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Sample records for black queen cell

  1. Brain transcriptomes of honey bees (Apis mellifera experimentally infected by two pathogens: Black queen cell virus and Nosema ceranae

    Directory of Open Access Journals (Sweden)

    Vincent Doublet

    2016-12-01

    Full Text Available Regulation of gene expression in the brain plays an important role in behavioral plasticity and decision making in response to external stimuli. However, both can be severely affected by environmental factors, such as parasites and pathogens. In honey bees, the emergence and re-emergence of pathogens and potential for pathogen co-infection and interaction have been suggested as major components that significantly impaired social behavior and survival. To understand how the honey bee is affected and responds to interacting pathogens, we co-infected workers with two prevalent pathogens of different nature, the positive single strand RNA virus Black queen cell virus (BQCV, and the Microsporidia Nosema ceranae, and explored gene expression changes in brains upon single infections and co-infections. Our data provide an important resource for research on honey bee diseases, and more generally on insect host-pathogen and pathogen-pathogen interactions. Raw and processed data are publicly available in the NCBI/GEO database: (http://www.ncbi.nlm.nih.gov/geo/ under accession number GSE81664.

  2. Rearing Drones in Queen Cells of Apis mellifera Honey Bees

    Directory of Open Access Journals (Sweden)

    Goras Georgios

    2016-12-01

    Full Text Available We investigated the rearing of drone larvae grafted in queen cells. From the 1200 drone larvae that were grafted during spring and autumn, 875 were accepted (72.9% and reared as queens. Drone larvae in false queen cells received royal jelly of the same composition and of the same amounts as queen larvae. Workers capped the queen cells as if they were drones, 9-10 days after the egg laying. Out of 60 accepted false queen cells, 21 (35% were capped. The shape of false queen cells with drone larvae is unusually long with a characteristically elongate tip which is probably due to the falling of larvae. Bees start the destruction of the cells when the larvae were 3 days old and maximised it before and after capping. Protecting false queen cells in the colony by wrapping, reversing them upside down, or placing in a horizontal position, did not help. The only adult drones that emerged from the false queen cells were those protected in an incubator and in push-in cages. Adult drones from false queen cells had smaller wings, legs, and proboscis than regular drones. The results of this study verify previous reports that the bees do not recognise the different sex of the larvae at least at the early stage of larval development. The late destruction of false queen cells, the similarity in quality and quantity of the produced royal jelly, and the bigger drone cells, allow for the use of drone larvae in cups for the production of royal jelly.

  3. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....

  4. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  5. Characteristics of Honey Bee (Apis Mellifera Carnica, Pollman 1879 Queens Reared in Slovenian Commercial Breeding Stations

    Directory of Open Access Journals (Sweden)

    Gregorc Aleš

    2015-12-01

    Full Text Available In this three-year-trial study, we examined the quality of mated queens based on morphological and physiology traits. At each location, sister queen bees were reared each year from one Apis mellifera carnica breeder queen. Queens were also reared and mated in different locations. Altogether, we sampled and analysed 324 queens from 27 apiaries in 2006, 288 queens from 24 apiaries in 2008, and 276 queens from 23 apiaries in 2010. Nine queens from each apiary were sampled and dissected for morphological analyses and Nosema ceranae (N. ceranae spores, if present, were quantified. Three queens from each apiary were prepared and tested for four viruses: acute bee paralysis virus (ABPV, black queen cell virus (BQCV, deformed wing virus (DWV, and sacbrood virus (SBV. The highest average queen weight of 209.49 ± 9.82 mg was detected in 2008. The highest average ovary weight of 78.67 ± 11.86 mg was detected in 2010, and the highest number of ovarioles was 161.59 ± 8.70 in 2006. The average number of spermatozoa in queens ranged from 3.30 x 106 in 2006 to 5.23 x 106 in 2010. Nosema ceranae spores were found in queens sampled in 2008 and 2010. Viruses were discovered sporadically during the queen testing periods from 2006 - 2010. This study importantly demonstrates that queens from rearing stations require regular evaluation for morphological and physiological changes as well as for infection from harmful pathogens. These results could also be used in establishing relevant commercial standards for rearing quality queens.

  6. The Effects of Pesticides on Queen Rearing and Virus Titers in Honey Bees (Apis mellifera L.

    Directory of Open Access Journals (Sweden)

    Gloria DeGrandi-Hoffman

    2013-01-01

    Full Text Available The effects of sublethal pesticide exposure on queen emergence and virus titers were examined. Queen rearing colonies were fed pollen with chlorpyrifos (CPF alone (pollen-1 and with CPF and the fungicide Pristine® (pollen-2. Fewer queens emerged when larvae from open foraging (i.e., outside colonies were reared in colonies fed pollen-1 or 2 compared with when those larvae were reared in outside colonies. Larvae grafted from and reared in colonies fed pollen-2 had lower rates of queen emergence than pollen-1 or outside colonies. Deformed wing virus (DWV and black queen cell virus were found in nurse bees from colonies fed pollen-1 or 2 and in outside colonies. The viruses also were detected in queen larvae. However, we did not detect virus in emerged queens grafted from and reared in outside colonies. In contrast, DWV was found in all emerged queens grafted from colonies fed pollen-1 or 2 either reared in outside hives or those fed pollen-1 or 2. The results suggest that sublethal exposure of CPF alone but especially when Pristine® is added reduces queen emergence possibly due to compromised immunity in developing queens.

  7. Diet and cell size both affect queen-worker differentiation through DNA methylation in honey bees (Apis mellifera, Apidae.

    Directory of Open Access Journals (Sweden)

    Yuan Yuan Shi

    Full Text Available BACKGROUND: Young larvae of the honey bee (Apis mellifera are totipotent; they can become either queens (reproductives or workers (largely sterile helpers. DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation. METHODOLOGY/PRINCIPAL FINDINGS: We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene dynactin p62; as well as morphological characteristics of adult bees developed either from larvae fed with worker jelly or royal jelly; and larvae raised in either queen or worker cells. We show that both diet type and cell size contributed to the queen-worker differentiation, and that the two factors affected different methylation sites inside the same gene dynactin p62. CONCLUSIONS/SIGNIFICANCE: We confirm previous findings that Dnmt3 plays a critical role in honey bee caste differentiation. Further, we show for the first time that cell size also plays a role in influencing larval development when diet is kept the same.

  8. Diet and cell size both affect queen-worker differentiation through DNA methylation in honey bees (Apis mellifera, Apidae).

    Science.gov (United States)

    Shi, Yuan Yuan; Huang, Zachary Y; Zeng, Zhi Jiang; Wang, Zi Long; Wu, Xiao Bo; Yan, Wei Yu

    2011-04-26

    Young larvae of the honey bee (Apis mellifera) are totipotent; they can become either queens (reproductives) or workers (largely sterile helpers). DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation. We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene dynactin p62; as well as morphological characteristics of adult bees developed either from larvae fed with worker jelly or royal jelly; and larvae raised in either queen or worker cells. We show that both diet type and cell size contributed to the queen-worker differentiation, and that the two factors affected different methylation sites inside the same gene dynactin p62. We confirm previous findings that Dnmt3 plays a critical role in honey bee caste differentiation. Further, we show for the first time that cell size also plays a role in influencing larval development when diet is kept the same.

  9. Diet and Cell Size Both Affect Queen-Worker Differentiation through DNA Methylation in Honey Bees (Apis mellifera, Apidae)

    OpenAIRE

    Shi, Yuan Yuan; Huang, Zachary Y.; Zeng, Zhi Jiang; Wang, Zi Long; Wu, Xiao Bo; Yan, Wei Yu

    2011-01-01

    BACKGROUND: Young larvae of the honey bee (Apis mellifera) are totipotent; they can become either queens (reproductives) or workers (largely sterile helpers). DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation. METHODOLOGY/PRINCIPAL FINDINGS: We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene ...

  10. THE QUEEN

    African Journals Online (AJOL)

    of being devastated. Maybe this is dependant on which 'camp' the viewer finds him- / herself supporting. The film portrays his means of coping with this 'loss' as lashing out towards his mother, Queen. Elizabeth, and the mother-son relationship highlighted by the film is one characterised by distance and emotional frigidity.

  11. Black silicon solar cells with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by maskless reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Four different methods to obtain blackened bus-bar strings were compared with respect to reflectance, and two of these methods (i.e., oxidized copper and etched solder) were used to fabricate functional allblack solar 9-cell panels. The black bus-bars (e.......g., by oxidized copper) have a reflectance below 3% in the entire visible wavelength range. The combination of black silicon cells and blackened bus-bars results in aesthetic, all-black panels based on conventional, front-contacted solar cells without compromising efficiency....

  12. Mitosis and cell death in the optic lobes of workers, queens and ...

    Indian Academy of Sciences (India)

    ... the differences in the compound eyes in adults of these classes are achieved. The results showed that OL differentiation follows a similar pattern in the three classes of individuals studied, without structural differences in their development. The main non-structural differences involve cell division, mortality rates and timing.

  13. Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis.

    Science.gov (United States)

    Roat, Thaisa Cristina; Landim, Carminda da Cruz

    2010-09-01

    Colonies of the honey bee, Apis mellifera, consist of males and two female castes: workers and queens. The castes and males from A. mellifera have a distinct morphology, physiology and behaviour that correlate with their roles in the society and are characterized by some brain polymorphisms. Compound eyes are one of the characteristics that differ among the castes and sexes. A. mellifera is a holometabolous insect; therefore, the development of adult organs during metamorphosis, which will produce these differences, requires the precise coordination of three main programmed cellular processes: proliferation, differentiation and death. These processes take place simultaneously during pupation. Our purpose was to investigate cell division and death in the optic lobes (OL) of workers, queens and males during pupation to identify how the differences in the compound eyes in adults of these classes are achieved. The results showed that OL differentiation follows a similar pattern in the three classes of individuals studied, without structural differences in their development. The main non-structural differences involve cell division, mortality rates and timing. The results suggest a modelling of the brain during differentiation, which contributes to the specific functions of each individual class.

  14. Vertical transmission of honey bee viruses in a Belgian queen breeding program.

    Science.gov (United States)

    Ravoet, Jorgen; De Smet, Lina; Wenseleers, Tom; de Graaf, Dirk C

    2015-03-14

    The Member States of European Union are encouraged to improve the general conditions for the production and marketing of apicultural products. In Belgium, programmes on the restocking of honey bee hives have run for many years. Overall, the success ratio of this queen breeding programme has been only around 50%. To tackle this low efficacy, we organized sanitary controls of the breeding queens in 2012 and 2014. We found a high quantity of viruses, with more than 75% of the egg samples being infected with at least one virus. The most abundant viruses were Deformed Wing Virus and Sacbrood Virus (≥40%), although Lake Sinai Virus and Acute Bee Paralysis Virus were also occasionally detected (between 10-30%). In addition, Aphid Lethal Paralysis Virus strain Brookings, Black Queen Cell Virus, Chronic Bee Paralysis Virus and Varroa destructor Macula-like Virus occurred at very low prevalences (≤5%). Remarkably, we found Apis mellifera carnica bees to be less infected with Deformed Wing Virus than Buckfast bees (p Colony Collapse Disorder. Moreover, negative-strand detection of Sacbrood Virus in eggs was demonstrated for the first time. High pathogen loads were observed in this sanitary control program. We documented for the first time vertical transmission of some viruses, as well as significant differences between two honey bee races in being affected by Deformed Wing Virus. Nevertheless, we could not demonstrate a correlation between the presence of viruses and queen breeding efficacies.

  15. Queen signaling in social wasps

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Bonckaert, Wim; Wenseleers, Tom

    2014-01-01

    , thereby arguing against fast evolution of signals as a result of a queen-worker arms race ensuing from queen control. Lastly, levels of worker reproduction in these species correspond well with their average colony kin structures, as predicted by the queen signaling hypothesis but not the queen control...... hypothesis. Altogether, this correlative yet comprehensive analysis provides compelling evidence that honest signaling explains levels of reproductive division of labor in social wasps....

  16. Queen Mary Two Step

    OpenAIRE

    Melin, Mats H.

    2007-01-01

    n/a Dance devised by Mats Melin in October 2007 whilst teaching Ceilidh dancing on board the cruise ship Queen Mary 2 crossing the Atlantic from Southampton to New York and back with the Ian Muir Sound from Prestwick. The segment of music featured is from Ian Muir Scottish Dance Band's recording of an Eva Three step.

  17. Bee Queen Breeding Methods - Review

    Directory of Open Access Journals (Sweden)

    Silvia Patruica

    2016-05-01

    Full Text Available The biological potential of a bee family is mainly generated by the biological value of the queen. Whether we grow queens widely or just for our own apiaries, we must consider the acquisition of high-quality biological material, and also the creation of optimal feeding and caring conditions, in order to obtain high genetic value queens. Queen breeding technology starts with the setting of hoeing families, nurse families, drone-breeding families – necessary for the pairing of young queens, and also of the families which will provide the bees used to populate the nuclei where the next queens will hatch. The complex of requirements for the breeding of good, high-production queens is sometimes hard to met, under the application of artificial methods. The selection of breeding method must rely on all these requirements and on the beekeeper’s level of training.

  18. Prudent sperm use by leaf-cutter ant queens

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Baer, Boris; Dreier, Stéphanie Agnès Jeanine

    2009-01-01

    In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps......), reproduction is usually monopolized by one or relatively few queens, who mate only during a brief period early in life and store sperm for later use. The queens of some ants are particularly long-lived and have the potential to produce millions of offspring during their life. To do so, queens store many sperm...... cells, and this sperm must remain viable throughout the years of storage. Queens should also be under strong selection to use stored sperm prudently when fertilizing eggs. We used the leaf-cutter ant Atta colombica to investigate the dynamics of sperm use during egg fertilization. We show that queens...

  19. How Honeybees Defy Gravity with Royal Jelly to Raise Queens.

    Science.gov (United States)

    Buttstedt, Anja; Mureşan, Carmen I; Lilie, Hauke; Hause, Gerd; Ihling, Christian H; Schulze, Stefan-H; Pietzsch, Markus; Moritz, Robin F A

    2018-03-02

    The female sex in honeybees (Apis spp.) comprises a reproductive queen and a sterile worker caste. Nurse bees feed all larvae progressively with a caste-specific food jelly until the prepupal stage. Only those larvae that are exclusively fed a large amount of royal jelly (RJ) develop into queens [1]. RJ is a composite secretion of two specialized head glands: the mandibular glands, which produce mainly fatty acids [2], and the hypopharyngeal glands, which contribute proteins, primarily belonging to the major royal jelly protein (MRJP) family [3]. Past research on RJ has focused on its nutritional function and overlooked its central role with regard to the orientation of the larva in the royal brood cell. Whereas workers are reared in the regular horizontal cells of the comb, the queen cells are specifically built outside of the normal comb area to accommodate for the larger queen [4, 5]. These cells hang freely along the bottom of the comb and are vertically oriented, opening downward [6]. Queen larvae are attached by their RJ diet to the cell ceiling. Thus, the physical properties of RJ are central to successful retention of larvae in the cell. Here, we show that the main protein of RJ (MRJP1) polymerizes in complex with another protein, apisimin, into long fibrous structures that build the basis for the high viscosity of RJ to hold queen larvae on the RJ surface. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  20. Dye-sensitized solar cells fabricated with black raspberry, black carrot and rosella juice

    Science.gov (United States)

    Tekerek, S.; Kudret, A.; Alver, Ü.

    2011-10-01

    In this work, dye sensitized solar cells (DSSC's) were constructed from black raspberry ( Rubus Ideaus), black carrot ( Daucuscarota L.) and rosella juice ( Hibiscus Sabdariffa L.). In order to fabricate a DSSC the fluorine-doped tin (IV) oxide (FTO) thin films obtained by using spray pyrolysis technique were used as a substrate. TiO2 films on FTO layers were prepared by doctor-blading technique. Platinum-coated counter electrode and liquid Iodide/Iodine electrolyte solution were used to fabricate DSSC's. The efficiencies of solar cells produced with black carrot, rosella and black raspberry juice were calculated as 0.25%, 0.16% and 0.16% respectively, under a sunny day in Kahramanmaraş-Turkey.

  1. A contribution to queens graphs

    DEFF Research Database (Denmark)

    Barat, Janos

    A graph $G$ is a queens graph if the vertices of $G$ can be mapped to queens on the chessboard such that two vertices are adjacent if and only if the corresponding queens attack each other, i.e. they are in horizontal, vertical or diagonal position. We prove a conjecture of Beineke, Broere...... and Henning that the Cartesian product of an odd cycle and a path is a queens graph. We show that the same does not hold for two odd cycles. % is not representable in the same way. The representation of the Cartesian product of an odd cycle and an even cycle remains an open problem. We also prove...... constructively that any finite subgraph of the grid or the hexagonal grid is a queens graph....

  2. Impact of Thiamethoxam on Honey Bee Queen (Apis mellifera carnica) Reproductive Morphology and Physiology.

    Science.gov (United States)

    Gajger, Ivana Tlak; Sakač, Martina; Gregorc, Aleš

    2017-09-01

    High honey bee losses around the world have been linked in part by the regular use of neonicotinoids in agriculture. In light of the current situation, the aim of this study was to investigate the effects of thiamethoxam on the development of the reproductive system and physiology in the honey bee queen. Two experimental groups of honey bee queen larvae were treated with thiamethoxam during artificial rearing, applied via artificial feed in two cycles. In the first rearing cycle, honey bee larvae received a single treatment dose (4.28 ng thiamethoxam/queen larva on the 4th day after larvae grafting in artificial queen cells), while the second honey bee queen rearing cycle received a double treatment dose (total of 8.56 ng thiamethoxam/queen larva on the 4th and 5th day after larvae grafting in artificial queen cells). After emerging, queens were anesthetized and weighed, and after mating with drones were anesthetized, weighed, and sectioned. Ovary mass and number of stored sperm were determined. Body weight differed between untreated and treated honey bee queens. The results also show a decrease in the number of sperm within honey bee queen spermathecae that received the double thiamethoxam dose.

