convergence of the sampling distributions to normality. The key result of this paper is that the biases are of similar magnitude to those obtained when we ignore non-detection entirely. The fact that abundance is subject to detection error and hence is not directly observable, means that we cannot tell when bias is present (or, equivalently, how large it is and we cannot adjust for it. This implies that we cannot tell which fit is better: the fit from the occupancy model or the fit ignoring the possibility of detection error. Therefore trying to adjust occupancy models for non-detection can be as misleading as ignoring non-detection completely. Ignoring non-detection can actually be better than trying to adjust for it.

  7. Ant Colony Optimization for Capacity Problems

    Directory of Open Access Journals (Sweden)

    Tad Gonsalves

    2015-01-01

    Full Text Available This paper deals with the optimization of the capac ity of a terminal railway station using the Ant Colony Optimization algorithm. The capacity of the terminal station is defined as the number of trains that depart from the station in un it interval of time. The railway capacity optimization problem is framed as a typical symmetr ical Travelling Salesman Problem (TSP, with the TSP nodes representing the train arrival / departure events and the TSP total cost representing the total time-interval of the schedul e. The application problem is then optimized using the ACO algorithm. The simulation experiments validate the formulation of the railway capacity problem as a TSP and the ACO algorithm pro duces optimal solutions superior to those produced by the domain experts.

  8. Modelling the morphology of migrating bacterial colonies

    Science.gov (United States)

    Nishiyama, A.; Tokihiro, T.; Badoual, M.; Grammaticos, B.

    2010-08-01

    We present a model which aims at describing the morphology of colonies of Proteus mirabilis and Bacillus subtilis. Our model is based on a cellular automaton which is obtained by the adequate discretisation of a diffusion-like equation, describing the migration of the bacteria, to which we have added rules simulating the consolidation process. Our basic assumption, following the findings of the group of Chuo University, is that the migration and consolidation processes are controlled by the local density of the bacteria. We show that it is possible within our model to reproduce the morphological diagrams of both bacteria species. Moreover, we model some detailed experiments done by the Chuo University group, obtaining a fine agreement.

  9. Virtual Archaeology in an argentina colonial estancia

    Directory of Open Access Journals (Sweden)

    Florencia Vázquez

    2014-05-01

    Full Text Available This is a first approach to the application of virtual reconstruction techniques of a colonial house. In Argentina it is still uncommon to perform 3D modeling of archaeological sites and especially in historical archeology. As a first step, we used the Google SketchUp to model the country house located on the banks of the Río de la Plata (Buenos Aires. It has historical significance because it belonged to a Spanish councilman, housed hundreds of slaves and was the place where stayed the troops that carried out the Second British Invasion of Buenos Aires. In this case, the 3D modeling was useful for evaluating the future excavationa and activities of preservation of cultural heritage.

  10. Optic disc detection using ant colony optimization

    Science.gov (United States)

    Dias, Marcy A.; Monteiro, Fernando C.

    2012-09-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

  11. Ant Colony Optimization and Hypergraph Covering Problems

    CERN Document Server

    Pat, Ankit

    2011-01-01

    Ant Colony Optimization (ACO) is a very popular metaheuristic for solving computationally hard combinatorial optimization problems. Runtime analysis of ACO with respect to various pseudo-boolean functions and different graph based combinatorial optimization problems has been taken up in recent years. In this paper, we investigate the runtime behavior of an MMAS*(Max-Min Ant System) ACO algorithm on some well known hypergraph covering problems that are NP-Hard. In particular, we have addressed the Minimum Edge Cover problem, the Minimum Vertex Cover problem and the Maximum Weak- Independent Set problem. The influence of pheromone values and heuristic information on the running time is analysed. The results indicate that the heuristic information has greater impact towards improving the expected optimization time as compared to pheromone values. For certain instances of hypergraphs, we show that the MMAS* algorithm gives a constant order expected optimization time when the dominance of heuristic information is ...

  12. The Andersen aerobic fitness test

    DEFF Research Database (Denmark)

    Aadland, Eivind; Terum, Torkil; Mamen, Asgeir;

    2014-01-01

    BACKGROUND: High aerobic fitness is consistently associated with a favorable metabolic risk profile in children. Direct measurement of peak oxygen consumption (VO2peak) is often not feasible, thus indirect tests such as the Andersen test are required in many settings. The present study seeks to...... agreement) were 26.7±125.2 m for test 2 vs. test 1 (p<.001 for mean difference) and 3.9±88.8 m for test 3 vs. test 2 (p = .514 for mean difference). The equation to estimate VO2peak suggested by Andersen et al. (2008) showed a poor fit in the present sample; thus, we suggest a new equation: VO2peak = 23....... Researchers should be aware of the amount of noise in indirect tests that estimate aerobic fitness....

  13. Accelerated Fitting of Stellar Spectra

    CERN Document Server

    Ting, Yuan-Sen; Rix, Hans-Walter

    2016-01-01

    Stellar spectra are often modeled and fit by interpolating within a rectilinear grid of synthetic spectra to derive the stars' labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of parameters separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach -- CHAT (Convex Hull Adaptive Tessellation) -- which includes several new ideas for inexpensively generating a sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock datasets demonstrate that CHAT can reduce the number of required synthetic model calculations by...