  3. Individual Recognition in Ant Queens

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Heinze, Jürgen

    2005-01-01

    Personal relationships are the cornerstone of vertebrate societies, but insect societies are either too large for individual recognition, or their members were assumed to lack the necessary cognitive abilities 1 and 2 . This paradigm has been challenged by the recent discovery that paper wasps...... recognize each other's unique facial color patterns [3] . Individual recognition is advantageous when dominance hierarchies control the partitioning of work and reproduction 2 and 4 . Here, we show that unrelated founding queens of the ant Pachycondyla villosa use chemical cues to recognize each other...... perception, was prevented and in tests with anaesthetized queens. The cuticular chemical profiles of queens were neither associated with dominance nor fertility and, therefore, do not represent status badges 5 and 6 , and nestmate queens did not share a common odor. Personal recognition facilitates...

  4. Alex McQueen : power

    Index Scriptorium Estoniae

    1998-01-01

    A. McQueeni moevälisest tegevusest. 'American Express' tellis temalt krediitkaardi kujunduse. 1998. a. suvest ajakirja 'Dazed & Confused' abitoimetaja. A. McQueen on lubanud olla Björki (Island) video kunstiline juht.

  5. Highly Loaded Carbon Black Supported Pt Catalysts for Fuel Cells

    Czech Academy of Sciences Publication Activity Database

    Kaluža, Luděk; Larsen, M.J.; Zdražil, Miroslav; Gulková, Daniela; Vít, Zdeněk; Šolcová, Olga; Soukup, Karel; Koštejn, Martin; Bonde, J.L.; Maixnerová, Lucie; Odgaard, M.

    2015-01-01

    Roč. 256, NOV 1 (2015), s. 375-383 ISSN 0920-5861 R&D Projects: GA MŠk(CZ) 7HX13003 EU Projects: European Commission(XE) 303466 - IMMEDIATE Institutional support: RVO:67985858 Keywords : carbon black * fuell cell * electrocatalyst Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 4.312, year: 2015

  6. Sulfonated carbon black-based composite membranes for fuel cell ...

    Indian Academy of Sciences (India)

    Sci., Vol. 36, No. 4, August 2013, pp. 563–573. c Indian Academy of Sciences. Sulfonated carbon black-based composite membranes for fuel cell applications .... All data were collected from a second heating cycle and glass tran- sition temperatures (Tg) were calculated as a midpoint of thermogram. 2.5d FTIR studies: FTIR ...

  7. New insights into honey bee (Apis mellifera pheromone communication. Is the queen mandibular pheromone alone in colony regulation?

    Directory of Open Access Journals (Sweden)

    Plettner Erika

    2010-06-01

    Full Text Available Abstract Background In social insects, the queen is essential to the functioning and homeostasis of the colony. This influence has been demonstrated to be mediated through pheromone communication. However, the only social insect for which any queen pheromone has been identified is the honey bee (Apis mellifera with its well-known queen mandibular pheromone (QMP. Although pleiotropic effects on colony regulation are accredited to the QMP, this pheromone does not trigger the full behavioral and physiological response observed in the presence of the queen, suggesting the presence of additional compounds. We tested the hypothesis of a pheromone redundancy in honey bee queens by comparing the influence of queens with and without mandibular glands on worker behavior and physiology. Results Demandibulated queens had no detectable (E-9-oxodec-2-enoic acid (9-ODA, the major compound in QMP, yet they controlled worker behavior (cell construction and queen retinue and physiology (ovary inhibition as efficiently as intact queens. Conclusions We demonstrated that the queen uses other pheromones as powerful as QMP to control the colony. It follows that queens appear to have multiple active compounds with similar functions in the colony (pheromone redundancy. Our findings support two hypotheses in the biology of social insects: (1 that multiple semiochemicals with synonymous meaning exist in the honey bee, (2 that this extensive semiochemical vocabulary exists because it confers an evolutionary advantage to the colony.

  8. Genetic reincarnation of workers as queens in the Eastern honeybee Apis cerana.

    Science.gov (United States)

    Holmes, M J; Tan, K; Wang, Z; Oldroyd, B P; Beekman, M

    2015-01-01

    Thelytokous parthenogenesis, or the asexual production of female offspring, is rare in the animal kingdom, but relatively common in social Hymenoptera. However, in honeybees, it is only known to be ubiquitous in one subspecies of Apis mellifera, the Cape honeybee, A. mellifera capensis. Here we report the appearance of queen cells in two colonies of the Eastern honeybee Apis cerana that no longer contained a queen or queen-produced brood to rear queens from. A combination of microsatellite genotyping and the timing of the appearance of these individuals excluded the possibility that they had been laid by the original queen. Based on the genotypes of these individuals, thelytokous production by natal workers is the most parsimonious explanation for their existence. Thus, we present the first example of thelytoky in a honeybee outside A. mellifera. We discuss the evolutionary and ecological consequences of thelytoky in A. cerana, in particular the role thelytoky may play in the recent invasions by populations of this species.

  9. A distinct role of the queen in coordinated workload and soil distribution in eusocial naked mole-rats.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kutsukake

    Full Text Available We investigated how group members achieve collective decision-making, by considering individual intrinsic behavioural rules and behavioural mechanisms for maintaining social integration. Using a simulated burrow environment, we investigated the behavioural rules of coordinated workload for soil distribution in a eusocial mammal, the naked mole-rat (Heterocephalus glaber. We tested two predictions regarding a distinct role of the queen, a socially dominant individual in the caste system: the presence of a queen would increase the workload of other caste individuals, and the cues by a queen would affect the soil distribution. In experiment 1, we placed four individuals of various castes from the same colony into an experimental burrow. Workers exhibited the highest frequency of workload compared to other castes. The presence of a queen activated the workload by other individuals. Individuals showed a consistent workload in a particular direction so as to bias the soil distribution. These results suggest that individuals have a consensus on soil distribution and that the queen plays a distinct role. In experiment 2, we placed the odour of a queen in one of four cells and observed its effect on other individuals' workload and soil distribution. Relative to other cells, individuals frequently dug in the queen cell so the amount of soil in the queen cell decreased. These results suggest that queen odour is an important cue in coordinated workload and soil distribution in this species.

  10. Differences in mushroom bodies morphogenesis in workers, queens and drones of Apis mellifera: neuroblasts proliferation and death.

    Science.gov (United States)

    Roat, Thaisa Cristina; da Cruz Landim, Carminda

    2010-06-01

    Apis mellifera is an interesting model to neurobiological studies. It has a relatively small brain that commands the complex learning and memory tasks demanded by the social organization. An A. mellifera colony is made up of a queen, thousands of workers and a varying number of drones. The latter are males, whereas the former are the two female castes. These three phenotypes differ in morphology, physiology and behavior, correlated with their respective functions in the society. Such differences include the morphology and architecture of their brains. To understand the processes generating such polymorphic brains we characterized the cell division and cell death dynamics which underlie the morphogenesis of the mushroom bodies, through several methods suitable for evidence the time and place of occurrence. Cell death was detected in mushroom bodies of last larval instar and mainly in black-eyed pupae. Cell division was observed in mushroom bodies, primarily at the start of metamorphosis, exhibiting temporal differences among workers, queens and males. Copyright 2010 Elsevier Ltd. All rights reserved.

  11. Chronic Bee Paralysis Virus in Honeybee Queens

    DEFF Research Database (Denmark)

    Amiri, Esmaeil; Meixner, Marina; Büchler, Ralph

    2014-01-01

    Chronic bee paralysis virus (CBPV) is known as a disease of worker honey bees. To investigate pathogenesis of the CBPV on the queen, the sole reproductive individual in a colony, we conducted experiments regarding the susceptibility of queens to CBPV. Results from susceptibility experiment showed...... a similar disease progress in the queens compared to worker bees after infection. Infected queens exhibit symptoms by Day 6 post infection and virus levels reach 1011 copies per head. In a transmission experiment we showed that social interactions may affect the disease progression. Queens with forced...... contact to symptomatic worker bees acquired an overt infection with up to 1011 virus copies per head in six days. In contrast, queens in contact with symptomatic worker bees, but with a chance to receive food from healthy bees outside the cage appeared healthy. The virus loads did not exceed 107...

  12. Dispersal behavior of yellowjacket (Vespula germanica) queens.

    Science.gov (United States)

    Masciocchi, Maité; Martinez, Andrés S; Pereira, Ana J; Villacide, José M; Corley, Juan C

    2018-02-01

    Understanding the factors that affect animal dispersal behavior is important from both fundamental and applied perspectives. Dispersal can have clear evolutionary and ecological consequences, but for nonnative insect pests, dispersal capacity can also help to explain invasion success. Vespula germanica is a social wasp that, in the last century, has successfully invaded several regions of the world, showing one of the highest spread rates reported for a nonnative insect. In contrast with nonsocial wasps, in social species, queens are responsible for population redistribution and spread, as workers are sterile. For V. germanica, it has been observed that queen flight is limited to 2 distinct periods: early autumn, when new queens leave the nest to mate and find sheltered places in which to hibernate, and spring when new colonies are founded. Our aim was to study the flight behavior of V. germanica queens by focusing on the different periods in which dispersal occurs, characterizing as well the potential contribution of queen flight (i.e., distance) to the observed geographical spread. Our results suggest that the distances flown by nonoverwintered queens is greater than that flown by overwintered individuals, suggesting that the main queen dispersal events would occur before queens enter hibernation. This could relate to a behavioral trait of the queens to avoid the inbreeding with related drones. Additionally, given the short distances flown and remarkable geographical spread observed, we provide evidence showing that queen dispersal by flight is likely to contribute proportionately less to population spread than human-aided factors. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  13. Comparing alternative methods for holding virgin honey bee queens for one week in mailing cages before mating.

    Science.gov (United States)

    Bigio, Gianluigi; Grüter, Christoph; Ratnieks, Francis L W

    2012-01-01

    In beekeeping, queen honey bees are often temporarily kept alive in cages. We determined the survival of newly-emerged virgin honey bee queens every day for seven days in an experiment that simultaneously investigated three factors: queen cage type (wooden three-hole or plastic), attendant workers (present or absent) and food type (sugar candy, honey, or both). Ten queens were tested in each of the 12 combinations. Queens were reared using standard beekeeping methods (Doolittle/grafting) and emerged from their cells into vials held in an incubator at 34C. All 12 combinations gave high survival (90 or 100%) for three days but only one method (wooden cage, with attendants, honey) gave 100% survival to day seven. Factors affecting queen survival were analysed. Across all combinations, attendant bees significantly increased survival (18% vs. 53%, p<0.001). In addition, there was an interaction between food type and cage type (p<0.001) with the honey and plastic cage combination giving reduced survival. An additional group of queens was reared and held for seven days using the best method, and then directly introduced using smoke into queenless nucleus colonies that had been dequeened five days previously. Acceptance was high (80%, 8/10) showing that this combination is also suitable for preparing queens for introduction into colonies. Having a simple method for keeping newly-emerged virgin queens alive in cages for one week and acceptable for introduction into queenless colonies will be useful in honey bee breeding. In particular, it facilitates the screening of many queens for genetic or phenotypic characteristics when only a small proportion meets the desired criteria. These can then be introduced into queenless hives for natural mating or insemination, both of which take place when queens are one week old.

  14. Comparing alternative methods for holding virgin honey bee queens for one week in mailing cages before mating.

    Directory of Open Access Journals (Sweden)

    Gianluigi Bigio

    Full Text Available In beekeeping, queen honey bees are often temporarily kept alive in cages. We determined the survival of newly-emerged virgin honey bee queens every day for seven days in an experiment that simultaneously investigated three factors: queen cage type (wooden three-hole or plastic, attendant workers (present or absent and food type (sugar candy, honey, or both. Ten queens were tested in each of the 12 combinations. Queens were reared using standard beekeeping methods (Doolittle/grafting and emerged from their cells into vials held in an incubator at 34C. All 12 combinations gave high survival (90 or 100% for three days but only one method (wooden cage, with attendants, honey gave 100% survival to day seven. Factors affecting queen survival were analysed. Across all combinations, attendant bees significantly increased survival (18% vs. 53%, p<0.001. In addition, there was an interaction between food type and cage type (p<0.001 with the honey and plastic cage combination giving reduced survival. An additional group of queens was reared and held for seven days using the best method, and then directly introduced using smoke into queenless nucleus colonies that had been dequeened five days previously. Acceptance was high (80%, 8/10 showing that this combination is also suitable for preparing queens for introduction into colonies. Having a simple method for keeping newly-emerged virgin queens alive in cages for one week and acceptable for introduction into queenless colonies will be useful in honey bee breeding. In particular, it facilitates the screening of many queens for genetic or phenotypic characteristics when only a small proportion meets the desired criteria. These can then be introduced into queenless hives for natural mating or insemination, both of which take place when queens are one week old.

  15. Sperm use economy of honeybee (Apis mellifera) queens

    DEFF Research Database (Denmark)

    Baer, Boris; Collins, Jason; Maalaps, Kristiina

    2016-01-01

    the fecundity and longevity of queens and therefore colony fitness. We quantified the number of sperm that honeybee (Apis mellifera) queens use to fertilize eggs. We examined sperm use in naturally mated queens of different ages and in queens artificially inseminated with different volumes of semen. We found...

  16. Stimulating natural supersedure of honeybee queens, Apis mellifera

    NARCIS (Netherlands)

    Hendriksma, H.P.; Calis, J.N.M.; Boot, W.J.

    2004-01-01

    When a honeybee queen starts to fail, she is often superseded by a young queen that takes over reproduction inside the colony. Natural supersedure in winter leads to an unfertilised young queen and colony loss. To reduce these losses we tried to stimulate supersedure of queens earlier in the season.

  17. Queen's discovery lauded by top scientific journal

    CERN Multimedia

    McGrady, S

    2002-01-01

    A scientific breakthrough at Queen's University's Sudbury Neutrino Observatory has received major international recognition. The journal Science ranked the discovery that cracked the "neutrino problem" second, in the journal's top 10 scientific achievements of 2002 (1/2 page).

  18. ECONOMIC EFFICIENCY OF VARIOUS QUEEN BEES MAINTENANCE SYSTEMS

    Directory of Open Access Journals (Sweden)

    A POPESCU

    2003-10-01

    Full Text Available The modern queens maintenance systems are based on the use of artificial insemination, queens’ maintenance in the so called „queens bank” , in this way assuring an increased economic efficiency in beekeeping. This study aimed to compare the economic efficiency of the implementation of A.I. to various queen bees maintenance systems. Three alternatives have been taken into account: V1-a queen bee in a cage together with her bees, V2- a queen bank system and V3 – a queen bee in a nucleus. For each queen bee maintenance alternative have been evaluated the most important indicators such as: expenses, incomes, profit, number of marketable inseminated and selected queen bees, honey production, cost/queen, revenue/queen, profit/queen, profit rate. The most effective alternative was the queen bank system assuring 2,400 marketable queen bees and 20 kg honey delivered yearly, USD 12,442 incomes, USD 3,400 expenses, USD 9,042 profit, that is USD 3.77/queen bee and 265.72 % profit rate under the condition as A.I. costs are just USD 1,058, representing 31.1 % of total queen bees maintenance costs.

  19. Black cohosh inhibits 17β-estradiol-induced cell proliferation of endometrial adenocarcinoma cells.

    Science.gov (United States)

    Park, So Yun; Kim, Hee Ja; Lee, Sa Ra; Choi, Youn-Hee; Jeong, Kyungah; Chung, Hyewon

    2016-10-01

    This study was conducted to investigate the effect of black cohosh (BC) extract on the proliferation and apoptosis of Ishikawa cells. Ishikawa human endometrial adenocarcinoma cells were treated with or without BC (1, 5, 10 and 25 μM) and cell proliferation and cytotoxicity were measured by CCK-8 assays and flow cytometry analysis. Additionally, Ishikawa cells were treated with 17β-estradiol (E2), E2 + progesterone and E2 + BC (5 and 10 μM) and the effect of BC and progesterone on E2-induced cell proliferation was analyzed. BC decreased the proliferation of Ishikawa cells at a dose-dependent rate compared with the control group (p < 0.05). The proliferation of Ishikawa cells increased in the presence of E2, whereas the subsequent addition of progesterone or BC decreased proliferation to the level of the control group (p < 0.05). The inhibitory effect of BC on E2-induced cell proliferation was greater than the inhibitory effect of progesterone. In conclusion, BC induces apoptosis in Ishikawa cells and suppresses E2-induced cell proliferation in Ishikawa cells. BC could be considered a candidate co-treatment agent of estrogen-dependent tumors, especially those involving endometrial cells.

  20. Stirred cell ultrafiltration of lignin from black liquor generated from South African kraft mills

    CSIR Research Space (South Africa)

    Kekana, Paul

    2016-12-01

    Full Text Available Ultrafiltration of lignin from black liquor was carried out in a stirred batch cell using polyethersulfone membranes. Parameters such as operating pressure, feed concentration, stirring rate and membrane cut-off size were varied and their effects...

  1. Honey Bee (Apis mellifera Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response.

    Directory of Open Access Journals (Sweden)

    Juliana Rangel

    Full Text Available Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera, with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of "high-quality" queens (i.e., raised from first instar worker larvae; more queen-like and "low-quality" queens (i.e., raised from third instar worker larvae; more worker-like. We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone ("QMP" components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the "queen-specific" developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting

  2. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response.

    Science.gov (United States)

    Rangel, Juliana; Böröczky, Katalin; Schal, Coby; Tarpy, David R

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of "high-quality" queens (i.e., raised from first instar worker larvae; more queen-like) and "low-quality" queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone ("QMP") components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the "queen-specific" developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting that other external

  3. Raman imaging of lignin and cellulose distribution in black spruce wood (Picea mariana) cell walls

    Science.gov (United States)

    Umesh P. Agarwal

    2005-01-01

    A detailed understanding of wood cell wall structure and organization is important from both fundamental and practical point of views. A state-of- the-art 633-nm laser based confocal Raman microscope was used in situ to investigate the cell wall organization of black spruce wood. Chemical information on lignin and cellulose from morphologically distinct cell wall...

  4. Queen introduction into the queenright honey bee colony

    Directory of Open Access Journals (Sweden)

    Antonín Přidal

    2010-01-01

    Full Text Available One of the actual elementary biologic principles of the introduction of queen is that the recipient co­lo­ny has to be queenless. We accidentally found that a queen can be accepted also in queenright co­lo­ny with using of the queen excluder. Therefore, we conducted two experiments with the introduction of queen in queenright colony.Under defined conditions of the experiment and with application of the queen excluder as a separator of queens we successfully introduced queen in the queenright colony. This result is discussed in relation to the general principle that a queen should be introduced only in a queenless colony. It is possible that there are some exceptions advert to the existence of some unknown biologic patterns in the honey bee biology and pheromones.

  5. Effects of insemination quantity on honey bee queen physiology.

    Directory of Open Access Journals (Sweden)

    Freddie-Jeanne Richard

    2007-10-01

    Full Text Available Mating has profound effects on the physiology and behavior of female insects, and in honey bee (Apis mellifera queens, these changes are permanent. Queens mate with multiple males during a brief period in their early adult lives, and shortly thereafter they initiate egg-laying. Furthermore, the pheromone profiles of mated queens differ from those of virgins, and these pheromones regulate many different aspects of worker behavior and colony organization. While it is clear that mating causes dramatic changes in queens, it is unclear if mating number has more subtle effects on queen physiology or queen-worker interactions; indeed, the effect of multiple matings on female insect physiology has not been broadly addressed. Because it is not possible to control the natural mating behavior of queens, we used instrumental insemination and compared queens inseminated with semen from either a single drone (single-drone inseminated, or SDI or 10 drones (multi-drone inseminated, or MDI. We used observation hives to monitor attraction of workers to SDI or MDI queens in colonies, and cage studies to monitor the attraction of workers to virgin, SDI, and MDI queen mandibular gland extracts (the main source of queen pheromone. The chemical profiles of the mandibular glands of virgin, SDI, and MDI queens were characterized using GC-MS. Finally, we measured brain expression levels in SDI and MDI queens of a gene associated with phototaxis in worker honey bees (Amfor. Here, we demonstrate for the first time that insemination quantity significantly affects mandibular gland chemical profiles, queen-worker interactions, and brain gene expression. Further research will be necessary to elucidate the mechanistic bases for these effects: insemination volume, sperm and seminal protein quantity, and genetic diversity of the sperm may all be important factors contributing to this profound change in honey bee queen physiology, queen behavior, and social interactions in the

  6. Sulfonated carbon black-based composite membranes for fuel cell ...

    Indian Academy of Sciences (India)

    C/min under nitrogen atmosphere. All data were collected from a second heating cycle and glass tran- sition temperatures (Tg) were calculated as a midpoint of thermogram. 2.5d FTIR studies: FTIR spectra were recorded for mem- branes using Perkin Elmer Pyris 1 FTIR spectrophoto- meter. Membrane and carbon black ...

  7. Effect of age of honeybee queens of Apis mellifera adansonii ...

    African Journals Online (AJOL)

    The effect of age of honeybee queens of Apis mellifera adansonii on rate of brood production was studied using Langstroth hives. Brood productivity of young queens (24 days old) and old queens (18 months old) was investigated and compared by extrapolating the brood areas covered as equivalent to the number of eggs ...

  8. Cell motility, morphology, viability and proliferation in response to nanotopography on silicon black.

    NARCIS (Netherlands)

    Łopacińska, Joanna M; Grǎdinaru, Cristian; Wierzbicki, Rafal; Købler, Carsten; Schmidt, Michael S; Madsen, Martin T; Skolimowski, Maciej; Dufva, Martin; Flyvbjerg, Henrik; Mølhave, Kristian

    2012-01-01

    Knowledge of cells' interactions with nanostructured materials is fundamental for bio-nanotechnology. We present results for how individual mouse fibroblasts from cell line NIH3T3 respond to highly spiked surfaces of silicon black that were fabricated by maskless reactive ion etching (RIE). We did

  9. Higher acid-chlorite reactivity of cell corner middle lamella lignin in black spruce

    Science.gov (United States)

    Umesh P. Agarwal

    2007-01-01

    To determine if there was a delignification behavior difference between secondary wall (S2) and middle lamella (cell corner or CC) lignin, black spruce cross-sections were acid-chlorite delignified and the tissue was evaluated in-situ by Raman imaging. Lignin concentration in S2 and CC was determined in numerous latewood cell areas in the two hour delignified cross...

  10. The effect of queen and worker adoption on weaver ant (Oecophylla smaragdina) queen fecundity

    DEFF Research Database (Denmark)

    Offenberg, Joachim; Peng, Renkang; Nielsen, Mogens Gissel

    2012-01-01

    Incipient ant colonies are often under fierce competition, making fast growth crucial for survival. To increase production, colonies can adopt multiple queens (pleometrosis), fuse with other colonies or rob brood from neighboring colonies. However, different adoption strategies might have different...

  11. Ant parasite queens revert to mating singly

    DEFF Research Database (Denmark)

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe

    2004-01-01

    A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easi...

  12. Women in History--Queen Liliuokalani

    Science.gov (United States)

    Koeppe, Tina

    2007-01-01

    This article profiles Queen Liliuokalani, Hawaii's last monarch. Liliuokalani was born in Hawaii in 1838 into the family of a high chief. She attended the Royal School, run by American missionaries, and received a high quality education and learned to love music, writing and politics. Liliuokalani was given the Christian name "Lydia" as…

  13. Queen volatiles as a modulator of Tetragonisca angustula drone behavior.

    Science.gov (United States)

    Fierro, Macario M; Cruz-López, Leopoldo; Sánchez, Daniel; Villanueva-Gutiérrez, Rogel; Vandame, Remy

    2011-11-01

    Tetragonisca angustula mating occurs during the virgin queen nuptial flight, usually in the presence of a drone congregation area (DCA). The presence of virgin queen pheromone is considered the trigger for DCA establishment, although this has not been demonstrated experimentally. We established meliponaries, in different habitats, with T. angustula virgin queens during the main drone reproduction period. Eight DCAs were observed in urban areas, and all established outside or near colonies containing at least one virgin queen. The accumulation of drones in the DCAs occurred from 08:00 to 18:00 h and over 3-35 days. The number of drones in DCAs ranged from 60 to 2,000. In field trials, drones were attracted to virgin queens and also, unexpectedly, to physogastric queens. Volatiles collected from both virgin and physogastric queens elicited strong electoantennogram (EAG) responses from drones. Virgin and physogastric queen volatiles were qualitatively similar, but quantitatively different, in chemical composition. The queen's abdomen was the principal source of these compounds. Isopropyl hexanoate (IPH), the most abundant compound in virgin queen volatiles and one of the most abundant in physogastric queen volatiles, was identified as one of the compounds that elicited EAG responses and was demonstrated to attract drones in a field test.

  14. Immune priming and pathogen resistance in ant queens.

    Science.gov (United States)

    Gálvez, Dumas; Chapuisat, Michel

    2014-05-01

    Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring.

  15. Immunosuppression in Honeybee Queens by the Neonicotinoids Thiacloprid and Clothianidin.

    Science.gov (United States)

    Brandt, Annely; Grikscheit, Katharina; Siede, Reinhold; Grosse, Robert; Meixner, Marina Doris; Büchler, Ralph

    2017-07-05

    Queen health is crucial to colony survival of honeybees, since reproduction and colony growth rely solely on the queen. Queen failure is considered a relevant cause of colony losses, yet few data exist concerning effects of environmental stressors on queens. Here we demonstrate for the first time that exposure to field-realistic concentrations of neonicotinoid pesticides can severely affect the immunocompetence of queens of western honeybees (Apis mellifera L.). In young queens exposed to thiacloprid (200 µg/l or 2000 µg/l) or clothianidin (10 µg/l or 50 µg/l), the total hemocyte number and the proportion of active, differentiated hemocytes was significantly reduced. Moreover, functional aspects of the immune defence namely the wound healing/melanisation response, as well as the antimicrobial activity of the hemolymph were impaired. Our results demonstrate that neonicotinoid insecticides can negatively affect the immunocompetence of queens, possibly leading to an impaired disease resistance capacity.

  16. Carbon black nanoparticles induce type II epithelial cells to release chemotaxins for alveolar macrophages

    Directory of Open Access Journals (Sweden)

    Donaldson Ken

    2005-12-01

    Full Text Available Abstract Background Alveolar macrophages are a key cell in dealing with particles deposited in the lungs and in determining the subsequent response to that particle exposure. Nanoparticles are considered a potential threat to the lungs and the mechanism of pulmonary response to nanoparticles is currently under intense scrutiny. The type II alveolar epithelial cell has previously been shown to release chemoattractants which can recruit alveolar macrophages to sites of particle deposition. The aim of this study was to assess the responses of a type II epithelial cell line (L-2 to both fine and nanoparticle exposure in terms of secretion of chemotactic substances capable of inducing macrophage migration. Results Exposure of type II cells to carbon black nanoparticles resulted in significant release of macrophage chemoattractant compared to the negative control and to other dusts tested (fine carbon black and TiO2 and nanoparticle TiO2 as measured by macrophage migration towards type II cell conditioned medium. SDS-PAGE analysis of the conditioned medium from particle treated type II cells revealed that a higher number of protein bands were present in the conditioned medium obtained from type II cells treated with nanoparticle carbon black compared to other dusts tested. Size-fractionation of the chemotaxin-rich supernatant determined that the chemoattractants released from the epithelial cells were between 5 and 30 kDa in size. Conclusion The highly toxic nature and reactive surface chemistry of the carbon black nanoparticles has very likely induced the type II cell line to release pro-inflammatory mediators that can potentially induce migration of macrophages. This could aid in the rapid recruitment of inflammatory cells to sites of particle deposition and the subsequent removal of the particles by phagocytic cells such as macrophages and neutrophils. Future studies in this area could focus on the exact identity of the substance(s released by the

  17. Cell motility, morphology, viability and proliferation in response to nanotopography on silicon black

    DEFF Research Database (Denmark)

    Lopacinska, Joanna M.; Gradinaru, Cristian; Wierzbicki, Rafal

    2012-01-01

    Knowledge of cells' interactions with nanostructured materials is fundamental for bio-nanotechnology. We present results for how individual mouse fibroblasts from cell line NIH3T3 respond to highly spiked surfaces of silicon black that were fabricated by maskless reactive ion etching (RIE). We did...... standard measurements of cell viability, proliferation, and morphology on various surfaces. We also analyzed the motility of cells on the same surfaces, as recorded in time lapse movies of sparsely populated cell cultures. We find that motility and morphology vary strongly with nano-patterns, while...

  18. Queen pheromones in Temnothorax ants: control or honest signal?

    Directory of Open Access Journals (Sweden)

    Kroiss Johannes

    2011-03-01

    Full Text Available Abstract Background The division of reproductive labor among group members in insect societies is regulated by "queen pheromones". However, it remains controversial whether these are manipulative, i.e., actively suppress worker reproduction, or honestly signal the fertility status of the queen to which workers react in their own interest by refraining from laying eggs. Manipulative queen control is thought to lead to an evolutionary arms race between queens and workers, resulting in complex queen bouquets that diverge strongly among different populations and species. In contrast, honest signals would evolve more slowly and might therefore differ less strongly within and among species. Results We aimed at determining the tempo of the evolution of queen signals in two ways. First, we investigated whether queens of Temnothorax ants are capable of controlling egg laying by workers of their own, closely, and distantly related species. Second, we compared the species- and caste-specific patterns of cuticular hydrocarbons, which are assumed to convey information on reproductive status. In mixed-species colonies, queens were not able to fully suppress egg-laying and male production by workers of unrelated species, while workers did not reproduce under the influence of a queen from their own species. Furthermore, the chemical profiles differed more strongly among queens of different species than among the respective workers. Conclusions Our results suggest that cuticular hydrocarbons associated with fecundity are not fully conserved in evolution and evolve slightly faster than worker-specific components in the blend of cuticular hydrocarbons. While this higher rate of evolution might reflect an arms race between queens and workers, the observation that workers still respond to the presence of a queen from another species support the honest signal hypothesis. Future studies need to examine alternative explanations for a higher rate of evolution of queen

  19. Does whole-cell pertussis vaccine protect black South African infants?

    African Journals Online (AJOL)

    The whole-cell pertussis vaccine currently used in South Africa has not been adequately evaluated for post-vaccination events and immunogenicity. A trial of this vaccine combined with diphtheria and tetanus toxoids (DTP) was undertaken in 115 black babies who received primary vaccination at 2, 4 and 6 months of age.

  20. Cytotoxic and apoptotic activities of black widow spiderling extract against HeLa cells.

    Science.gov (United States)

    Peng, Xiaozhen; Dai, Zhipan; Lei, Qian; Liang, Long; Yan, Shuai; Wang, Xianchun

    2017-06-01

    Black widow spiders contain toxic components not only in the venom glands but also in other parts of the spider body, including the legs and abdomen. Additionally, both the eggs and newborn spiderlings of the black widow spider contain venom. It is important to investigate their potential effects on cancer cells. In the present study, the effects of newborn black widow spiderling extract on human HeLa cells were evaluated in vitro . When applied at different concentrations, the total extract decreased HeLa cell viability in a dose-dependent manner, with an IC 50 value of 158 µg/ml. Flow cytometry indicated that treatment of HeLa cells with the total extract of the spiderlings induced apoptosis in HeLa cells in a dose-dependent manner and led to cell cycle arrest in the S-phase. Additionally, application of the total extract at different concentrations increased apoptosis-related caspase 3 activity in a dose-dependent manner. HeLa cells treated with the total extract appeared to be morphologically changed, exhibiting membrane blebbing, nuclear fragmentation and condensation of chromatin. Further separation and activity screening demonstrated that the cytotoxic and apoptotic activities of the total extract were attributable mainly to its high molecular mass proteins, one of which was purified and characterized to determine its anti-tumor activities on HeLa cells. The results of the present study therefore have expanded understanding regarding the effect of spider toxins on cancer cells and suggested that components of black widow spiderlings may be developed as a promising novel agent to treat cancer.

  1. Surface passivation of efficient nanotextured black silicon solar cells using thermal atomic layer deposition.

    Science.gov (United States)

    Wang, Wei-Cheng; Lin, Che-Wei; Chen, Hsin-Jui; Chang, Che-Wei; Huang, Jhih-Jie; Yang, Ming-Jui; Tjahjono, Budi; Huang, Jian-Jia; Hsu, Wen-Ching; Chen, Miin-Jang

    2013-10-09

    Efficient nanotextured black silicon solar cells passivated by an Al2O3 layer are demonstrated. The broadband antireflection of the nanotextured black silicon solar cells was provided by fabricating vertically aligned silicon nanowire (SiNW) arrays on the n(+) emitter. A highly conformal Al2O3 layer was deposited upon the SiNW arrays by the thermal atomic layer deposition (ALD) based on the multiple pulses scheme. The nanotextured black silicon wafer covered with the Al2O3 layer exhibited a low total reflectance of ∼1.5% in a broad spectrum from 400 to 800 nm. The Al2O3 passivation layer also contributes to the suppressed surface recombination, which was explored in terms of the chemical and field-effect passivation effects. An 8% increment of short-circuit current density and 10.3% enhancement of efficiency were achieved due to the ALD Al2O3 surface passivation and forming gas annealing. A high efficiency up to 18.2% was realized in the ALD Al2O3-passivated nanotextured black silicon solar cells.

  2. The evolution of honest queen pheromones in insect societies

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn

    2010-01-01

    of their ovaries and by preventing other workers from reproducing (worker policing). However, what maintains the honesty of such queen pheromones is still under discussion. The explanation that an honest queen signal evolves simply because it serves the interest of all colony members does not seem to hold, since...... it is undermined by the fitness benefits of direct reproduction of workers at the individual level. A better explanation may be found in the idea that queen pheromones are difficult to produce for subordinate individuals, either because policing workers attack them, or because queen pheromones are intrinsically...

  3. Sulfonated carbon black-based composite membranes for fuel cell ...

    Indian Academy of Sciences (India)

    Pristine and composite membranes prepared from SPEEK82 decomposed completely in <1 h, which is undesirable for fuel cell applications. SPEEK60 membrane having wt% of 0.25–0.5 with S–C particles led to higher proton conductivity than that of pristine membrane. No positive effect was observed on the properties of ...

  4. Blastic Plasmacytoid Dendritic Cell Leukemia in a Black Malian

    African Journals Online (AJOL)

    2017-06-28

    Jun 28, 2017 ... (BPDCN) is an acute myeloblastic leukemia (AML) characterized by the clonal proliferation of precursors of plasmacytoid dendritic cells. It is categorized as an acute myeloid neoplasm by the 2008 world health organization classification of neoplasms. Over 90% of cases present with skin lesions in the form ...

  5. 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.

  6. In vitro cytotoxicity of carbon black nanoparticles synthesized from solution plasma on human lung fibroblast cells

    Science.gov (United States)

    Panomsuwan, Gasidit; Chokradjaroen, Chayanaphat; Rujiravanit, Ratana; Ueno, Tomonaga; Saito, Nagahiro

    2018-01-01

    Carbon black nanoparticles (CB-NPs) have been synthesized from liquid benzene by a solution plasma method at room temperature and atmospheric pressure. The morphological observation by scanning electron microscopy revealed the agglomeration of aggregated fine particles. The synthesized CB-NPs were predominantly amorphous as confirmed by X-ray diffraction. The in vitro cytotoxicity of CB-NPs on the human lung fibroblast (MRC-5) cell line was assessed by the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and systematically compared with those of two types of commercial carbon blacks (i.e., Vulcan XC-72 and Ketjenblack EC-600JD). Cell viabilities were studied at different concentrations of 32.5, 65, 125, and 250 µg/mL. It was found that the CB-NPs derived from solution plasma exhibited a lower cytotoxicity on the MRC-5 cells than the other two comparative carbon blacks. The viability of MRC-5 cells exposed to CB-NPs remained higher than 90% even at a high concentration of 250 µg/mL. This result preliminarily confirmed the biosafety and potential use of CB-NPs in the field of biological applications.

  7. Viral diseases in honey bee queens

    DEFF Research Database (Denmark)

    Francis, Roy Mathew

    Honey bees are important insects for human welfare, due to pollination as well as honey production. Viral diseases strongly impact honey bee health, especially since the spread of varroa mites. This dissertation deals with the interactions between honey bees, viruses and varroa mites. A new tool...... was developed to diagnose three viruses in honey bees. Quantitative PCR was used to investigate the distribution of two popular viruses in five different tissues of 86 honey bee queens. Seasonal variation of viral infection in honey bee workers and varroa mites were determined by sampling 23 colonies under...

  8. Fuel Cell Platinum Catalysts Supported on Mediate Surface Area Carbon Black Supports

    Czech Academy of Sciences Publication Activity Database

    Kaluža, Luděk; Larsen, M.J.; Zdražil, Miroslav; Gulková, Daniela; Odgaard, M.