  14. The Model Characteristics of Physical Fitness in CrossFit

    Directory of Open Access Journals (Sweden)

    Vasilii V. Volkov

    2014-06-01

    Full Text Available The aim of the study is to work out the model characteristics of the physical fitness of CrossFit athletes based on laboratory functional testing (n=10. The analysis of the body composition was conducted using the dual-energy absorptiometry method. The morpho-functional characteristics of the heart were explored using a high-resolution ultrasound scanner. Oxygen consumption at the aerobic-anaerobic threshold and maximum oxygen consumption were determined in a step test on arm and leg cycle ergometers using a gas-analyzer. The level of the physical fitness of leg muscles in the males and females who took part in the study was satisfactory. However, it was considerably higher than the norm for untrained people. The level of the physical fitness of arm muscles was higher than the average and matched the Master of Sport of International Class standards. The productivity of the cardio-vascular system was much higher than in healthy males and females who do not work out and comparable to the standards for advanced soccer players.

  15. Is a generous Immigration Policy a Way to Rectify for Colonial Injustices?

    OpenAIRE

    Collste, Göran

    2012-01-01

    Migration from former colonies to former colonial powers represents a large part of the 20th century migration. The question discussed in this article is if a generous immigration policy on behalf of persons from former colonies is an appropriate means for the European nations and former colonial powers to compensate for colonial injustices.

  16. Evaluation of counting error due to colony masking in bioaerosol sampling.

    Science.gov (United States)

    Chang, C W; Hwang, Y H; Grinshpun, S A; Macher, J M; Willeke, K

    1994-10-01

    Colony counting error due to indistinguishable colony overlap (i.e., masking) was evaluated theoretically and experimentally. A theoretical model to predict colony masking was used to determine colony counting efficiency by Monte Carlo computer simulation of microorganism collection and development into CFU. The computer simulation was verified experimentally by collecting aerosolized Bacillus subtilis spores and examining micro- and macroscopic colonies. Colony counting efficiency decreased (i) with increasing density of collected culturable microorganisms, (ii) with increasing colony size, and (iii) with decreasing ability of an observation system to distinguish adjacent colonies as separate units. Counting efficiency for 2-mm colonies, at optimal resolution, decreased from 98 to 85% when colony density increased from 1 to 10 microorganisms cm-2, in contrast to an efficiency decrease from 90 to 45% for 5-mm colonies. No statistically significant difference (alpha = 0.05) between experimental and theoretical results was found when colony shape was used to estimate the number of individual colonies in a CFU. Experimental colony counts were 1.2 times simulation estimates when colony shape was not considered, because of nonuniformity of actual colony size and the better discrimination ability of the human eye relative to the model. Colony surface densities associated with high counting accuracy were compared with recommended upper plate count limits and found to depend on colony size and an observation system's ability to identify overlapped colonies. Correction factors were developed to estimate the actual number of collected microorganisms from observed colony counts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7986046

  17. Descision Making on Fitness Landscapes

    CERN Document Server

    Arthur, Rudy

    2016-01-01

    We discuss fitness landscapes and how they can be modified to account for co-evolution. We are interested in using the landscape as a way to model rational decision making in a toy economic system. We develop a model very similar to the Tangled Nature Model of Christensen et. al. that we call the Tangled Decision Model. This is a natural setting for our discussion of co-evolutionary fitness landscapes. We use a Monte Carlo step to simulate decision making and investigate two different decision making procedures.

  18. Countering Coloniality in Educational Research: From Ownership to Answerability

    Science.gov (United States)

    Patel, Lisa

    2014-01-01

    In this theoretical article, I argue for a relational stance on learning as a way of reckoning with educational research as part of the settler colonial structure of the United States. Because of my geopolitical location to the United States as a settler colony, I begin by contrasting the stances of anticolonial and decolonial. I then analyze the…

  19. Heralding the Other: Sousa, Simulacra, and Settler Colonialism

    Science.gov (United States)

    Graham, Matthew C.

    2016-01-01

    This paper addresses the role of music and music education in the perpetuation of settler colonialism (a particular colonial configuration predicated on the expulsion of indigenous people and occupation of indigenous land) within the United States. Using Baudrillard's notion of simulacra, or "false truths," to look at racialized…

  20. Discover for Yourself: An Optimal Control Model in Insect Colonies

    Science.gov (United States)

    Winkel, Brian

    2013-01-01

    We describe the enlightening path of self-discovery afforded to the teacher of undergraduate mathematics. This is demonstrated as we find and develop background material on an application of optimal control theory to model the evolutionary strategy of an insect colony to produce the maximum number of queen or reproducer insects in the colony at…

  1. Mass spectral molecular networking of living microbial colonies

    NARCIS (Netherlands)

    Watrous, J.; Roach, P.; Alexandrov, T.; Heath, B.S.; Yang, J.Y.; Kersten, R.D.; Voort, van der M.; Pogliano, K.; Gross, H.; Raaijmakers, J.; Moore, B.S.; Laskin, J.; Bandeira, N.; Dorrestein, P.C.