    2015-01-01

    Roč. 43, č. 2015 (2015), s. 913-918 ISSN 1974-9791. [International Conference on Chemical and Process Engineering - ICheaP12 /12./. Milano, 19.05.2015-22.05.2015] R&D Projects: GA MŠk(CZ) 7HX13003 EU Projects: European Commission(XE) 303466 - IMMEDIATE Institutional support: RVO:67985858 Keywords : carbon black * platinum catalyst * fuel cell Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  9. Thermal conductivity and stability of nano size carbon black filled PDMS: Fuel cell perspective

    CSIR Research Space (South Africa)

    Chen, H

    2011-01-01

    Full Text Available resin-CB composites (with 70wt% loading). Keywords: Polydimethylsiloxane (PDMS); Polymer nanocomposite, Carbon black; Thermal conductivity; Thermal stability; Fuel cell Biographical notes: Hao Chen received his bachelor degree honours in physics... initiative (SANi), his current main research focus is related to smart and engineered nano-materials for photonics and renewable energy applications. Prof. V. Vasudeva Rao holds Bachelors Degree in Mechanical Engineering, Masters Degree...

  10. Effects of queen ages on Varroa (Varroa destructor infestation level in honey bee (Apis mellifera caucasica colonies and colony performance

    Directory of Open Access Journals (Sweden)

    Duran Özkök

    2010-01-01

    Full Text Available This study was conducted to determine the effects of queen age on varroa population levels in hives and performance of honey bee (A. mellifera caucasica colonies. Levels of varroa infestation and performances of the colonies which had 0, 1- and 2-year-old queens were compared in mild climate conditions. Varroa numbers on adults and drone brood, number of frames covered with bees and brood areas were determined every month between 10 May and 10 October 2004. Overall average (± S.E. % infestation levels of varroa were found to be 5.96 ± 1.42, 11.58 ± 1.46 and 15.87 ± 1.39% on adult bees and 21.55 ± 1.43, 31.96 ± 1.44 and 37.55 ± 1.45% in drone brood cells for 0, 1- and 2-year-old queen colonies, respectively. The colonies which had 0, 1- and 2-year-old queens produced 2673.58 ± 39.69, 2711.75 ± 39.68, and 1815.08 ± 39.70 cm2 overall average (± S.E. sealed brood and 10.35 ± 0.24, 10.43 ± 0.26 and 7.51 ± 0.21 numbers of frame adult bees, respectively. Honey harvested from 0, 1- and 2-year-old queen colonies averaged 21.60 ± 5.25, 22.20 ± 6.55, and 14.70 ± 2.50 kg/colony, respectively. The colonies headed by young queens had a lower level of varroa infestation, a greater brood area, longer worker bee population and greater honey yield in comparison to colonies headed by old queens.

  11. Presentation of child sexual abuse cases to Queen Elizabeth ...

    African Journals Online (AJOL)

    Aims To review child sexual abuse cases and their management presenting to Queen Elizabeth Central Hospital (QECH), Blantyre, since the introduction of an HIV post-exposure prophylaxis (PEP) programme. Methods Demographic and medical data was collected from all children presenting to Queen Elizabeth Central ...

  12. Sexual Cooperation: Mating Increases Longevity in Ant Queens

    DEFF Research Database (Denmark)

    Schrempf, Alexandra; Heinze, Jürgen; Cremer, Sylvia

    2005-01-01

    sterilized male lived considerably longer and started laying eggs earlier than virgin queens. Only queens that received viable sperm from fertile males showed increased fecundity. The lack of a trade-off between fecundity and longevity is unexpected, given evolutionary theories of aging [6] . Our data...

  13. Patterns of viral infection in honey bee queens

    DEFF Research Database (Denmark)

    Francis, Roy Mathew; Kryger, Per; Nielsen, Steen Lykke

    2013-01-01

    groups based on the level of infection in their head, thorax, ovary, intestines and spermatheca. Four queens exhibited egg-laying deficiency, but visually all queens appeared healthy. Viral infection was generally at a low level in terms of AKI copy numbers, with 134/430 tissues (31 %) showing...

  14. Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata).

    Science.gov (United States)

    Kottler, Verena A; Koch, Iris; Flötenmeyer, Matthias; Hashimoto, Hisashi; Weigel, Detlef; Dreyer, Christine

    2014-01-01

    The fitness of male guppies (Poecilia reticulata) highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.

  15. Structure of ovarioles in adult queens and workers of the common wasp, Vespula germanica (Hymenoptera: Vespidae).

    Science.gov (United States)

    Jabłońska, A; Biliński, S M

    2001-01-01

    The ovaries of the common wasp, Vespula germanica are polytrophic-meroistic and consist of 2-3 (workers) or 7 (queens) ovarioles. The ovarioles are differentiated into three regions: a terminal filament, a germarium, and a vitellarium. The germaria of both castes consist of two zones: an anterior zone of germ-cell cluster formation and a posterior one of germ-cell cluster differentiation. The vitellaria comprise 4-6 (workers) or 7-10 (queens) ovarian follicles (egg chambers). Each chamber consists of an oocyte and about 60 isodiametric nurse cells (trophocytes). The egg chambers have been arbitrarily classified into four developmental categories: early and late previtellogenic, vitellogenic, and choriogenic. The process of oogenesis in workers proceeds only up to the onset of the late previtellogenesis. Neither vitellogenic nor choriogenic egg chambers were observed in this caste. During early and late previtellogenesis the envelope of the oocyte nucleus proliferates and becomes highly folded. This process leads to the formation of characteristic organelles, termed accessory nuclei (AN). Although AN arise in the oocytes of both queens and workers, their number in the latter caste is always considerably lower. At the onset of the late previtellogenesis AN start to migrate towards the periphery of the oocyte where they reside till the end of oogenesis. The physiological state of the worker ovaries is discussed in the light of the presented results.

  16. Terapi Sel Punca Mesenkimal Sumsum Tulang Tikus dalam Meregenerasi Sel Sitotrofoblas Nekrosis yang Dipapar Carbon Black (RAT BONE MARROW MESENCHYMAL STEM CELL THERAPY IN REGENERATING NECROTIC CYTOTROPHOBLAST CELL FOLLOWING EXPOSED TO CARBON BLACK

    Directory of Open Access Journals (Sweden)

    Widjiati .

    2015-08-01

    Full Text Available The objective of this study is to find out the potency of Rat Bone Marrow Mesenchymal Stem Cell(RBMMSC in regenerating necrotic cytotrophoblast cells of rats (Rattusnorvegicus following exposure tocarbon black at day 6 of gestation at different time of exposure (6 days and 12 days. This study usedrandomized factorial design with two factors (gestation day and treatment. Forty-eight gravid femalerats were divided into six treatment groups i.e. (i animals at day 6-11 gestation and not expose to carbonblack; (ii 6-11 days gestation animals + 532mg/m3 carbon black for 4 hours; (iii 6-11 days gestationanimals + 532mg/m3 carbon black for 4 hours +1x107/0.1ml RBMMSC intravenously; (iv animals at day6-17 gestation and not expose to carbon black; (v 6-17 days gestation animals + 532mg/m3 carbon blackfor 4 hours; (vi 6-17 days gestation animals + 532mg/m3 carbon black for 4 hours +1x107/0.1ml RBMMSCintravenously, respectively. Data were analyzed using univariat analysis and analysis of variance. Theresults showed that there were no significance differences in regenerating necrotic cytotrophoblast betweenthe groups treated with RBMMSC and carbon black exposure. The results indicated that the stem celltherapy following exposure to carbon black was incapable in regenerating the necrotic cytotrophoblastcells.

  17. Are queen ants inhibited by their own pheromone?

    DEFF Research Database (Denmark)

    Holman, L.; Leroy, C.; Jørgensen, Charlotte

    2013-01-01

    . Communication in social insects is predominantly chemical, and the mechanisms regulating processes such as reproductive division of labor are becoming increasingly well understood. Recently, a queen cuticular hydrocarbon (3-MeC31) that inhibits worker reproduction and aggression was isolated in the ant Lasius...... niger. Here, we find that this pheromone also has a weak negative effect on queen productivity and oogenesis. Because 3-MeC31 is present on both queens and their brood, we suggest that it is used by ants of both castes to adjust their fecundity to the amount of developing brood and the presence of other...

  18. A contribution to queens graphs: A substitution method

    DEFF Research Database (Denmark)

    Ambrus, G.; Barat, Janos

    2006-01-01

    that the Cartesian product of an odd cycle and a path is a queens graph. We show that the same does not hold for two odd cycles. The representation of the Cartesian product of an odd cycle and an even cycle remains an open problem. We also prove constructively that any finite subgraph of the rectangular grid...... or the hexagonal grid is a queens graph. Using a small computer search we solve another conjecture of the authors mentioned above, saying that K-3,K-4 minus an edge is a minimal non-queens graph....

  19. Queen pheromones: The chemical crown governing insect social life

    DEFF Research Database (Denmark)

    Holman, Luke

    2010-01-01

    Group-living species produce signals that alter the behavior and even the physiology of their social partners. Social insects possess especially sophisticated chemical communication systems that govern every aspect of colony life, including the defining feature of eusociality: reproductive division...... of labor. Current evidence hints at the central importance of queen pheromones, but progress has been hindered by the fact that such pheromones have only been isolated in honeybees. In a pair of papers on the ant Lasius niger, we identified and investigated a queen pheromone regulating worker sterility...... with other studies, these results indicate that queen pheromones are honest signals of quality that simultaneously regulate multiple social behaviors....

  20. Nano-watt fueling from a micro-scale microbial fuel cell using black tea waste

    KAUST Repository

    Rojas, Jhonathan Prieto

    2016-02-03

    In this report, we show the rapid assessment of black tea as potential fuel to power up nanopower systems using a microsized, simplistic and sustainable air-cathode microbial fuel cell. It was found that tea produced more power compared with traditional sodium acetate media due in part to its acidophilic pH and its higher organics content. Although high internal resistance remains a big concern, this simple, curiosity-driven experiment gave us the preliminary results to say that energy could be extracted from the reuse of waste resources such the collection of our afternoon-tea\\'s leftovers.

  1. Evolutionary genetics of immunological supertypes reveals two faces of the Red Queen

    OpenAIRE

    Lighten, Jackie; Papadopulos, Alexander S. T.; Mohammed, Ryan S.; Ward, Ben J.; G. Paterson, Ian; Baillie, Lyndsey; Bradbury, Ian R.; Hendry, Andrew P.; Bentzen, Paul; van Oosterhout, Cock

    2017-01-01

    Red Queen host-parasite co-evolution can drive adaptations of immune-genes by positive selection that erodes genetic variation (Red Queen Arms Race), or result in a balanced polymorphism (Red Queen Dynamics) and the long-term preservation of genetic variation (trans-species polymorphism). These two Red Queen processes are opposite extremes of the co-evolutionary spectrum. Here we show that both Red Queen processes can operate simultaneously, analyzing the Major Histocompatibility Complex (MHC...

  2. Queen Size Variation in the Ponerine Ant Ponera coarctata (Hymenoptera: Formicidae

    Directory of Open Access Journals (Sweden)

    J. Liebig

    1995-01-01

    Full Text Available Queens of Ponera coarctata show a pronounced variation in size as measured by ommatidia number and Weber's alitrunk length. Isometric size variation and the normal distribution of size categories indicate that, despite these differences, only one queen morph exists. Queen size varies less within colonies than between colonies, and thus appears to be colony specific. Ovary length apparently varies with queen size. Similar size variations as in queens also occured in males, but not in workers.

  3. Social context predicts recognition systems in ant queens

    DEFF Research Database (Denmark)

    Dreier, Stéphanie Agnès Jeanine; d'Ettorre, Patrizia

    2009-01-01

    for dominance are costly; but it would not evolve in absence of hierarchies. We previously showed that Pachycondyla co-founding queens, which form dominance hierarchies, have accurate individual recognition based on chemical cues. Here, we used the ant Lasius niger to test the null hypothesis that individual...... recognition does not occur when co-founding queens do not establish dominance hierarchies. Indeed, L. niger queens show a similar level of aggression towards both co-foundresses and intruders, indicating that they are unable of individual recognition, contrary to Pachycondyla. Additionally, the variation...... in chemical profiles of Lasius and Pachycondyla queens is comparable, thus informational constraints are unlikely to apply. We conclude that selection pressure from the social context is of crucial significance for the sophistication of recognition systems....

  4. Recovery of Queen Conch in the U. S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The queen conch is an important cultural component and an extremely valuable coral reef fishery resource throughout the Caribbean, historically second only to the...

  5. Terminal investment: individual reproduction of ant queens increases with age.

    Directory of Open Access Journals (Sweden)

    Jürgen Heinze

    Full Text Available The pattern of age-specific fecundity is a key component of the life history of organisms and shapes their ecology and evolution. In numerous animals, including humans, reproductive performance decreases with age. Here, we demonstrate that some social insect queens exhibit the opposite pattern. Egg laying rates of Cardiocondyla obscurior ant queens increased with age until death, even when the number of workers caring for them was kept constant. Cardiocondyla, and probably also other ants, therefore resemble the few select organisms with similar age-specific reproductive investment, such as corals, sturgeons, or box turtles (e.g., [1], but they differ in being more short-lived and lacking individual, though not social, indeterminate growth. Furthermore, in contrast to most other organisms, in which average life span declines with increasing reproductive effort, queens with high egg laying rates survived as long as less fecund queens.

  6. Chaotic Red Queen coevolution in three-species food chains

    OpenAIRE

    Dercole, F.; Ferriere, R.; Rinaldi, S.

    2010-01-01

    Coevolution between two antagonistic species follows the so-called ‘Red Queen dynamics’ when reciprocal selection results in an endless series of adaptation by one species and counteradaptation by the other. Red Queen dynamics are ‘genetically driven’ when selective sweeps involving new beneficial mutations result in perpetual oscillations of the coevolving traits on the slow evolutionary time scale. Mathematical models have shown that a prey and a predator can coevolve along a genetically dr...

  7. The honeybee queen influences the regulation of colony drone production

    OpenAIRE

    Katie E. Wharton; Fred C. Dyer; Zachary Y. Huang; Thomas Getty

    2007-01-01

    Social insect colonies invest in reproduction and growth, but how colonies achieve an adaptive allocation to these life-history characters remains an open question in social insect biology. Attempts to understand how a colony's investment in reproduction is shaped by the queen and the workers have proved complicated because of the potential for queen--worker conflict over the colony's investment in males versus females. Honeybees, in which this conflict is expected to be minimal or absent, pr...

  8. Do sexist organizational cultures create the queen bee?

    OpenAIRE

    Derks, Belle; Ellemers, Naomi; van Laar, Colette; De Groot, Kim

    2011-01-01

    Queen Bees’ are senior women in masculine organizational cultures who have fulfilled their career aspirations by dissociating themselves from their gender while simultaneously contributing to the gender stereotyping of other women. It is often assumed that this phenomenon contributes to gender discrimination in organizations, and is inherent to the personalities of successful career women. We argue for a social identity explanation and examine organizational conditions that foster the Queen ...

  9. Pelaksanaan Bauran Promosi Objek Wisata Queen Star Waterpark Kabupaten Siak

    OpenAIRE

    Wardana, Tutut Dwi; ", Musadad

    2017-01-01

    The purpose of this research is to know the implementation of promotion mix conducted by Queen Star Waterpark management and to know the factors that influence the implementation of promotion mix in Queen Star Waterpark. This research uses descriptive qualitative method to analyze the problem. Data collection techniques in this study using interviews, observation and documentation. While data analysis techniques in this study using data reduction, data presentation and conclusion. Based on th...

  10. Chaotic Red Queen coevolution in three-species food chains.

    Science.gov (United States)

    Dercole, Fabio; Ferriere, Regis; Rinaldi, Sergio

    2010-08-07

    Coevolution between two antagonistic species follows the so-called 'Red Queen dynamics' when reciprocal selection results in an endless series of adaptation by one species and counteradaptation by the other. Red Queen dynamics are 'genetically driven' when selective sweeps involving new beneficial mutations result in perpetual oscillations of the coevolving traits on the slow evolutionary time scale. Mathematical models have shown that a prey and a predator can coevolve along a genetically driven Red Queen cycle. We found that embedding the prey-predator interaction into a three-species food chain that includes a coevolving superpredator often turns the genetically driven Red Queen cycle into chaos. A key condition is that the prey evolves fast enough. Red Queen chaos implies that the direction and strength of selection are intrinsically unpredictable beyond a short evolutionary time, with greatest evolutionary unpredictability in the superpredator. We hypothesize that genetically driven Red Queen chaos could explain why many natural populations are poised at the edge of ecological chaos. Over space, genetically driven chaos is expected to cause the evolutionary divergence of local populations, even under homogenizing environmental fluctuations, and thus to promote genetic diversity among ecological communities over long evolutionary time.

  11. Parasite transmission among relatives halts Red Queen dynamics.

    Science.gov (United States)

    Greenspoon, Philip B; Mideo, Nicole

    2017-03-01

    The theory that coevolving hosts and parasites create a fluctuating selective environment for one another (i.e., produce Red Queen dynamics) has deep roots in evolutionary biology; yet empirical evidence for Red Queen dynamics remains scarce. Fluctuating coevolutionary dynamics underpin the Red Queen hypothesis for the evolution of sex, as well as hypotheses explaining the persistence of genetic variation under sexual selection, local parasite adaptation, the evolution of mutation rate, and the evolution of nonrandom mating. Coevolutionary models that exhibit Red Queen dynamics typically assume that hosts and parasites encounter one another randomly. However, if related individuals aggregate into family groups or are clustered spatially, related hosts will be more likely to encounter parasites transmitted by genetically similar individuals. Using a model that incorporates familial parasite transmission, we show that a slight degree of familial parasite transmission is sufficient to halt coevolutionary fluctuations. Our results predict that evidence for Red Queen dynamics, and its evolutionary consequences, are most likely to be found in biological systems in which hosts and parasites mix mainly at random, and are less likely to be found in systems with familial aggregation. This presents a challenge to the Red Queen hypothesis and other hypotheses that depend on coevolutionary cycling. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  12. O QUEEN, A QUEEN: Controvérsias sobre gêneros e performances

    OpenAIRE

    Amaral, Adriana; Monteiro, Camila; Soares, Thiago

    2017-01-01

    A partir da apresentação ao vivo do grupo Queen, na edição 2015 do Rock in Rio, quando a banda inglesa de rock contou com um ex-integrante de reality show musical como vocalista, traça-se uma observação de controvérsias para pensar de que maneira as questões de gênero, com foco nas masculinidades, podem ser importantes ferramentas para pensar a construção do valor na música pop. A problemática trata das diferentes performances do masculino dos dois vocalistas (Freddie Mercury, o cantor origin...