    2012-01-01

    Integrating the governing chemistry with the genomics and phenotypes of microbial colonies has been a “holy grail” in microbiology. This work describes a highly sensitive, broadly applicable, and cost-effective approach that allows metabolic profiling of live microbial colonies directly from a Petri

  2. Toxoplasmosis in a colony of New World monkeys

    DEFF Research Database (Denmark)

    Dietz, H.H.; Henriksen, P.; Bille-Hansen, Vivi;

    1997-01-01

    In a colony of New World monkeys five tamarins (Saguinus oedipus, Saguinus labiatus and Leontopithecus rosal. rosal.), three marmosets (Callithrix jacchus and Callithrix pygmaea) and one saki (Pithecia pithecia) died suddenly. The colony comprised 16 marmosets, 10 tamarins and three sakis. The ma...

  3. Ant colonies prefer infected over uninfected nest sites

    DEFF Research Database (Denmark)

    Pontieri, Luigi; Vojvodic, Svjetlana; Graham, Riley;

    2014-01-01

    During colony relocation, the selection of a new nest involves exploration and assessment of potential sites followed by colony movement on the basis of a collective decision making process. Hygiene and pathogen load of the potential nest sites are factors worker scouts might evaluate, given the...

  4. Allee effects and colony collapse disorder in honey bees

    Science.gov (United States)

    We propose a mathematical model to quantify the hypothesis that a major ultimate cause of Colony Collapse Disorder (CCD) in honey bees is the presence of an Allee effect in the growth dynamics of honey bee colonies. In the model, both recruitment of adult bees as well as mortality of adult bees have...

  5. Cormorants as visitors in the Vorsø colony

    DEFF Research Database (Denmark)

    Bregnballe, Thomas; Vinas, Marta Mas; Gregersen, Jens

    2011-01-01

    Like other seabirds Great Cormorants Phalacrocorax carbo sinensis are known to prospect in potential breeding colonies during their first years of life before they settle to breed. Based on daily resightings of colour-ringed cormorants in the old Vorsø colony we examined the difference between...

  6. Seabird colonies in the Melville Bay, Northwest Greenland

    DEFF Research Database (Denmark)

    Boertmann, David; Huffeldt, Nicholas Per

    black guillemot followed by the glaucous gull. However, one colony is of national significance – Sabine Øer, with high numbers of breeding Arctic terns and Sabine’s gulls. Other noteworthy observations were puffins on Thom Ø and many new Iceland gull colonies that extended the known northern breeding...

  7. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... purposes to determine the number of bacterial colonies present on a bacteriological culture...

  8. 36 CFR 7.1 - Colonial National Historical Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Colonial National Historical Park. 7.1 Section 7.1 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.1 Colonial National Historical Park....

  9. Model Specification Searches Using Ant Colony Optimization Algorithms

    Science.gov (United States)

    Marcoulides, George A.; Drezner, Zvi

    2003-01-01

    Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.

  10. Competitive religious entrepreneurs: Christian missionaries and female education in colonial and post-colonial India

    OpenAIRE

    Lankina, Tomila V.; Getachew, Lullit

    2013-01-01

    This article explores the influence of Protestant missionaries on male–female educational inequalities in colonial India. Causal mechanisms drawn from the sociology and economics of religion highlight the importance of religious competition for the provision of public goods. Competition between religious and secular groups spurred missionaries to play a key role in the development of mass female schooling. A case study of Kerala illustrates this. The statistical analysis, with district-lev...

  11. Remote Sensing Image Feature Extracting Based Multiple Ant Colonies Cooperation

    Directory of Open Access Journals (Sweden)

    Zhang Zhi-long

    2014-02-01

    Full Text Available This paper presents a novel feature extraction method for remote sensing imagery based on the cooperation of multiple ant colonies. First, multiresolution expression of the input remote sensing imagery is created, and two different ant colonies are spread on different resolution images. The ant colony in the low-resolution image uses phase congruency as the inspiration information, whereas that in the high-resolution image uses gradient magnitude. The two ant colonies cooperate to detect features in the image by sharing the same pheromone matrix. Finally, the image features are extracted on the basis of the pheromone matrix threshold. Because a substantial amount of information in the input image is used as inspiration information of the ant colonies, the proposed method shows higher intelligence and acquires more complete and meaningful image features than those of other simple edge detectors.

  12. An ant colony algorithm on continuous searching space

    Science.gov (United States)

    Xie, Jing; Cai, Chao

    2015-12-01

    Ant colony algorithm is heuristic, bionic and parallel. Because of it is property of positive feedback, parallelism and simplicity to cooperate with other method, it is widely adopted in planning on discrete space. But it is still not good at planning on continuous space. After a basic introduction to the basic ant colony algorithm, we will propose an ant colony algorithm on continuous space. Our method makes use of the following three tricks. We search for the next nodes of the route according to fixed-step to guarantee the continuity of solution. When storing pheromone, it discretizes field of pheromone, clusters states and sums up the values of pheromone of these states. When updating pheromone, it makes good resolutions measured in relative score functions leave more pheromone, so that ant colony algorithm can find a sub-optimal solution in shorter time. The simulated experiment shows that our ant colony algorithm can find sub-optimal solution in relatively shorter time.

  13. Large area magnetic micropallet arrays for cell colony sorting.

    Science.gov (United States)

    Cox-Muranami, Wesley A; Nelson, Edward L; Li, G P; Bachman, Mark

    2016-01-01

    A new micropallet array platform for adherent cell colony sorting has been developed. The platform consisted of thousands of square plastic pallets, 270 μm by 270 μm on each side, large enough to hold a single colony of cells. Each pallet included a magnetic core, allowing them to be collected with a magnet after being released using a microscope mounted laser system. The micropallets were patterned from 1002F epoxy resist and were fabricated on translucent, gold coated microscope slides. The gold layer was used as seed for electroplating the ferromagnetic cores within every individual pallet. The gold layer also facilitated the release of each micropallet during laser release. This array allows for individual observation, sorting and collection of isolated cell colonies for biological cell colony research. In addition to consistent release and recovery of individual colonies, we demonstrated stable biocompatibility and minimal loss in imaging quality compared to previously developed micropallet arrays. PMID:26606460

  14. Leisure, economy and colonial urbanism: Darjeeling, 1835–1930

    Science.gov (United States)

    BHATTACHARYA, NANDINI

    2013-01-01

    This article posits that the hill station of Darjeeling was a unique form of colonial urbanism. It shifts historiographical interest from major urban centres in colonial India (such as Bombay or Calcutta) and instead attempts a greater understanding of smaller urban centres. In the process, it also interrogates the category of hill stations, which have been understood as exotic and scenic sites rather than as towns that were integral to the colonial economy. In arguing that hill stations, particularly Darjeeling, were not merely the scenic and healthy ‘other’ of the clamorous, dirty and diseased plains of India, it refutes suggestions that the ‘despoiling’ or overcrowding of Darjeeling was incremental to the purposes of its establishment. Instead, it suggests that Darjeeling was part of the colonial mainstream; its urbanization and inclusion into the greater colonial economy was effected from the time of its establishment. Therefore, a constant tension between its exotic and its functional elements persisted throughout. PMID:24273391

  15. Iridovirus and microsporidian linked to honey bee colony decline.

    Directory of Open Access Journals (Sweden)

    Jerry J Bromenshenk

    Full Text Available BACKGROUND: In 2010 Colony Collapse Disorder (CCD, again devastated honey bee colonies in the USA, indicating that the problem is neither diminishing nor has it been resolved. Many CCD investigations, using sensitive genome-based methods, have found small RNA bee viruses and the microsporidia, Nosema apis and N. ceranae in healthy and collapsing colonies alike with no single pathogen firmly linked to honey bee losses. METHODOLOGY/PRINCIPAL FINDINGS: We used Mass spectrometry-based proteomics (MSP to identify and quantify thousands of proteins from healthy and collapsing bee colonies. MSP revealed two unreported RNA viruses in North American honey bees, Varroa destructor-1 virus and Kakugo virus, and identified an invertebrate iridescent virus (IIV (Iridoviridae associated with CCD colonies. Prevalence of IIV significantly discriminated among strong, failing, and collapsed colonies. In addition, bees in failing colonies contained not only IIV, but also Nosema. Co-occurrence of these microbes consistently marked CCD in (1 bees from commercial apiaries sampled across the U.S. in 2006-2007, (2 bees sequentially sampled as the disorder progressed in an observation hive colony in 2008, and (3 bees from a recurrence of CCD in Florida in 2009. The pathogen pairing was not observed in samples from colonies with no history of CCD, namely bees from Australia and a large, non-migratory beekeeping business in Montana. Laboratory cage trials with a strain of IIV type 6 and Nosema ceranae confirmed that co-infection with these two pathogens was more lethal to bees than either pathogen alone. CONCLUSIONS/SIGNIFICANCE: These findings implicate co-infection by IIV and Nosema with honey bee colony decline, giving credence to older research pointing to IIV, interacting with Nosema and mites, as probable cause of bee losses in the USA, Europe, and Asia. We next need to characterize the IIV and Nosema that we detected and develop management practices to reduce honey

  16. In a Peak Fitness Condition?

    DEFF Research Database (Denmark)

    Storm, Rasmus K.; Nielsen, Klaus

    2010-01-01

    managerial efforts with regard to Danish elite sports? The analysis finds the Danish elite sports organization, Team Danmark, well prepared and fit for the future challenges. Still, though, areas such as talent identification and development and division of roles and responsibilities, are in need of...

  17. Inclusive fitness theory and eusociality

    DEFF Research Database (Denmark)

    Abbot, Patrick; Abe, Jun; Alcock, John;

    2011-01-01

    Arising from M. A. Nowak, C. E. Tarnita & E. O. Wilson 466, 1057-1062 (2010); Nowak et al. reply. Nowak et al. argue that inclusive fitness theory has been of little value in explaining the natural world, and that it has led to negligible progress in explaining the evolution of eusociality. However...