  13. Transcriptomic response to injury sheds light on the physiological costs of reproduction in ant queens.

    Science.gov (United States)

    von Wyschetzki, Katharina; Lowack, Helena; Heinze, Jürgen

    2016-05-01

    The trade-off between reproduction and longevity is widespread among multicellular organisms. As an important exception, the reproductive females of perennial social insects (ants, honeybees, termites) are simultaneously highly fertile and very long-lived relative to their nonreproductive nestmates. The observation that increased fecundity is not coupled with decreased lifespan suggests that social insect queens do not have to reallocate resources between reproduction and self-maintenance. If queens have to compensate for the costs of reproduction on the level of the individual, the activation of other energy-demanding physiological processes might force them to reduce the production of eggs. To test this hypothesis in ant queens, we increased immunity costs by injury and measured the effect of this treatment on egg-laying rates and genomewide gene expression. Amputation of both middle legs led to a temporary decrease in egg-laying rates and affected the expression of 947 genes corresponding to 9% of the transcriptome. The changes comprised the upregulation of the immune and wound healing response on the one hand, and the downregulation of germ cell development, central nervous system development and learning ability on the other hand. Injury strongly influenced metabolism by inducing catabolism and repressing amino acid and nitrogen compound metabolism. By comparing our results to similar transcriptomic studies in insects, we found a highly consistent upregulation of immune genes due to sterile and septic wounding. The gene expression changes, complemented by the temporary decline of egg-laying rates, clearly reveal a trade-off between reproduction and the immune response in social insect queens. © 2016 John Wiley & Sons Ltd.

  14. The Red Queen theory of recombination hotspots.

    Science.gov (United States)

    Ubeda, F; Wilkins, J F

    2011-03-01

    Recombination hotspots are small chromosomal regions, where meiotic crossover events happen with high frequency. Recombination is initiated by a double-strand break (DSB) that requires the intervention of the molecular repair mechanism. The DSB repair mechanism may result in the exchange of homologous chromosomes (crossover) and the conversion of the allelic sequence that breaks into the one that does not break (biased gene conversion). Biased gene conversion results in a transmission advantage for the allele that does not break, thus preventing recombination and rendering recombination hotspots transient. How is it possible that recombination hotspots persist over evolutionary time (maintaining the average chromosomal crossover rate) when they are self-destructive? This fundamental question is known as the recombination hotspot paradox and has attracted much attention in recent years. Yet, that attention has not translated into a fully satisfactory answer. No existing model adequately explains all aspects of the recombination hotspot paradox. Here, we formulate an intragenomic conflict model resulting in Red Queen dynamics that fully accounts for all empirical observations regarding the molecular mechanisms of recombination hotspots, the nonrandom targeting of the recombination machinery to hotspots and the evolutionary dynamics of hotspot turnover. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  15. Enhancing the antitumor cell proliferation and Cu(2+)-chelating effects of black soybeans through fermentation with Aspergillus awamori.

    Science.gov (United States)

    Chen, Yu-Fei; Chiang, Ming-Lun; Chou, Cheng-Chun; Lo, Yi-Chen

    2013-04-01

    In the present study, black soybeans were fermented with Aspergillus awamori at 30°C for 3 days. The effect of fermentation on the antiproliferative effect against human colon cancer cells, Caco-2 and HT-29 as well as Cu(2+)-chelating effect of black soybeans was investigated. It was found that the water, 80% methanol or 80% ethanol extract of fermented black soybeans showed a significantly higher (P soybeans. Generally, the methanol extract and the ethanol extract of fermented black soybeans exerted higher antiproliferative effect on both Caco-2 and HT-29 cells. While water extract of fermented black soybeans showed the highest Cu(2+)-chelating effect among the various extracts examined. Taking into account of extraction yields further revealed that bioactive principles that exhibit Cu(2+)-chelating effect could be extracted to the largest extent with water as the extraction solvent. With same amount of sample, water extract obtained from fermented black soybeans possesses the highest Cu(2+)-chelating abilities. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Black Rice Anthocyanins Suppress Metastasis of Breast Cancer Cells by Targeting RAS/RAF/MAPK Pathway.

    Science.gov (United States)

    Chen, Xiang-Yan; Zhou, Jie; Luo, Li-Ping; Han, Bin; Li, Fei; Chen, Jing-Yao; Zhu, Yan-Feng; Chen, Wei; Yu, Xiao-Ping

    2015-01-01

    Overexpression of human epidermal growth factor receptor 2 (HER2) drives the biology of 30% of breast cancer cases. As a transducer of HER2 signaling, RAS/RAF/MAPK pathway plays a pivotal role in the development of breast cancer. In this study, we examined the molecular mechanisms underlying the chemopreventive effects of black rice anthocyanins (BRACs) extract and identified their molecular targets in HER2(+) breast cancer cells. Treatment of MDA-MB-453 cells (HER2(+)) with BRACs inhibited cell migration and invasion, suppressed the activation of mitogen-activated protein kinase kinase kinase (RAF), mitogen-activated protein kinase kinase (MEK), and c-Jun N-terminal kinase (JNK), and downregulated the secretion of matrix metalloproteinase 2 (MMP2) and MMP9. BRACs also weakened the interactions of HER2 with RAF, MEK, and JNK proteins, respectively, and decreased the mRNA expression of raf, mek, and jnk. Further, we found combined treatment with BRACs and RAF, MEK, or JNK inhibitors could enhance the antimetastatic activity, compared with that of each treatment. Transient transfection with small interfering RNAs (siRNAs) specific for raf, mek, and jnk inhibited their mRNA expression in MDA-MB-453 cells. Moreover, cotreatment with BRACs and siRNA induces a more remarkable inhibitory effect than that by either substance alone. In summary, our study suggested that BRACs suppress metastasis in breast cancer cells by targeting the RAS/RAF/MAPK pathway.

  17. Morphological aspects of cell reabsorption in laying queens and workers of Apis mellifera (Hymenoptera, Apidae Aspectos morfológicos da reabsorção celular em rainhas em postura e operárias de Apis mellifera (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    Karina Patrício

    2008-12-01

    Full Text Available The occurrence of cell reabsorption in the ovaries of queens in several rates of laying eggs, artificially impeded of laying, and in nurse workers, of Apis mellifera (Linnaeus, 1758, was studied with light (LM and transmission electron microscopy (TEM. Two types of structures were described and named by analogy with vertebrates ovarian structures, as corpus luteus, when resulting from the reabsorption of the follicular cells after ovulation, and corpus atresicus when resulting from total follicular reabsorption at any oocyte developmental stage. These structures have the same morphological characteristics and physiological signification in both castes. The corpus luteus occurrence indicates ovulation and its number is correspondent to the queen's rates of oviposition. The presence of this structure in nurse workers ovarioles shows that this caste may lay eggs. The incidence of corpus atresicus in queens decay with the increasing of the oviposition indicating that the inhibition of the normal sequence of oocyte maturation in the ovaries is deleterious. Both, corpus luteus and corpus atresicus incidence may be influenced by environmental factors.A ocorrência de reabsorção celular nos ovários de Apis mellifera (Linnaeus, 1758 foi estudada em operárias, em rainhas artificialmente impedidas de se acasalarem e em rainhas em postura utilizando microscopia de luz (LM e eletrônica de transmissão (MET. São descritos dois tipos de estruturas morfológicas, indicativas da ocorrência de reabsorção. Estas estruturas foram denominadas por analogia com estruturas correspondentes presentes nos ovários dos vertebrados. As resultantes de reabsorção das células foliculares depois da ovulação foram denominadas corpos lúteos e as resultantes da reabsorção de todo o folículo, em qualquer fase do desenvolvimento do ovócito, de corpos atrésicos. As estruturas representativas da reabsorção têm as mesmas características morfológicas e

  18. Black Phosphorus Quantum Dots for Hole Extraction of Typical Planar Hybrid Perovskite Solar Cells.

    Science.gov (United States)

    Chen, Wei; Li, Kaiwen; Wang, Yao; Feng, Xiyuan; Liao, Zhenwu; Su, Qicong; Lin, Xinnan; He, Zhubing

    2017-02-02

    Black phosphorus, famous as two-dimensional (2D) materials, shows such excellent properties for optoelectronic devices such as tunable direct band gap, extremely high hole mobility (300-1000 cm 2 /(V s)), and so forth. In this Letter, facile processed black phosphorus quantum dots (BPQDs) were successfully applied to enhance hole extraction at the anode side of the typical p-i-n planar hybrid perovskite solar cells, which remarkably improved the performance of devices with photon conversion efficiency ramping up from 14.10 to 16.69%. Moreover, more detailed investigations by c-AFM, SKPM, SEM, hole-only devices, and photon physics measurements discover further the hole extraction effect and work mechanism of the BPQDs, such as nucleation assistance for the growth of large grain size perovskite crystals, fast hole extraction, more efficient hole transfer, and suppression of energy-loss recombination at the anode interface. This work definitely paves the way for discovering more and more 2D materials with high electronic properties to be used in photovoltaics and optoelectronics.

  19. Survey of the Health Status of Some Honey Bee Queens in Italy

    Directory of Open Access Journals (Sweden)

    Porporato Marco

    2015-12-01

    Full Text Available While observing: non-acceptance, frequent replacements, and reduced performance in honey bee (Apis mellifera ligustica queens, we were induced to analyse a certain number of queens to detect the causes. For this purpose, 99 newly mated queens were bought from 20 Italian queen breeders. In addition, 109 older or at-the-end-of-their-career queens, that showed poor productivity, were collected from honey production hives throughout Italy. All the queens were dissected to check the status of their reproductive system and/or the presence of various anomalies and diseases.

  20. Effect of Different Substrates on the Acceptance of Grafted Larvae in Commercial Honey Bee (Apis Mellifera Queen Rearing

    Directory of Open Access Journals (Sweden)

    Contreras-Martinez Celia A.

    2017-12-01

    Full Text Available The need for the increased production of honey bee (Apis mellifera queens has led beekeepers to use different substrates in artificial queen cups where larvae destined to become queens are deposited (grafting. However, not enough scientific evidence exists that indicates that this practice is useful and what substance offers the best results. This study was conducted to determine with the Doolittle queen rearing method the acceptance rate of larvae deposited on different substrates during grafting and to determine if the sugar content and pH of the substrates used affect the acceptance of larvae in cell builder colonies. The evaluated substrates were coconut water, apple nectar, royal jelly, cola soda and distilled water, plus control (without substrate. Grafted larvae of the six treatments were introduced into cell builder colonies and their acceptance verified after 72 h. Apple nectar provided the highest rate of larvae acceptance with 81.06%, followed by cola soda with 62.93%, coconut water with 60.90%, royal jelly with 57.82% and distilled water with 58.99%. The larvae acceptance rates of all substrates were significantly higher than the control, which had an acceptance rate of 47.04%. No significant relationship was found between the sugar content of the substrates and larvae acceptance. However, although not significant, a high negative correlation was found between the substrate pH and the number of accepted larvae (Rho = - 0.90, p = 0.07. These results suggest that the use of liquid acidic substrates during larvae grafting, in particular apple nectar, may increase the production of honey bee queens.

  1. The Red Queen lives: Epistasis between linked resistance loci.

    Science.gov (United States)

    Metzger, César M J A; Luijckx, Pepijn; Bento, Gilberto; Mariadassou, Mahendra; Ebert, Dieter

    2016-02-01

    A popular theory explaining the maintenance of genetic recombination (sex) is the Red Queen Theory. This theory revolves around the idea that time-lagged negative frequency-dependent selection by parasites favors rare host genotypes generated through recombination. Although the Red Queen has been studied for decades, one of its key assumptions has remained unsupported. The signature host-parasite specificity underlying the Red Queen, where infection depends on a match between host and parasite genotypes, relies on epistasis between linked resistance loci for which no empirical evidence exists. We performed 13 genetic crosses and tested over 7000 Daphnia magna genotypes for resistance to two strains of the bacterial pathogen Pasteuria ramosa. Results reveal the presence of strong epistasis between three closely linked resistance loci. One locus masks the expression of the other two, while these two interact to produce a single resistance phenotype. Changing a single allele on one of these interacting loci can reverse resistance against the tested parasites. Such a genetic mechanism is consistent with host and parasite specificity assumed by the Red Queen Theory. These results thus provide evidence for a fundamental assumption of this theory and provide a genetic basis for understanding the Red Queen dynamics in the Daphnia-Pasteuria system. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  2. Do sexist organizational cultures create the Queen Bee?

    Science.gov (United States)

    Derks, Belle; Ellemers, Naomi; van Laar, Colette; de Groot, Kim

    2011-09-01

    'Queen Bees' are senior women in masculine organizational cultures who have fulfilled their career aspirations by dissociating themselves from their gender while simultaneously contributing to the gender stereotyping of other women. It is often assumed that this phenomenon contributes to gender discrimination in organizations, and is inherent to the personalities of successful career women. We argue for a social identity explanation and examine organizational conditions that foster the Queen Bee phenomenon. Participants were 94 women holding senior positions in diverse companies in The Netherlands who participated in an on-line survey. In line with predictions, indicators of the Queen Bee phenomenon (increased gender stereotyping and masculine self-descriptions) were found mostly among women who indicated they had started their career with low gender identification and who had subsequently experienced a high degree of gender discrimination on their way up. By contrast, the experience of gender discrimination was unrelated to signs of the Queen Bee phenomenon among women who indicated to be highly identified when they started their career. Results are discussed in light of social identity theory, interpreting the Queen Bee phenomenon as an individual mobility response of low gender identified women to the gender discrimination they encounter in their work. ©2010 The British Psychological Society.

  3. Mating with stressed males increases the fitness of ant queens.

    Directory of Open Access Journals (Sweden)

    Alexandra Schrempf

    Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.

  4. Bumblebee size polymorphism and worker response to queen pheromone

    Directory of Open Access Journals (Sweden)

    Luke Holman

    2014-09-01

    Full Text Available Queen pheromones are chemical signals produced by reproductive individuals in social insect colonies. In many species they are key to the maintenance of reproductive division of labor, with workers beginning to reproduce individually once the queen pheromone disappears. Recently, a queen pheromone that negatively affects worker fecundity was discovered in the bumblebee Bombus terrestris, presenting an exciting opportunity for comparisons with analogous queen pheromones in independently-evolved eusocial lineages such as honey bees, ants, wasps and termites. I set out to replicate this discovery and verify its reproducibility. Using blind, controlled experiments, I found that n-pentacosane (C25 does indeed negatively affect worker ovary development. Moreover, the pheromone affects both large and small workers, and applies to workers from large, mature colonies as well as young colonies. Given that C25 is readily available and that bumblebees are popular study organisms, I hope that this replication will encourage other researchers to tackle the many research questions enabled by the discovery of a queen pheromone.

  5. Social influence on age and reproduction: reduced lifespan and fecundity in multi-queen ant colonies.

    Science.gov (United States)

    Schrempf, A; Cremer, S; Heinze, J

    2011-07-01

    Evolutionary theories of ageing predict that life span increases with decreasing extrinsic mortality, and life span variation among queens in ant species seems to corroborate this prediction: queens, which are the only reproductive in a colony, live much longer than queens in multi-queen colonies. The latter often inhabit ephemeral nest sites and accordingly are assumed to experience a higher mortality risk. Yet, all prior studies compared queens from different single- and multi-queen species. Here, we demonstrate an effect of queen number on longevity and fecundity within a single, socially plastic species, where queens experience the similar level of extrinsic mortality. Queens from single- and two-queen colonies had significantly longer lifespan and higher fecundity than queens living in associations of eight queens. As queens also differ neither in morphology nor the mode of colony foundation, our study shows that the social environment itself strongly affects ageing rate. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  6. Mutation spectrum in FE1-MUTA(TM) Mouse lung epithelial cells exposed to nanoparticulate carbon black

    DEFF Research Database (Denmark)

    Jacobsen, Nicklas Raun; White, Paul A; Gingerich, John

    2011-01-01

    It has been shown previously that carbon black (CB), Printex 90 exposure induces cII and lacZ mutants in the FE1-Muta(TM) Mouse lung epithelial cell line and causes oxidatively damaged DNA and the production of reactive oxygen species (ROS). The purpose of this study was to determine the mutation...

  7. Non-transferable signals on ant queen eggs

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen

    2006-01-01

    become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such "cue scrambling" does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker......How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However......, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might...

  8. Red Queen dynamics with non-standard fitness interactions.

    Directory of Open Access Journals (Sweden)

    Jan Engelstädter

    2009-08-01

    Full Text Available Antagonistic coevolution between hosts and parasites can involve rapid fluctuations of genotype frequencies that are known as Red Queen dynamics. Under such dynamics, recombination in the hosts may be advantageous because genetic shuffling can quickly produce disproportionately fit offspring (the Red Queen hypothesis. Previous models investigating these dynamics have assumed rather simple models of genetic interactions between hosts and parasites. Here, we assess the robustness of earlier theoretical predictions about the Red Queen with respect to the underlying host-parasite interactions. To this end, we created large numbers of random interaction matrices, analysed the resulting dynamics through simulation, and ascertained whether recombination was favoured or disfavoured. We observed Red Queen dynamics in many of our simulations provided the interaction matrices exhibited sufficient 'antagonicity'. In agreement with previous studies, strong selection on either hosts or parasites favours selection for increased recombination. However, fast changes in the sign of linkage disequilibrium or epistasis were only infrequently observed and do not appear to be a necessary condition for the Red Queen hypothesis to work. Indeed, recombination was often favoured even though the linkage disequilibrium remained of constant sign throughout the simulations. We conclude that Red Queen-type dynamics involving persistent fluctuations in host and parasite genotype frequencies appear to not be an artefact of specific assumptions about host-parasite fitness interactions, but emerge readily with the general interactions studied here. Our results also indicate that although recombination is often favoured, some of the factors previously thought to be important in this process such as linkage disequilibrium fluctuations need to be reassessed when fitness interactions between hosts and parasites are complex.