  18. Sports Fitness School for Children.

    Science.gov (United States)

    Tacha, Karolyn K.; And Others

    1984-01-01

    The Sports Fitness Program developed at Kansas State University offers children a way to develop or improve skills and learn physical education concepts. This summer program is an alternative to traditional sports programs since activities are not competitive and are less structured. Details of program organization are discussed. (DF)

  19. WellnessCenter clubs fitness

    OpenAIRE

    Torrescasana Carnicé, Roser

    2009-01-01

    Amb aquest projecte és pretén dinamitzar els clubs esportius del tipus fitness. WellnessCenter simula un conjunt de clubs esportius que pertanyen a la mateixa xarxa i per tant es troben tots publicats a la mateixa web encara que cadascun d'ells tingui el seu propi espai.

  20. The Health and Fitness Challenge.

    Science.gov (United States)

    Snelling, Anastasia M.

    1999-01-01

    "Health and Fitness Challenge" program was implemented using the "social marketing model" to raise awareness of health education and related services to students. Collaboration between faculty, student affairs professionals, and students occurred from design through evaluation. The primary goal of bringing students, faculty and staff together was…

  1. Desirable design of hose fittings

    DEFF Research Database (Denmark)

    Voigt, Kristian

    1998-01-01

    This paper describes the primary functionality of a hose fitting. There has been made a discussion about the different parts of the hose assembly - the nipple, the hose and the outer compression parts. The last subject covered is which criteria should be put up for determining what is a good hose...

  2. Collective Memories of Portuguese Colonial Action in Africa: Representations of the Colonial Past among Mozambicans and Portuguese Youths

    Directory of Open Access Journals (Sweden)

    João Feijó

    2010-05-01

    Full Text Available Social representations of the colonization and decolonization processes among young people from a former European colonial power (Portugal and from an African ex-colony (Mozambique were investigated through surveys using open- and closed-ended questions about national history, focusing on the identity functions of collective memories. Hegemonic and contested representations were found of the most prominent events related to Portuguese colonization of Mozambique, arousing a range of collective emotions. A central place is occupied by memories of the Colonial War, which ended with the Carnation Revolution in Portugal and the subsequent independence of the Portuguese African colonies. Overall, the depiction of colonialism was more negative for Mozambican than for Portuguese participants. The violent effects of colonial action were very salient in Mozambican memories, which stressed the most oppressive aspects of the colonial period, associated with slave trade and brutal repression. On the Portuguese side, the idealization of the voyages of discovery persisted, obscuring the most violent effects of colonial expansion. However, collective memories of colonization of former colonizer and former colonized do not simply stand opposed. Both Mozambican and Portuguese participants reported ambivalent feelings towards the colonization process.

  3. Self-Fitting Hearing Aids

    Science.gov (United States)

    Convery, Elizabeth

    2016-01-01

    A self-contained, self-fitting hearing aid (SFHA) is a device that enables the user to perform both threshold measurements leading to a prescribed hearing aid setting and fine-tuning, without the need for audiological support or access to other equipment. The SFHA has been proposed as a potential solution to address unmet hearing health care in developing countries and remote locations in the developed world and is considered a means to lower cost and increase uptake of hearing aids in developed countries. This article reviews the status of the SFHA and the evidence for its feasibility and challenges and predicts where it is heading. Devices that can be considered partly or fully self-fitting without audiological support were identified in the direct-to-consumer market. None of these devices are considered self-contained as they require access to other hardware such as a proprietary interface, computer, smartphone, or tablet for manipulation. While there is evidence that self-administered fitting processes can provide valid and reliable results, their success relies on user-friendly device designs and interfaces and easy-to-interpret instructions. Until these issues have been sufficiently addressed, optional assistance with the self-fitting process and on-going use of SFHAs is recommended. Affordability and a sustainable delivery system remain additional challenges for the SFHA in developing countries. Future predictions include a growth in self-fitting products, with most future SFHAs consisting of earpieces that connect wirelessly with a smartphone and providers offering assistance through a telehealth infrastructure, and the integration of SFHAs into the traditional hearing health-care model. PMID:27072929

  4. Holotransformations of bacterial colonies and genome cybernetics

    Science.gov (United States)

    Ben-Jacob, Eshel; Tenenbaum, Adam; Shochet, Ofer; Avidan, Orna

    1994-01-01

    We present a study of colony transformations during growth of Bacillus subtilis under adverse environmental conditions. It is a continuation of our pilot study of “Adaptive self-organization during growth of bacterial colonies” (Physica A 187 (1992) 378). First we identify and describe the transformations pathway, i.e. the excitation of the branching modes from Bacillus subtilis 168 (grown under diffusion limited conditions) and the phase transformations between the tip-splitting phase (phase T) and the chiral phase (phase C) which belong to the same mode. This pathway shows the evolution of complexity as the bacteria are exposed to adverse growth conditions. We present the morphology diagram of phases T and C as a function of agar concentration and pepton level. As expected, the growth of phase T is ramified (fractal-like or DLA-like) at low pepton level (about 1 g/1) and turns compact at high pepton level (about 10 g/1). The growth of phase C is also ramified at low pepton level and turns denser and finally compact as the pepton level increases. Generally speaking, the colonies develop more complex patterns and higher micro-level organization for more adverse environments. We use the growth velocity as a response function to describe the growth. At low agar concentration (and low pepton level) phase C grows faster than phase T, and for a high agar concentration (about 2%) phase T grows faster. We observe colony transformations between the two phases (phase transformations). They are found to be consistent with the “fastest growing morphology” selection principle adopted from azoic systems. The transformations are always from the slower phase to the faster one. Hence, we observe T→ C transformations at low agar concentrations and C→ T transformations at high agar concentrations. We have observed both localized and extended transformations. Usually, the transformations are localized for more adverse growth conditions, and extended for growth conditions

  5. Ecological conditions favoring budding in colonial organisms under environmental disturbance.

    Directory of Open Access Journals (Sweden)

    Mayuko Nakamaru

    Full Text Available Dispersal is a topic of great interest in ecology. Many organisms adopt one of two distinct dispersal tactics at reproduction: the production of small offspring that can disperse over long distances (such as seeds and spawned eggs, or budding. The latter is observed in some colonial organisms, such as clonal plants, corals and ants, in which (superorganisms split their body into components of relatively large size that disperse to a short distance. Contrary to the common dispersal viewpoint, short-dispersal colonial organisms often flourish even in environments with frequent disturbances. In this paper, we investigate the conditions that favor budding over long-distance dispersal of small offspring, focusing on the life history of the colony growth and the colony division ratio. These conditions are the relatively high mortality of very small colonies, logistic growth, the ability of dispersers to peacefully seek and settle unoccupied spaces, and small spatial scale of environmental disturbance. If these conditions hold, budding is advantageous even when environmental disturbance is frequent. These results suggest that the demography or life history of the colony underlies the behaviors of the colonial organisms.

  6. Colony specificity and chemotaxis in the compound ascidian Botryllus schlosseri.

    Science.gov (United States)

    Cima, Francesca; Sabbadin, Armando; Zaniolo, Giovanna; Ballarin, Loriano

    2006-11-01

    We re-investigated the behavior of hemocytes during the non-fusion (rejection) reaction between genetically incompatible colonies of the ascidian Botryllus schlosseri. In the course of the reaction, hemocytes - mainly morula cells - crowd inside the blind ends of marginal vascular vessels (known as ampullae) of the colonial leading edge (LE) facing the foreign colony which suggests the occurrence of chemotactic attraction of circulating hemocytes towards the ampullar lumen. Then, cells migrate, through the ampullar tips, into the partially fused tunics and contribute to the formation of the necrotic spots along the contact borders which characterize the reaction. Studies on histological sections clearly indicate that, although morula cell concentration is always higher in ampullae of the LE than in those of the lateral (L) part of the colony, their frequency significantly increases in LE ampullae of rejecting colonies with respect to LE ampullae of both fusing and isolated colonies. In addition, in vitro chemotaxis experiments demonstrated that blood plasma from incompatible colonies can stimulate morula cell migration through polycarbonate filters and this passage is inhibited by antibodies raised against mammalian pro-inflammatory cytokines. The possible nature and role of molecules recognized by anti-cytokine antibodies in hemocyte migration are discussed. PMID:16962802

  7. Dynamical Models of Task Organization in Social Insect Colonies.

    Science.gov (United States)

    Kang, Yun; Theraulaz, Guy

    2016-05-01

    The organizations of insect societies, such as division of labor, task allocation, collective regulation, mass action responses, have been considered as main reasons for the ecological success. In this article, we propose and study a general modeling framework that includes the following three features: (a) the average internal response threshold for each task (the internal factor); (b) social network communications that could lead to task switching (the environmental factor); and (c) dynamical changes of task demands (the external factor). Since workers in many social insect species exhibit age polyethism, we also extend our model to incorporate age polyethism in which worker task preferences change with age. We apply our general modeling framework to the cases of two task groups: the inside colony task versus the outside colony task. Our analytical study of the models provides important insights and predictions on the effects of colony size, social communication, and age-related task preferences on task allocation and division of labor in the adaptive dynamical environment. Our study implies that the smaller size colony invests its resource for the colony growth and allocates more workers in the risky tasks such as foraging while the larger colony shifts more workers to perform the safer tasks inside the colony. Social interactions among different task groups play an important role in shaping task allocation depending on the relative cost and demands of the tasks. PMID:27125656

  8. Ant Colony Optimisation for Backward Production Scheduling

    Directory of Open Access Journals (Sweden)

    Leandro Pereira dos Santos

    2012-01-01

    Full Text Available The main objective of a production scheduling system is to assign tasks (orders or jobs to resources and sequence them as efficiently and economically (optimised as possible. Achieving this goal is a difficult task in complex environment where capacity is usually limited. In these scenarios, finding an optimal solution—if possible—demands a large amount of computer time. For this reason, in many cases, a good solution that is quickly found is preferred. In such situations, the use of metaheuristics is an appropriate strategy. In these last two decades, some out-of-the-shelf systems have been developed using such techniques. This paper presents and analyses the development of a shop-floor scheduling system that uses ant colony optimisation (ACO in a backward scheduling problem in a manufacturing scenario with single-stage processing, parallel resources, and flexible routings. This scenario was found in a large food industry where the corresponding author worked as consultant for more than a year. This work demonstrates the applicability of this artificial intelligence technique. In fact, ACO proved to be as efficient as branch-and-bound, however, executing much faster.