  9. Red Queen dynamics with non-standard fitness interactions.

    Science.gov (United States)

    Engelstädter, Jan; Bonhoeffer, Sebastian

    2009-08-01

    Antagonistic coevolution between hosts and parasites can involve rapid fluctuations of genotype frequencies that are known as Red Queen dynamics. Under such dynamics, recombination in the hosts may be advantageous because genetic shuffling can quickly produce disproportionately fit offspring (the Red Queen hypothesis). Previous models investigating these dynamics have assumed rather simple models of genetic interactions between hosts and parasites. Here, we assess the robustness of earlier theoretical predictions about the Red Queen with respect to the underlying host-parasite interactions. To this end, we created large numbers of random interaction matrices, analysed the resulting dynamics through simulation, and ascertained whether recombination was favoured or disfavoured. We observed Red Queen dynamics in many of our simulations provided the interaction matrices exhibited sufficient 'antagonicity'. In agreement with previous studies, strong selection on either hosts or parasites favours selection for increased recombination. However, fast changes in the sign of linkage disequilibrium or epistasis were only infrequently observed and do not appear to be a necessary condition for the Red Queen hypothesis to work. Indeed, recombination was often favoured even though the linkage disequilibrium remained of constant sign throughout the simulations. We conclude that Red Queen-type dynamics involving persistent fluctuations in host and parasite genotype frequencies appear to not be an artefact of specific assumptions about host-parasite fitness interactions, but emerge readily with the general interactions studied here. Our results also indicate that although recombination is often favoured, some of the factors previously thought to be important in this process such as linkage disequilibrium fluctuations need to be reassessed when fitness interactions between hosts and parasites are complex.

  10. Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata.

    Directory of Open Access Journals (Sweden)

    Verena A Kottler

    Full Text Available The fitness of male guppies (Poecilia reticulata highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.

  11. TiN-conductive carbon black composite as counter electrode for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Li, G.R.; Wang, F.; Song, J.; Xiong, F.Y.; Gao, X.P.

    2012-01-01

    Highlights: ► The TiN nanoparticles are highly dispersed on conductive carbon black matrix (CCB). ► The well dispersion of TiN nanoparticles can improve electrochemical performance. ► The TiN/CCB shows a high photovoltaic performance with high conversion efficiency. - Abstract: TiN-conductive carbon black (CCB)/Ti electrodes are prepared by the nitridation of TiO 2 –CCB mixtures filmed on metallic Ti substrate in ammonia atmosphere. It is demonstrated from X-ray diffraction (XRD) and scanning electron microscopy (SEM) that TiN nanoparticles are highly dispersed on the CCB matrix in the composites. TiN–CCB/Ti electrodes show outstanding electrochemical performances as compared to individual TiN/Ti and CCB/Ti electrodes. In particular, the dye-sensitized solar cell (DSSC) using TiN–CCB (1:1, mass ratio)/Ti electrode presents an energy conversion efficiency of 7.92%, which is higher than that (6.59%) of the device using Pt/FTO (fluorine doped tin oxide) electrode measured under the same test conditions. Based on the analysis of cyclic voltammetry (CV) and electrochemical impedance spectra (EIS), the enhancements for the electrochemical and photochemical performance of TiN–CCB/Ti electrodes are attributed to the fact that the dispersed TiN nanoparticles in the CCB matrix provide an improved electrocatalytic activity and a facilitated diffusion for triiodine ions. This work shows a facile approach to develop metal nitrides–carbon composites as counter electrodes for DSSCs. High energy conversion efficiency and low lost will make the composites have significant potential for replacing the conventional Pt/FTO electrodes in DSSCs.

  12. Discovery of Black Dye Crystal Structure Polymorphs: Implications for Dye Conformational Variation in Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Cole, Jacqueline M; Low, Kian Sing; Gong, Yun

    2015-12-23

    We present the discovery of a new crystal structure polymorph (1) and pseudopolymorph (2) of the Black Dye, one of the world's leading dyes for dye-sensitized solar cells, DSSCs (10.4% device performance efficiency). This reveals that Black Dye molecules can adopt multiple low-energy conformers. This is significant since it challenges existing models of the Black Dye···TiO2 adsorption process that renders a DSSC working electrode; these have assumed a single molecular conformation that refers to the previously reported Black Dye crystal structure (3). The marked structural differences observed between 1, 2, and 3 make the need for modeling multiple conformations more acute. Additionally, the ordered form of the Black Dye (1) provides a more appropriate depiction of its anionic structure, especially regarding its anchoring group and NCS bonding descriptions. The tendency toward NCS ligand isomerism, evidenced via the disordered form 2, has consequences for electron injection and electron recombination in Black Dye embedded DSSC devices. Dyes 2 and 3 differ primarily by the absence or presence of a solvent of crystallization, respectively; solvent environment effects on the dye are thereby elucidated. This discovery of multiple Black Dye conformers from diffraction, with atomic-level definition, complements recently reported nanoscopic evidence for multiple dye conformations existing at a dye···TiO2 interface, for a chemically similar DSSC dye; those results emanated from imaging and spectroscopy, but were unresolved at the submolecular level. Taken together, these findings lead to the general notion that multiple dye conformations should be explicitly considered when modeling dye···TiO2 interfaces in DSSCs, at least for ruthenium-based dye complexes.

  13. Novel single-layer gas diffusion layer based on PTFE/carbon black composite for proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Chen-Yang, Y.W.; Hung, T.F.; Yang, F.L. [Department of Chemistry and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li 32023 (China); Huang, J. [Yeu Ming Tai Chemical Industrial Co., Ltd, Taichung 40768 (China)

    2007-11-08

    A series of poly(tetrafluoroethylene)/carbon black composite-based single-layer gas diffusion layers (PTFE/CB-GDLs) for proton exchange membrane fuel cell (PEMFC) was successfully prepared from carbon black and un-sintered PTFE, which included powder resin and colloidal dispersion, by a simple inexpensive method. The scanning electron micrographs of PTFE/CB-GDLs indicated that the PTFE resins were homogeneously dispersed in the carbon black matrix and showed a microporous layer (MPL)-like structure. The as-prepared PTFE/CB-GDLs exhibited good mechanical property, high gas permeability, and sufficient water repellency. The best current density obtained from the PEMFC with the single-layer PTFE/CB-GDL was 1.27 and 0.42 A cm{sup -2} for H{sub 2}/O{sub 2} and H{sub 2}/air system, respectively. (author)

  14. Endothelial cell hyperproliferation and stratification in uteroplacental blood vessels of the black mastiff bat, Molossus rufus.

    Science.gov (United States)

    Rasweiler, J J; Badwaik, N K; Salame, G; Abulafia, O

    2011-09-01

    Placentation was studied histologically and immunocytochemically in black mastiff bats obtained at frequent intervals throughout pregnancy. These were bred in a captive colony or collected from a reproductively-synchronized wild population. During late pregnancy, the single fetus was largely sustained by a discoidal, hemochorial placenta located at the cranial end of the right uterine horn. This invariant positioning was determined by a vascular tuft that developed there both during early pregnancy and non-pregnant cycles. This provided a scaffold for early placental morphogenesis. As development proceeded, small arterioles and venules serving the tuft were converted to large uteroplacental vessels. Within the base of the placenta, these became lined by an unusual vascular epithelium composed of intermingled patches of multilayered endothelial cells and cytotrophoblast. Initially, the endothelium became multilayered by hypertrophy, proliferation, and infolding of its basal lamina. These created endothelial bilayers usually insinuated between basal laminae. The development of temporary gaps in the laminae then permitted further enlargement of the vessels and proliferation of the endothelial cells as monolayer sheets or chains. The latter were interconnected, forming a complex, stratified, cellular network associated with a prominent meshwork of basal laminae. Throughout much of pregnancy, these endothelial cells were cuboidal to columnar and possessed an abundance of basal glycoprotein granules presumably containing basal lamina precursors. The cells also expressed vimentin and frequently von Willebrand factor, but not cytokeratins or desmin. Pronounced thickening of the endothelia and amplification of their basal laminae likely evolved to greatly strengthen the walls of the uteroplacental vessels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Selection against aerial dispersal in ants: two non-flying queen phenotypes in Pogonomyrmex laticeps.

    Directory of Open Access Journals (Sweden)

    Christian Peeters

    Full Text Available The South American seed-harvester ant Pogonomyrmex laticeps has dimorphic queens: ergatoid (permanently wingless and brachypterous (short, non-functional wings. Surveys in western Argentina indicated that colonies near Chilecito, La Rioja Province, produced only ergatoid queens, while those near Punta Balasto, Catamarca Province (263 km away, produced only brachypterous queens. Brachypterous queens were significantly larger than ergatoid queens for 10 of 11 external characters, but both phenotypes had comparable reproductive potential, i.e., a spermatheca and a similar number of ovarioles. Using normal winged queens of the closely related P. uruguayensis for comparison, we determined that both queen phenotypes in P. laticeps had a full set of dorsal thoracic sclerites, albeit each sclerite was much reduced, whereas workers had a thorax without distinct dorsal sclerites. Sclerites were fused and immobile in ergatoid queens, while they were separable and fully articulated in brachypterous queens. Both phenotypes lacked the big indirect flight muscles, but brachypterous queens retained the tiny direct flight muscles. Overall, this dimorphism across populations indicates that there are alternative solutions to selective pressures against flying queens. We lack field data about colony founding strategy (independent or dependent for either queen phenotype, but colonies at both sites produced numerous gynes, and we infer that all foundresses initiate colonies independently and are obligate foragers.

  16. The importance of workers for queen hibernation survival in Camponotus ants.

    Science.gov (United States)

    Shiroto, Akiyoshi; Satoh, Toshiyuki; Hirota, Tadao

    2011-05-01

    The higher proportion of polygynous ant species in northern areas indicates that cold climates influence queen number per colony. It is unclear, however, what ecological and physiological factors facilitate the dominance of polygynous species in cold climates. This is the case in two common arboreal ants in Japan-Camponotus yamaokai and C. nawai-which are quite similar in morphology, but different in social structure and geographical distribution. Polygynous C. yamaokai inhabits colder areas, whereas monogynyous C. nawai inhabits warmer climates. We compared queen survival in both ants at low temperature to evaluate whether interspecific difference in cold tolerance can explain the geographical distribution. We examined the influence of cohabitation with other individuals, as well as individual cold tolerance. Experimental groups with different caste compositions were prepared and maintained under conditions simulating in the laboratory climates of the northern limit of C. nawai. Wintering experiments revealed that C. yamaokai queens survived longer than C. nawai queens under solitary conditions, although half of the queens died in less than a month, even in C. yamaokai. Queens hibernating with workers survived longer than solitary queens, but queen number did not affect queen survival. Cohabitation with workers allowed 80% of C. yamaokai queens to survive more than two months. Under field conditions, monogynous C. nawai foundresses overwinter without workers, whereas new queens of polygynous C. yamaokai always overwinter with many workers. Thus, the geographical distribution of these ants appears to depend on the overwintering behavior of new queens.

  17. Gender-bias primes elicit queen-bee responses among senior Policewomen

    NARCIS (Netherlands)

    Derks, B.; Laar, C. van; Ellemers, N.; Groot, K. de

    2011-01-01

    Queen bees are senior women in male-dominated organizations who have achieved success by emphasizing how they differ from other women. Although the behavior of queen bees tends to be seen as contributing to gender disparities in career outcomes, we argue that queen-bee behavior is actually a result

  18. Deformed wing virus can be transmitted during natural mating in honey bees and infect the queens

    DEFF Research Database (Denmark)

    Amiri, Esmaeil; Meixner, Marina D.; Kryger, Per

    2016-01-01

    oviposition, viral quantification revealed that seven of the 30 queens had high-level deformed wing virus infections, in all tissues, including the semen stored in the spermathecae. Two groups of either unmated queens (n = 8) with induced egg laying, or queens (n = 12) mated in isolation with drones showing...

  19. Selfish strategies and honest signalling: reproductive conflicts in ant queen associations

    DEFF Research Database (Denmark)

    Holman, Luke; Dreier, Stephanie; d'Ettorre, Patrizia

    2010-01-01

    . Here, we use a brood transfer experiment to test whether cofounding queens of the ant Lasius niger 'selfishly' adjust their productivity when sharing the nest with future competitors. We simultaneously analysed queen cuticular hydrocarbon (CHC) profiles to investigate whether queens honestly signal...

  20. A genetic component to size in queens of the ant, Formica truncorum

    DEFF Research Database (Denmark)

    Bargum, Katja; Boomsma, Jacobus Jan; Sundström, L.

    2004-01-01

    . In this study, we present the first evidence of an additive genetic component to queen size in ants, using maternal half sib analysis. We also compared intra-colony size variation in colonies with high (queen doubly mated) versus low (queen singly mated) genetic variability. We found a high and significant...

  1. Sex determination from femoral head diameters in black Malawians ...

    African Journals Online (AJOL)

    Objectives: To determine the sex of black Malawians from femoral head diameters. Design: A retrospective study on patients investigated in three x-ray departments. Setting: Radiographs were collected from the archives of Queen Elizabeth Central, Chikwawa and Balaka hospitals. Subject: X-ray films of 496 pelves of adult ...

  2. Inhibitory effects of black pepper (Piper nigrum) extracts and compounds on human tumor cell proliferation, cyclooxygenase enzymes, lipid peroxidation and nuclear transcription factor-kappa-B.

    Science.gov (United States)

    Liu, Yunbao; Yadev, Vivek R; Aggarwal, Bharat B; Nair, Muraleedharan G

    2010-08-01

    Black pepper (Piper nigrum) and hot pepper (Capsicum spp.) are widely used in traditional medicines. Although hot Capsicum spp. extracts and its active principles, capsaicinoids, have been linked with anticancer and anti-inflammatory activities, whether black pepper and its active principle exhibit similar activities is not known. In this study, we have evaluated the antioxidant, anti-inflammatory and anticancer activities of extracts and compounds from black pepper by using proinflammatory transcription factor NF-kappaB, COX-1 and -2 enzymes, human tumor cell proliferation and lipid peroxidation (LPO). The capsaicinoids, the alkylamides, isolated from the hot pepper Scotch Bonnet were also used to compare the bioactivities of alkylamides and piperine from black pepper. All compounds derived from black pepper suppressed TNF-induced NF-kappaB activation, but alkyl amides, compound 4 from black pepper and 5 from hot pepper, were most effective. The human cancer cell proliferation inhibitory activities of piperine and alklyl amides in Capsicum and black pepper were dose dependant. The inhibitory concentrations 50% (IC50) of the alklylamides were in the range 13-200 microg/mL. The extracts of black pepper at 200 microg/mL and its compounds at 25 microg/mL inhibited LPO by 45-85%, COX enzymes by 31-80% and cancer cells proliferation by 3.5-86.8%. Overall, these results suggest that black pepper and its constituents like hot pepper, exhibit anti-inflammatory, antioxidant and anticancer activities.

  3. Acute bacterial meningitis in children admitted to the Queen ...

    African Journals Online (AJOL)

    In order to design appropriate interventioos, we collected clinical and demographic data prospectively on all children aged one day to 14 years admitted with a diagnosis of bacterial meningitis (BM) from April 1st 1996 to March 31st 1997 to the Queen Elizabeth Central Hospital (QECH), Blantyre Malawi. During the study ...

  4. Adult Education and Social Sustainability: Harnessing the "Red Queen Effect"

    Science.gov (United States)

    Easton, Peter

    2007-01-01

    In 1973, the evolutionary biologist Leigh Van Valen of the University of Chicago devised what he called the "Red Queen Effect" to describe the growth and development of species. It stipulated that an evolutionary system must continue to develop just to maintain its fitness relative to others evolving in its environment. The literary reference is…

  5. Taxi 'sugar daddies' and taxi queens: Male taxi driver attitudes ...

    African Journals Online (AJOL)

    Cheryl Potgieter, Anna Strebel, Tamara Shefer, and Claire Wagner

    2012-12-14

    Dec 14, 2012 ... have sex with the drivers in exchange for gifts and money. The extent to which such relationships might facilitate unsafe sexual practices and increased risks for both the men and the young women, often referred to as taxi queens, remains an important question in the light of the current challenges of ...

  6. Expanding the Canadian Queen Elizabeth II Diamond Jubilee ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project will expand the reach and deepen the impact of the original Canadian Queen Elizabeth II Diamond Jubilee Scholarships program (QES) through a new component supporting ... IDRC is now accepting applications for this year's Trees and People: Resilience in a changing climate John G. Bene Fellowship 2018.

  7. Standard methods for rearing and selection of Apis mellifera queens

    DEFF Research Database (Denmark)

    Büchler, Ralph; Andonov, Sreten; Bienefeld, Kaspar

    2013-01-01

    Here we cover a wide range of methods currently in use and recommended in modern queen rearing, selection and breeding. The recommendations are meant to equally serve as standards for both scientific and practical beekeeping purposes. The basic conditions and different management techniques for q...

  8. Biochemical derangements prior to emergency laparotomy at Queen ...

    African Journals Online (AJOL)

    Background: The aim of this study was to examine biochemical investigations not routinely performed prior to emergency laparotomy in patients at Queen Elizabeth Central Hospital, a low-resource public hospital in Blantyre, Malawi.. Methods: A prospective cross-sectional study of adults (N = 15) needing emergency ...

  9. An audit of deliveries and outcome at Queen Elizabeth Central ...

    African Journals Online (AJOL)

    A one-year audit of deliveries at Queen Elizabeth Central Hospital, Blantyre, was undertaken for 1999. The main objective of the audit was to obtain baseline data on forms of deliveries and pregnancy outcome. A total of 12,293 births occurred during the study period. Of these, 11,565 were singleton deliveries, 349 twin ...

  10. Determinants of Post-Partum Maternal Mortality at Queen Elizabeth ...

    African Journals Online (AJOL)

    The aim of this research is to identify the clinical, demographic and service-based determinants of postpartum maternal mortality within Queen Elizabeth Central Hospital, Blantyre, Malawi, during 2001 and 2002. The study uses a case-control design using all postpartum maternal deaths in 2001 and 2002 as cases, with ...

  11. Birth weights and gestational ages of Malawian newborns at Queen ...

    African Journals Online (AJOL)

    Objective: To determine the distributions of birth weight (BW) and gestational age (GA) and calculate rates of still birth (SB) of four years delivery in the Queen Elizabeth Central Hospital( QECH). Methods: Retrospective analysis was carried out on data of deliveries conducted between January 2000 and December 2003.