  9. Loading pattern optimization using ant colony algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Hoareau, Fabrice [EDF R and D, Clamart (France)

    2008-07-01

    Electricite de France (EDF) operates 58 nuclear power plants (NPP), of the Pressurized Water Reactor type. The loading pattern optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R and D has developed automatic optimization tools that assist the experts. LOOP is an industrial tool, developed by EDF R and D and based on a simulated annealing algorithm. In order to improve the results of such automatic tools, new optimization methods have to be tested. Ant Colony Optimization (ACO) algorithms are recent methods that have given very good results on combinatorial optimization problems. In order to evaluate the performance of such methods on loading pattern optimization, direct comparisons between LOOP and a mock-up based on the Max-Min Ant System algorithm (a particular variant of ACO algorithms) were made on realistic test-cases. It is shown that the results obtained by the ACO mock-up are very similar to those of LOOP. Future research will consist in improving these encouraging results by using parallelization and by hybridizing the ACO algorithm with local search procedures. (author)

  10. Loading pattern optimization using ant colony algorithm

    International Nuclear Information System (INIS)

    Electricite de France (EDF) operates 58 nuclear power plants (NPP), of the Pressurized Water Reactor type. The loading pattern optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R and D has developed automatic optimization tools that assist the experts. LOOP is an industrial tool, developed by EDF R and D and based on a simulated annealing algorithm. In order to improve the results of such automatic tools, new optimization methods have to be tested. Ant Colony Optimization (ACO) algorithms are recent methods that have given very good results on combinatorial optimization problems. In order to evaluate the performance of such methods on loading pattern optimization, direct comparisons between LOOP and a mock-up based on the Max-Min Ant System algorithm (a particular variant of ACO algorithms) were made on realistic test-cases. It is shown that the results obtained by the ACO mock-up are very similar to those of LOOP. Future research will consist in improving these encouraging results by using parallelization and by hybridizing the ACO algorithm with local search procedures. (author)

  11. Seeing How Fitting Process Works

    CERN Document Server

    Montalbano, Vera

    2016-01-01

    A common problem in teaching Physics in secondary school is due to the gap in terms of difficulty between the physical concepts and the mathematical tools which are necessary to study them quantitatively. Advanced statistical estimators are commonly introduced only a couple of years later than some common physical topics, such as e.g. the electronic circuit analysis. Filling this gap with alternative methods appears to be opportune, in order to let the students reach a full comprehension of the issue they are facing with. In this work we use a smartphone camera and GeoGebra to propose a visual method for understanding the physical meaning of a fitting process. The time constant of an RC circuit is estimated by fitting the discharge curve of a capacitor visualized on the screen of an oscilloscope.

  12. Hearing Aid Fitting & Electrophysiologic Procedure

    Directory of Open Access Journals (Sweden)

    Bahram Jalaei

    2001-05-01

    Full Text Available Rehabilitation of deaf individual is one of the important subjects that has attracted attention of many researchers during past centuries. Different opinions have been established in this direction. Electrophysiologic tests were established and developed parallel to developments in rehabilitation. Therefore, opinion of using electrophysiologic test for evaluation and fitting of hearing aid became gradually popular. Ultimately, the electrophysiologic tests are used in evaluation and fitting of hearing aid in two ways: 1-Direct way 2- Indirect way "nIn direct way aided ABR is obtained and special attention is paid to wave V. This technique has many difficulties. Inindirect way, electrophysiologic tests such, ECochG, OAE and ABR, AMLR, ALR and P300 and other objective tests are used, especially in infants and neonates for evaluating the state of hearing. Researches are continuing in this field. It is probable to have aided electrophysiologic responses with speech stimuli in near future.

  13. Estimating the net electricity energy generation and demand using the ant colony optimization approach. Case of Turkey

    International Nuclear Information System (INIS)

    This paper presents Turkey's net electricity energy generation and demand based on economic indicators. Forecasting model for electricity energy generation and demand is first proposed by the ant colony optimization (ACO) approach. It is multi-agent system in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. Ant colony optimization electricity energy estimation (ACOEEE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear electricity energy generation and demand (linearACOEEGE and linear ACOEEDE) and quadratic energy generation and demand (quadraticACOEEGE and quadratic ACOEEDE). Quadratic models for both generation and demand provided better fit solution due to the fluctuations of the economic indicators. The ACOEEGE and ACOEEDE models indicate Turkey's net electricity energy generation and demand until 2025 according to three scenarios. (author)

  14. Energy Aware Reliable Routing Protocol (EARRP for Mobile AdHoc Networks Using Bee Foraging Behavior and Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    K.G.Santhiya

    2012-03-01

    Full Text Available Energy aware reliable routing in mobile ad hoc networks is an astonishing task and in this paper we propose to design, develop such protocol which will be a good solution. For developing such protocol EARRP, two swarm intelligence techniques are involved namely ant colony optimization and bee colony foraging behavior. For optimization, we proposed adaptive solutions in order to estimate MAC overhead, link eminence and residual energy. After estimating the above said metrics, the fitness function is derived out. The performance metrics taken are overhead, delay, packet delivery ratio and total energy consumed by nodes. By simulation results the proposed EARRP outperforms AODV by reducing energy consumption, overhead and delay. Also EARRP gains better packet delivery ratio than that of AODV.

  15. Estimating the net electricity energy generation and demand using the ant colony optimization approach. Case of Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Toksari, M. Duran [Engineering Faculty, Industrial Engineering Department, Erciyes University, 38039 Kayseri (Turkey)

    2009-03-15

    This paper presents Turkey's net electricity energy generation and demand based on economic indicators. Forecasting model for electricity energy generation and demand is first proposed by the ant colony optimization (ACO) approach. It is multi-agent system in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. Ant colony optimization electricity energy estimation (ACOEEE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear electricity energy generation and demand (linear{sub A}COEEGE and linear ACOEEDE) and quadratic energy generation and demand (quadratic{sub A}COEEGE and quadratic ACOEEDE). Quadratic models for both generation and demand provided better fit solution due to the fluctuations of the economic indicators. The ACOEEGE and ACOEEDE models indicate Turkey's net electricity energy generation and demand until 2025 according to three scenarios. (author)

  16. Estimating the net electricity energy generation and demand using the ant colony optimization approach: Case of Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Toksari, M. Duran [Engineering Faculty, Industrial Engineering Department, Erciyes University, 38039 Kayseri (Turkey)], E-mail: dtoksari@erciyes.edu.tr

    2009-03-15

    This paper presents Turkey's net electricity energy generation and demand based on economic indicators. Forecasting model for electricity energy generation and demand is first proposed by the ant colony optimization (ACO) approach. It is multi-agent system in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. Ant colony optimization electricity energy estimation (ACOEEE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear electricity energy generation and demand (linear{sub A}COEEGE and linear ACOEEDE) and quadratic energy generation and demand (quadratic{sub A}COEEGE and quadratic ACOEEDE). Quadratic models for both generation and demand provided better fit solution due to the fluctuations of the economic indicators. The ACOEEGE and ACOEEDE models indicate Turkey's net electricity energy generation and demand until 2025 according to three scenarios.

  17. Estimating the net electricity energy generation and demand using the ant colony optimization approach: Case of Turkey

    International Nuclear Information System (INIS)

    This paper presents Turkey's net electricity energy generation and demand based on economic indicators. Forecasting model for electricity energy generation and demand is first proposed by the ant colony optimization (ACO) approach. It is multi-agent system in which the behavior of each ant is inspired by the foraging behavior of real ants to solve optimization problem. Ant colony optimization electricity energy estimation (ACOEEE) model is developed using population, gross domestic product (GDP), import and export. All equations proposed here are linear electricity energy generation and demand (linearACOEEGE and linear ACOEEDE) and quadratic energy generation and demand (quadraticACOEEGE and quadratic ACOEEDE). Quadratic models for both generation and demand provided better fit solution due to the fluctuations of the economic indicators. The ACOEEGE and ACOEEDE models indicate Turkey's net electricity energy generation and demand until 2025 according to three scenarios

  18. Physical fitness, aging, and sexuality.

    OpenAIRE

    Bortz, W M; D. H. Wallace

    1999-01-01

    Sexuality is a major quality-of-life issue, even into advanced age. Although relatively few studies have addressed sexuality, most studies have emphasized the decline in both sexual performance and satisfaction with aging. In an effort to assess possible positive modifiers of the decline, we included questions concerning sexuality in a multipurpose 90-item questionnaire submitted to members of the Fifty Plus Fitness Association based in Stanford, California. This group is unique in its commit...

  19. Solving Integer Programming Problems by Using Artificial Bee Colony Algorithm

    Science.gov (United States)

    Akay, Bahriye; Karaboga, Dervis

    This paper presents a study that applies the Artificial Bee Colony algorithm to integer programming problems and compares its performance with those of Particle Swarm Optimization algorithm variants and Branch and Bound technique presented to the literature. In order to cope with integer programming problems, in neighbour solution production unit, solutions are truncated to the nearest integer values. The experimental results show that Artificial Bee Colony algorithm can handle integer programming problems efficiently and Artificial Bee Colony algorithm can be considered to be very robust by the statistics calculated such as mean, median, standard deviation.

  20. [Morphological diversity of Pandorina morum (Mull.) Vory (Volvocaceae) colonies].

    Science.gov (United States)

    Voĭtekhovskiĭ, Iu L

    2001-01-01

    Morphological variability of polyhedral colonies of green algae (Volvocaceae) were studied using some elements of combinative theory of polyhedron and the theory of diophantine equations. These colonies are considered as results of self-organization according to topological regularities of sphere dissection by convex polygons. It was shown that in three-dimensional Euclidean space for each colony of Pandorina morum (Müll.) Bory only three different forms are possible. One of them has no plane of symmetry and, thus, has two enantiomorphous varieties. It is suggested that frequency spectrum of forms can be used as potential indicator of environment pollution. PMID:11605552