  12. The Red Queen: Sex and the Evolution of Human Nature

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 1. The Red Queen: Sex and the Evolution of Human Nature. Milind G Watve. Book Review Volume 3 Issue 1 January 1998 pp 79- ... Author Affiliations. Milind G Watve1. ME Society, Abasaheb Garware College, Karve Road, Pune 411 004, India.

  13. Non-transferable signals on ant queen eggs

    Science.gov (United States)

    D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen; Ratnieks, Francis L. W.

    2006-03-01

    How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such “cue scrambling” does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker-laid eggs. Chemical analyses also showed that the surface hydrocarbon profile of these eggs was unchanged. Policing, therefore, is stable against this potential cheating mechanism probably because queen-laid eggs are made chemically distinct using chemicals, that are not easily transferred by physical contact.

  14. Setting up kangaroo mother care at Queen Elizabeth Central ...

    African Journals Online (AJOL)

    Setting up kangaroo mother care at Queen Elizabeth Central Hospital, Blantyre - a practical approach. H Blencowe, EM Molyneux. Abstract. No Abstract. Malawi Medical Journal Vol. 17(2) 2005: 39-42. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  15. Queens Tri-School Confederation, 1991-92 Evaluation Report.

    Science.gov (United States)

    Hannah, Susan; Dworkowitz, Barbara

    An evaluation was done of the Queens Tri-School Confederation, three high schools in the New York City Public Schools funded by a federal grant from the Magnet Schools Assistance Program. The grant provided Hillcrest, Jamaica, and Thomas A. Edison High Schools with funds to develop or expand emergency technician programs at Hillcrest; a law…

  16. Queen leads tributes to nurses in wake of terrorist attacks.

    Science.gov (United States)

    Allen, Daniel

    2017-06-15

    The Queen and the prime minister led tributes to nurses and other NHS staff caring for people injured in the recent terrorist attacks in Manchester and London. Emergency services worked through the night to assist in the immediate aftermath of the explosion at the Manchester arena, which killed 22 people and left many more injured, who were treated at hospitals across the city.

  17. The Queen's Two Bodies: Sor Juana and New Spain's Vicereines

    Science.gov (United States)

    Thomas, George Anthony

    2009-01-01

    The work of Sor Juana Ines de la Cruz contains many examples of positive representations of the Queens of Spain and the Vicereines of New Spain. These poetic portraits serve to counter the primarily misogynistic portrayals of ruling women of the seventeenth century. Most importantly, Sor Juana increased the visibility of the vicereine in colonial…

  18. Ross Ice Shelf and the Queen Maude Mounains, Antarctica

    Science.gov (United States)

    1991-01-01

    Part of the Ross Ice Shelf and the Queen Maude Mounains of Antarctica (55.5N, 178.0W) are in the background of this scene, oriented toward the south. Low stratocumulus clouds are predominant throughout most of the scene.

  19. Differences in beta-cell function and insulin secretion in Black vs. White obese adolescents: Do incretin hormones play a role?

    Science.gov (United States)

    Black youth are at higher risk for type 2 diabetes (T2D) than their White peers. Previously we demonstrated that for the same degree of insulin sensitivity, Black youth have an upregulated beta-cell function and insulin hypersecretion, in response to intravenous (IV) glucose, compared with Whites. T...

  20. Number of queens in founding associations of the ponerine ant Pachycondyla villosa

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Kellner, K.; Delabie, J. H. C.

    2005-01-01

    In the ant Pachycondyla villosa, new colonies are usually started cooperatively by two or more young queens who establish a dominance order with a division of labour. Co-founding can lead to primary polygyny, where queens stay together after workers have emerged. Here we show that two queens...... associations are the most common (47%) and also the most stable in the field. When offered additional nest sites in the laboratory, two-queen associations did not split, whereas larger associations did so. We also show that solitary foundresses always accepted experimentally introduced alien queens, while...

  1. Primary sex ratio adjustment by ant queens in response to local mate competition

    DEFF Research Database (Denmark)

    de Menten, Ludivine; Cremer, Sylvia; Heinze, Jürgen

    2005-01-01

    In the ant Cardiocondyla obscurior, wingless males compete with nestmate males for access to female mating partners, leading to local mate competition (LMC). Queen number varies between colonies, resulting in variation in the strength of LMC. Cremer & Heinze (2002, Proceedings of the Royal Society...... to adult sex ratios. With LMC, the primary sex ratio (proportion of haploid eggs laid by the queen) is expected to be female biased, which lowers the conflict between queens and workers over sex allocation. We compared the primary sex ratios laid by queens in monogynous and in polygynous experimental...... sex ratio in response to LMC by ant queens....

  2. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as is hi...... suggested that appreciation of the highly personal motives of both Siouxsie Sioux and Janelle Monáe in wearing black may be achieved via analogies with the minimalist sublime of American artists Frank Stella’s and Ad Reinhardt’s black canvasses.......Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as...... is hinted by Rudyard Kipling’s illustration of ‘The [Black] Cat That Walked by Himself’ in his classic children’s tale). It was well understood by uniformed Anarchists, Fascists and the SS that there is an assertive presence connected with the black-clad figure. The paradox of black’s abstract elegance...

  3. 75 FR 68397 - DeQueen and Eastern Railroad, LLC-Acquisition and Operation Exemption-DeQueen and Eastern...

    Science.gov (United States)

    2010-11-05

    ..., DeQueen and Eastern Railroad, LLC, Golden Triangle Railroad, LLC, Mississippi & Skuna Valley Railroad, LLC... & Cowlitz Railway Company; (2) Docket No. FD 35428, Golden Triangle Railroad, LLC--Acquisition and Operation Exemption--Golden Triangle Railroad Company; (3) Docket No. FD 35429, Mississippi & Skuna Valley Railroad...

  4. Interstitial cell tumor in a black-and-white ruffed lemur (Varecia variegatus variegatus).

    Science.gov (United States)

    Neiffer, D L; Klein, E C

    2001-06-01

    A 14.5-yr-old, male black-and-white ruffed lemur (Varecia variegatus variegatus) presented for acute enlargement of the left testicle and hemiscrotum. Physical examination also revealed poor pelage quality with short guard hairs, sparse undercoat, and areas of alopecia. Increased aggression was also reported. A unilateral, open orchiectomy was performed, with the left testicle, epidydymis, associated vaginal tunic, and attached spermatic cord removed. Microscopic evaluation was consistent with an interstitial cell tumor, with many morphologic features similar to this neoplasm in people. No overt histopathologic criteria of malignancy were present. Following orchiectomy, gradual improvement in pelage quality was noted and was considered almost normal by 5 mo postoperative. In contrast with the aggressive preoperative behavior, the lemur was extremely submissive for 3 mo following the surgery. Gradual return to normal behavior and social status occurred over the next 2 mo. Multiple follow-up examinations and radiographs revealed no evidence of metastasis, and biopsy of the remaining testicle 4 mo later revealed no evidence of neoplasia. Serial measurements of testosterone and estradiol revealed levels within the range of those for other ruffed lemurs, as were repeated measurements taken of the remaining testicle. At 19 mo postoperative, the lemur had a coat quality considered nearly normal and maintained its historical social position in the lemur group without abnormal aggressive behavior.

  5. Enhanced Activated Carbon Cathode Performance for Microbial Fuel Cell by Blending Carbon Black

    KAUST Repository

    Zhang, Xiaoyuan

    2014-02-04

    Activated carbon (AC) is a useful and environmentally sustainable catalyst for oxygen reduction in air-cathode microbial fuel cells (MFCs), but there is great interest in improving its performance and longevity. To enhance the performance of AC cathodes, carbon black (CB) was added into AC at CB:AC ratios of 0, 2, 5, 10, and 15 wt % to increase electrical conductivity and facilitate electron transfer. AC cathodes were then evaluated in both MFCs and electrochemical cells and compared to reactors with cathodes made with Pt. Maximum power densities of MFCs were increased by 9-16% with CB compared to the plain AC in the first week. The optimal CB:AC ratio was 10% based on both MFC polarization tests and three electrode electrochemical tests. The maximum power density of the 10% CB cathode was initially 1560 ± 40 mW/m2 and decreased by only 7% after 5 months of operation compared to a 61% decrease for the control (Pt catalyst, 570 ± 30 mW/m2 after 5 months). The catalytic activities of Pt and AC (plain or with 10% CB) were further examined in rotating disk electrode (RDE) tests that minimized mass transfer limitations. The RDE tests showed that the limiting current of the AC with 10% CB was improved by up to 21% primarily due to a decrease in charge transfer resistance (25%). These results show that blending CB in AC is a simple and effective strategy to enhance AC cathode performance in MFCs and that further improvement in performance could be obtained by reducing mass transfer limitations. © 2014 American Chemical Society.

  6. Formation of Platinum Catalyst on Carbon Black Using an In‐Liquid Plasma Method for Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Show

    2017-01-01

    Full Text Available Platinum (Pt catalyst was formed on the surface of carbon black using an in‐liquid plasma method. The formed Pt catalyst showed the average particle size of 4.1 nm. This Pt catalyst was applied to a polymer electrolyte membrane fuel cell (PEMFC. The PEMFC showed an open voltage of 0.85 V and a maximum output power density of 216 mW/cm2.

  7. Heart failure with preserved ejection fraction in women: the Dutch Queen of Hearts program.

    Science.gov (United States)

    den Ruijter, H; Pasterkamp, G; Rutten, F H; Lam, C S P; Chi, C; Tan, K H; van Zonneveld, A J; Spaanderman, M; de Kleijn, D P V

    2015-02-01

    Heart failure (HF) poses a heavy burden on patients, their families and society. The syndrome of HF comes in two types: with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). The latter is on the increase and predominantly present in women, especially the older ones. There is an urgent need for mortality-reducing drugs in HFpEF, a disease affecting around 5 % of those aged 65 years and over. HFpEF develops in patients with risk factors and comorbidities such as obesity, hypertension, diabetes, COPD, but also preeclampsia. These conditions are likely to drive microvascular disease with involvement of the coronary microvasculature, which may eventually evolve into HFpEF. Currently, the diagnosis of HFPEF relies mainly on echocardiography. There are no biomarkers that can help diagnose female microvascular disease or facilitate the diagnosis of (early stages of) HFpEF. Recently a Dutch consortium was initiated, Queen of Hearts, with support from the Netherlands Heart Foundation, with the aim to discover and validate biomarkers for diastolic dysfunction and HFpEF in women. These biomarkers come from innovative blood-derived sources such as extracellular vesicles and circulating cells. Within the Queen of Hearts consortium, we will pursue female biomarkers that have the potential for further evolution in assays with point of care capabilities. As a spin-off, the consortium will gain knowledge on gender-specific pathology of HFpEF, possibly opening up novel treatment options.

  8. No evidence of volatile chemicals regulating reproduction in a multiple queen ant

    Science.gov (United States)

    Coston, Duncan J.; Gill, Richard J.; Hammond, Robert L.

    2011-07-01

    Efficient cooperation in eusocial insect colonies requires effective communication, and there is abundant evidence of non-volatile chemicals playing a role in regulating reproduction within colonies. In contrast, there have been fewer studies investigating the role of volatile chemicals. This study investigated the potential role of volatile chemicals in regulating queen reproduction either by directly inhibiting queen reproduction or by honestly signalling queen fecundity to workers. We tested this using multiple queen colonies of the ant ( Leptothorax acervorum) from a functionally monogynous population where one queen monopolizes all reproduction. Nine colonies, each with an established laying queen, were split to produce two colony fragments—one containing the reproducing queen (group 1) and one containing only previously non-reproducing queens (group 2). Each group was separated by a fine wire mesh preventing physical contact, but allowing volatile chemical contact. In each group 2 fragment, we found that a single formerly non-reproductive queen commenced reproduction and that the rate of egg laying and maximum number of eggs recorded did not significantly differ between groups 1 and 2, results that do not support volatile chemicals as playing a role in regulating queen reproduction. Instead, our findings suggest that physical contact is necessary to maintain functional monogyny.

  9. Risk of red queen dynamics in pneumococcal vaccine strategy.

    Science.gov (United States)

    Jefferies, Johanna M C; Clarke, Stuart C; Webb, Jeremy S; Kraaijeveld, Alex R

    2011-08-01

    Pathogens increasingly evade current vaccines, and new strategies to control them are needed. There is mounting evidence that replacement of vaccine serotypes of Streptococcus pneumoniae with non-vaccine serotypes has taken place following widespread use of limited-serotype conjugate vaccines. New strategies to control vaccine evasion are needed and understanding evolutionary theory is important for the development of such approaches. Hosts are under selection pressure to evolve resistance against pathogens whereas pathogens are under selection pressure to evolve counter-resistance against the resistance mechanism of their host. Evolutionary changes in both host and pathogen lead to a continuous turnover of host and pathogen genotypes; this is known as Red Queen dynamics. We argue that integrating evolutionary thinking into pneumococcal vaccine design will lead to the avoidance of Red Queen dynamics and improved interventions against pneumococci. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. The Evolutionary Ecology of Multi-Queen Breeding in Ants

    DEFF Research Database (Denmark)

    Huszár, Dóra Borbála

    Ants, like other social insects, have evolved cooperative societies based on kinship. Colonies headed by a single breeding queen (monogyny) was the ancestral state but today ca. half of the ant species live in multi-queen societies (polygyny), which can sometimes reach extreme sizes (supercolony...... that only ants, not the other obligatorily social insects were able to decrease social and sexual conflicts sufficiently to make polygyny reach obligate form in some species. This can be explained by general ant biology, such as perennial lifehistories, foraging on foot instead of wings and having one...... mating event in life instead of ongoing events between pairs. Second, by empirical studies on the native ant species Myrmica rubra we were able to demonstrate that the three social syndromes can co-exist within populations, but with possible overlap in certain traits. Genetic and morphology results...

  11. Genetic relatedness does not predict the queen's successors in the ...

    Indian Academy of Sciences (India)

    Saikat Chakraborty

    raa, rbb, rccetc., are all 1. Model 1: According to this model the successor is that individual who has the highest relatedness to the queen. The model is illustrated below. a b c (Q) d a raa rab rac rad b rba rbb rbc rbd c (Q) rca rcb rcc rcd d rda rdb rdc rdd a, b, c, d are nest mates. rij is the pair-wise genetic relatedness between ...

  12. Chaotic provinces in the kingdom of the Red Queen.

    Science.gov (United States)

    Schenk, Hanna; Traulsen, Arne; Gokhale, Chaitanya S

    2017-10-27

    The interplay between parasites and their hosts is found in all kinds of species and plays an important role in understanding the principles of evolution and coevolution. Usually, the different genotypes of hosts and parasites oscillate in their abundances. The well-established theory of oscillatory Red Queen dynamics proposes an ongoing change in frequencies of the different types within each species. So far, it is unclear under what conditions Red Queen dynamics persists, especially when the number of types per species increases. Some models show that with many types of hosts and parasites or more species chaotic dynamics occur. In our analysis, an arbitrary number of types within two species are examined in a deterministic framework with constant or changing population size and very simple interactions. This general framework allows for analytical solutions for internal fixed points and their stability. The numerical analysis shows that for two species, once more than two types are considered per species, irregular dynamics in their frequencies can be observed in the long run. The nature of the dynamics depends strongly on the initial configuration of the system; the usual regular Red Queen oscillations are only observed when all types initially have similar abundance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Anti-oxidative and inflammatory responses induced by fly ash particles and carbon black in lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Diabate, Silvia; Plaumann, Diana; Uebel, Caroline; Weiss, Carsten [Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Eggenstein-Leopoldshafen (Germany); Bergfeldt, Britta [Karlsruhe Institute of Technology, Institute of Technical Chemistry, Eggenstein-Leopoldshafen (Germany)

    2011-12-15

    Combustion-derived nanoparticles as constituents of ambient particulate matter have been shown to induce adverse health effects due to inhalation. However, the components inducing these effects as well as the biological mechanisms are still not fully understood. The fine fraction of fly ash particles collected from the electrostatic precipitator of a municipal solid waste incinerator was taken as an example for real particles with complex composition released into the atmosphere to study the mechanism of early biological responses of BEAS-2B human lung epithelial cells. The studies include the effects of the water-soluble and -insoluble fractions of the fly ash and the well-studied carbon black nanoparticles were used as a reference. Fly ash induced reactive oxygen species (ROS) and increased the total cellular glutathione (tGSH) content. Carbon black also induced ROS generation; however, in contrast to the fly ash, it decreased the intracellular tGSH. The fly ash-induced oxidative stress was correlated with induction of the anti-oxidant enzyme heme oxygenase-1 and increase of the redox-sensitive transcription factor Nrf2. Carbon black was not able to induce HO-1. ROS generation, tGSH increase and HO-1 induction were only induced by the insoluble fraction of the fly ash, not by the water-soluble fraction. ROS generation and HO-1 induction were markedly inhibited by pre-incubation of the cells with the anti-oxidant N-acetyl cysteine which confirmed the involvement of oxidative stress. Both effects were also reduced by the metal chelator deferoxamine indicating a contribution of bioavailable transition metals. In summary, both fly ash and carbon black induce ROS but only fly ash induced an increase of intracellular tGSH and HO-1 production. Bioavailable transition metals in the solid water-insoluble matrix of the fly ash mostly contribute to the effects. (orig.)

  14. Depression of brain dopamine and its metabolite after mating in European honeybee (Apis mellifera) queens

    Science.gov (United States)

    Harano, Ken-Ichi; Sasaki, Ken; Nagao, Takashi

    2005-07-01

    To explore neuro-endocrinal changes in the brain of European honeybee (Apis mellifera) queens before and after mating, we measured the amount of several biogenic amines, including dopamine and its metabolite in the brain of 6- and 12-day-old virgins and 12-day-old mated queens. Twelve-day-old mated queens showed significantly lower amounts of dopamine and its metabolite (N-acetyldopamine) than both 6- and 12-day-old virgin queens, whereas significant differences in the amounts of these amines were not detected between 6- and 12-day-old virgin queens. These results are explained by down-regulation of both synthesis and secretion of brain dopamine after mating. It is speculated that higher amounts of brain dopamine in virgin queens might be involved in activation of ovarian follicles arrested in previtellogenic stages, as well as regulation of their characteristic behaviors.

  15. Reclaiming the crown: queen to worker conflict over reproduction in Aphaenogaster cockerelli

    Science.gov (United States)

    Smith, Adrian A.; Hölldobler, Bert; Liebig, Jürgen

    2011-03-01

    In many social taxa, reproductively dominant individuals sometimes use aggression to secure and maintain reproductive status. In the social insects, queen aggression towards subordinate individuals or workers has been documented and is predicted to occur only in species with a small colony size and a low level of queen-worker dimorphism. We report queen aggression towards reproductive workers in the ant species Aphaenogaster cockerelli, a species with a relatively large colony size and a high level of reproductive dimorphism. Through analysis of cuticular hydrocarbon profiles, we show that queens are aggressive only to reproductively active workers. Non-reproductive workers treated with a hydrocarbon typical for reproductives are attacked by workers but not by queens, which suggests different ways of recognition. We provide possible explanations of why queen aggression is observed in this species.

  16. Chemical profiles, division of labor and social status in Pachycondyla queens (Hymenoptera: Formicidae)

    Science.gov (United States)

    Tentschert, J.; Kolmer, K.; Hölldobler, B.; Bestmann, H.-J.; Delabie, J. H. C.; Heinze, J.

    2001-03-01

    Queens of the neotropical ponerine ant Pachycondyla cf. 'inversa' may co-operate during colony founding. One of several co-founding queens specializes in foraging, whereas the others remain in the nest and guard the brood. Division of labor is achieved by aggressive interactions, which result in the formation of dominance hierarchies. Gas chromatography and mass spectrometry of cuticular hydrocarbons obtained from live queens by SPME revealed consistent differences between the patterns of cuticular hydrocarbons of queens with high versus low rank: only high-ranking queens showed considerable amounts of cuticular pentadecane (n-C15) and heptadecene (n-C17:1). These two substances presumably originate from the queens' Dufour glands.

  17. Eco-evolutionary Red Queen dynamics regulate biodiversity in a metabolite-driven microbial system

    OpenAIRE

    Bonachela, Juan A.; Wortel, Meike T.; Stenseth, Nils Chr.

    2017-01-01

    The Red Queen Hypothesis proposes that perpetual co-evolution among organisms can result from purely biotic drivers. After more than four decades, there is no satisfactory understanding as to which mechanisms trigger Red Queen dynamics or their implications for ecosystem features such as biodiversity. One reason for such a knowledge gap is that typical models are complicated theories where limit cycles represent an idealized Red Queen, and therefore cannot be used to devise experimental setup...

  18. Pheromonal Control of Dealation and Oogenesis in Virgin Queen Fire Ants

    Science.gov (United States)

    Fletcher, David J. C.; Blum, Murray S.

    1981-04-01

    In the fire ant Solenopsis invicta, sexually mature virgin females are prevented from shedding their wings and becoming functional egg layers by the presence of the mated queen. Experimental data suggest that this inhibitory effect results from the action of a relatively nonvolatile primer pheromone (or pheromones) produced by the mated queen and distributed by the workers. Target ants are both virgin queens and workers.

  19. Gender-bias primes elicit queen bee responses among senior policewomen

    OpenAIRE

    Derks, Belle; van Laar, Colette; Ellemers, Naomi; De Groot, Kim

    2011-01-01

    Queen bees are senior women in male-dominated organizations who have achieved success by emphasizing how they differ from other women. Although the behavior of queen bees tends to be seen as contributing to gender disparities in career outcomes, we argue that queen-bee behavior is actually a result of the gender bias and social identity threat that produce gender disparities in career outcomes. In the experiment reported here, we asked separate groups of senior policewomen to recall the prese...

  20. Optoelectronic properties of Black-Silicon generated through inductively coupled plasma (ICP) processing for crystalline silicon solar cells

    Science.gov (United States)

    Hirsch, Jens; Gaudig, Maria; Bernhard, Norbert; Lausch, Dominik

    2016-06-01

    The optoelectronic properties of maskless inductively coupled plasma (ICP) generated black silicon through SF6 and O2 are analyzed by using reflection measurements, scanning electron microscopy (SEM) and quasi steady state photoconductivity (QSSPC). The results are discussed and compared to capacitively coupled plasma (CCP) and industrial standard wet chemical textures. The ICP process forms parabolic like surface structures in a scale of 500 nm. This surface structure reduces the average hemispherical reflection between 300 and 1120 nm up to 8%. Additionally, the ICP texture shows a weak increase of the hemispherical reflection under tilted angles of incidence up to 60°. Furthermore, we report that the ICP process is independent of the crystal orientation and the surface roughness. This allows the texturing of monocrystalline, multicrystalline and kerf-less wafers using the same parameter set. The ICP generation of black silicon does not apply a self-bias on the silicon sample. Therefore, the silicon sample is exposed to a reduced ion bombardment, which reduces the plasma induced surface damage. This leads to an enhancement of the effective charge carrier lifetime up to 2.5 ms at 1015 cm-3 minority carrier density (MCD) after an atomic layer deposition (ALD) with Al2O3. Since excellent etch results were obtained already after 4 min process time, we conclude that the ICP generation of black silicon is a promising technique to substitute the industrial state of the art wet chemical textures in the solar cell mass production.

  1. The evolution of queen control over worker reproduction in the social Hymenoptera.

    Science.gov (United States)

    Olejarz, Jason; Veller, Carl; Nowak, Martin A

    2017-10-01

    A trademark of eusocial insect species is reproductive division of labor, in which workers forego their own reproduction while the queen produces almost all offspring. The presence of the queen is key for maintaining social harmony, but the specific role of the queen in the evolution of eusociality remains unclear. A long-discussed scenario is that a queen either behaviorally or chemically sterilizes her workers. However, the demographic and ecological conditions that enable such manipulation are still debated. We study a simple model of evolutionary dynamics based on haplodiploid genetics. Our model is set in the commonly observed case where workers have lost the ability to lay female (diploid) eggs by mating, but retain the ability to lay male (haploid) eggs. We consider a mutation that acts in a queen, causing her to control the reproductive behavior of her workers. Our mathematical analysis yields precise conditions for the evolutionary emergence and stability of queen-induced worker sterility. These conditions do not depend on the queen's mating frequency. We find that queen control is always established if it increases colony reproductive efficiency, but can evolve even if it decreases colony efficiency. We further derive the conditions under which queen control is evolutionarily stable against invasion by mutant workers who have recovered the ability to lay male eggs.

  2. Natural transmission of feline immunodeficiency virus from infected queen to kitten.

    Science.gov (United States)

    Medeiros, Sheila de Oliveira; Martins, Angelica Nascimento; Dias, Carlos Gabriel Almeida; Tanuri, Amilcar; Brindeiro, Rodrigo de Moraes

    2012-05-25

    Feline immunodeficiency virus (FIV) is a naturally occurring lentivirus that infects cats. The primary mode of transmission occurs through bite wounds, and other routes are difficult to observe in nature. The purpose of this study was to evaluate FIV transmission from queen to kitten in a colony of naturally infected stray cats. With this aim, a queen was monitored over a period of three years. A blood sample was taken to amplify and sequence gag, pol and env regions of the virus from the queen, two kittens and other cats from the colony. Phylogenetic analysis showed evidence of queen to kitten transmission.

  3. Natural transmission of feline immunodeficiency virus from infected queen to kitten

    Directory of Open Access Journals (Sweden)

    Medeiros Sheila de

    2012-05-01

    Full Text Available Abstract Background Feline immunodeficiency virus (FIV is a naturally occurring lentivirus that infects cats. The primary mode of transmission occurs through bite wounds, and other routes are difficult to observe in nature. Findings The purpose of this study was to evaluate FIV transmission from queen to kitten in a colony of naturally infected stray cats. With this aim, a queen was monitored over a period of three years. A blood sample was taken to amplify and sequence gag, pol and env regions of the virus from the queen, two kittens and other cats from the colony. Conclusion Phylogenetic analysis showed evidence of queen to kitten transmission.

  4. Thelytokous parthenogenesis by queens in the dacetine ant Pyramica membranifera (Hymenoptera: Formicidae)

    Science.gov (United States)

    Ito, Fuminori; Touyama, Yoshifumi; Gotoh, Ayako; Kitahiro, Shungo; Billen, Johan

    2010-08-01

    Thelytokous parthenogenesis in which diploid females are produced from unfertilized eggs, was recently reported for some ant species. Here, we document thelytokous reproduction by queens in the polygynous species Pyramica membranifera. Queens that emerged in the laboratory were kept with or without workers under laboratory conditions. Independent colony founding was successful for a few queens if prey was provided. All artificial colonies, which started with a newly emerged queen and workers produced new workers and some of the colonies also produced female sexuals. Some of the female sexuals shed their wings in the laboratory and started formation of new polygynous colonies. Workers had no ovaries and thus, were obligatorily sterile.

  5. Effects of occupational exposure to carbon black on peripheral white blood cell counts and lymphocyte subsets

    NARCIS (Netherlands)

    Dai, Yufei; Niu, Yong; Duan, Huawei; Bassig, Bryan A; Ye, Meng; Zhang, Xiao; Meng, Tao; Bin, Ping; Jia, Xiaowei; Shen, Meili; Zhang, Rong; Hu, Wei; Yang, Xiaofa; Vermeulen, Roel; Silverman, Debra; Rothman, Nathaniel; Lan, Qing; Yu, Shanfa; Zheng, Yuxin

    2016-01-01

    The International Agency for Research on Cancer has classified carbon black (CB) as a possible (Group 2B) human carcinogen. Given that most CB manufacturing processes result in the emission of various types of chemicals, it is uncertain if the adverse health effects that have been observed in

  6. Chemopreventive activity of ellagitannins and their derivatives from black raspberry seeds on HT-29 colon cancer cells.

    Science.gov (United States)

    Cho, Hyunnho; Jung, Hana; Lee, Heejae; Yi, Hae Chang; Kwak, Ho-kyung; Hwang, Keum Taek

    2015-05-01

    Black raspberry (BRB) seeds are a major waste product after fruit processing. The seeds are abundant in ellagitannins (ET), a class of hydrolysable tannins, which are hydrolyzed to ellagic acid (EA) and further metabolized to urolithin A (UA) and urolithin B (UB), known to be bioavailable in the colon and the prostate. In this study, the anti-cancer activities of these compounds were evaluated on HT-29 colon cancer cells. ET, EA, UA and UB inhibited the proliferation of the cancer cells. EA caused a slight, but significant cell cycle arrest at the G1 phase, and urolithins caused cell cycle arrest at the G2/M phase and upregulated p21 expression. Apoptotic cells were detected by Annexin V-FITC/PI assay when treated with the compounds. Disruption in mitochondrial membrane potential and activation of caspases 8 and 9 suggest that both extrinsic and intrinsic apoptotic pathways may be involved. Activation of caspase 3 and cleavage of PARP further confirmed the induction of the apoptosis. ET, EA, UA and UB showed anti-cancer activity by arresting the cell cycle and inducing apoptosis on HT-29 human colon cancer cells. This study suggests that the BRB seeds could be a potential source of anti-cancer ET.

  7. Raman imaging to investigate ultrastructure and composition of plant cell walls : distribution of lignin and cellulose in black spruce wood (Picea mariana)

    Science.gov (United States)

    Umesh P. Agarwal

    2006-01-01

    A detailed understanding of the structural organization of the cell wall of vascular plants is important from both the perspectives of plant biology and chemistry and of commercial utilization. A state-of-the-art 633-nm laser-based confocal Raman microscope was used to determine the distribution of cell wall components in the cross section of black spruce wood in situ...

  8. An Efficient Antioxidant System in a Long-Lived Termite Queen.

    Directory of Open Access Journals (Sweden)

    Eisuke Tasaki

    Full Text Available The trade-off between reproduction and longevity is known in wide variety of animals. Social insect queens are rare organisms that can achieve a long lifespan without sacrificing fecundity. The extended longevity of social insect queens, which contradicts the trade-off, has attracted much attention because it implies the existence of an extraordinary anti-aging mechanism. Here, we show that queens of the termite Reticulitermes speratus incur significantly lower oxidative damage to DNA, protein and lipid and have higher activity of antioxidant enzymes than non-reproductive individuals (workers and soldiers. The levels of 8-hydroxy-2'-deoxyguanosine (oxidative damage marker of DNA were lower in queens than in workers after UV irradiation. Queens also showed lower levels of protein carbonyls and malondialdehyde (oxidative damage markers of protein and lipid, respectively. The antioxidant enzymes of insects are generally composed of catalase (CAT and peroxiredoxin (Prx. Queens showed more than two times higher CAT activity and more than seven times higher expression levels of the CAT gene RsCAT1 than workers. The CAT activity of termite queens was also markedly higher in comparison with other solitary insects and the queens of eusocial Hymenoptera. In addition, queens showed higher expression levels of the Prx gene RsPRX6. These results suggested that this efficient antioxidant system can partly explain why termite queens achieve long life. This study provides important insights into the evolutionary linkage of reproductive division of labor and the development of queens' oxidative stress resistance in social insects.

  9. Improving competitiveness of Daisy.Queen Beauty Salon

    OpenAIRE

    Li, Yan

    2012-01-01

    The purpose of this thesis was to conduct a case study through some surveys and recommendations. The aim of the study was to find competitor‟s advantages, then it could provide recommendations and ways to Daisy.Queen beauty salon to be more attractive and competitive. The theoretical part of thesis include the importance of service, the seven P‟s of service marketing, the importance of service marketing in beauty industry. The seven P‟s of service marketing was analyzed and supported to th...

  10. Modelling information exchange in worker-queen conflict over sex allocation

    NARCIS (Netherlands)

    Pen, I.R.; Taylor, P.D.

    2005-01-01

    We investigate the conflict between queen and worker over sex allocation, specifically the allocation of the queen's eggs between workers and reproductives and the allocation of the reproductive eggs between male and female. In contrast to previous models, we allow workers to observe and use

  11. Queen's researchers make the grade: University boasts two of three finalists for million-dollar grant

    CERN Multimedia

    Armstrong, F E

    2003-01-01

    Two Queen's University researchers are among three Canadian finalists in a contest to win $1 million. Art McDonald, director of the Queen's-run Sudbury Neutrino Observatory Institute, and John Smol, Canada Research Chair in Environmental Change, have been nominated for the Gerhard Herzberg Canada Gold Medal for Science and Engineering (1 page).

  12. Evolutionary genetics of immunological supertypes reveals two faces of the Red Queen.

    Science.gov (United States)

    Lighten, Jackie; Papadopulos, Alexander S T; Mohammed, Ryan S; Ward, Ben J; G Paterson, Ian; Baillie, Lyndsey; Bradbury, Ian R; Hendry, Andrew P; Bentzen, Paul; van Oosterhout, Cock

    2017-11-03

    Red Queen host-parasite co-evolution can drive adaptations of immune genes by positive selection that erodes genetic variation (Red Queen arms race) or results in a balanced polymorphism (Red Queen dynamics) and long-term preservation of genetic variation (trans-species polymorphism). These two Red Queen processes are opposite extremes of the co-evolutionary spectrum. Here we show that both Red Queen processes can operate simultaneously by analysing the major histocompatibility complex (MHC) in guppies (Poecilia reticulata and P. obscura) and swamp guppies (Micropoecilia picta). Sub-functionalisation of MHC alleles into 'supertypes' explains how polymorphisms persist during rapid host-parasite co-evolution. Simulations show the maintenance of supertypes as balanced polymorphisms, consistent with Red Queen dynamics, whereas alleles within supertypes are subject to positive selection in a Red Queen arms race. Building on the divergent allele advantage hypothesis, we show that functional aspects of allelic diversity help to elucidate the evolution of polymorphic genes involved in Red Queen co-evolution.

  13. Secondary queens in the parthenogenetic termite Cavitermes tuberosus develop through a transitional helper stage

    Czech Academy of Sciences Publication Activity Database

    Hellemans, S.; Fournier, D.; Hanus, Robert; Roisin, Y.

    2017-01-01

    Roč. 19, č. 6 (2017), s. 253-262 ISSN 1520-541X Institutional support: RVO:61388963 Keywords : facultative parthenogenesis * replacement queens * termites * asexual queen succession * ontogeny * Cavitermes Subject RIV: EG - Zoology OBOR OECD: Developmental biology Impact factor: 2.243, year: 2016

  14. Effects of honey bee (Apis mellifera L.) queen insemination volume on worker behavior and physiology

    Science.gov (United States)

    Honey bee colonies consist of tens of thousands of workers and a single reproductive queen that produces a pheromone blend which maintains colony organization. Previous studies indicated that the insemination quantity and volume alter queen mandibular pheromone profiles. In our 11-month long field s...

  15. Eco-evolutionary Red Queen dynamics regulate biodiversity in a metabolite-driven microbial system.

    Science.gov (United States)

    Bonachela, Juan A; Wortel, Meike T; Stenseth, Nils Chr

    2017-12-15

    The Red Queen Hypothesis proposes that perpetual co-evolution among organisms can result from purely biotic drivers. After more than four decades, there is no satisfactory understanding as to which mechanisms trigger Red Queen dynamics or their implications for ecosystem features such as biodiversity. One reason for such a knowledge gap is that typical models are complicated theories where limit cycles represent an idealized Red Queen, and therefore cannot be used to devise experimental setups. Here, we bridge this gap by introducing a simple model for microbial systems able to show Red Queen dynamics. We explore diverse biotic sources that can drive the emergence of the Red Queen and that have the potential to be found in nature or to be replicated in the laboratory. Our model enables an analytical understanding of how Red Queen dynamics emerge in our setup, and the translation of model terms and phenomenology into general underlying mechanisms. We observe, for example, that in our system the Red Queen offers opportunities for the increase of biodiversity by facilitating challenging conditions for intraspecific dominance, whereas stasis tends to homogenize the system. Our results can be used to design and engineer experimental microbial systems showing Red Queen dynamics.

  16. case of natural queen succession in a captive colony of naked mole ...

    African Journals Online (AJOL)

    Naked mole-rats occur in large colonies where usually a single queen monopolizes reproduction. Queen succession occurs from within usually as a result of aggressive encounters with subordinate females that queue for reproductive succession following colony instability, which inevitably results in death of either the ...

  17. Dominance and queen succession in captive colonies of the eusocial naked mole-rat, Heterocephalus glaber.

    Science.gov (United States)

    Clarke, F M; Faulkes, C G

    1997-07-22

    Naked mole-rat colonies exhibit a high reproductive skew, breeding being typically restricted to one female (the 'queen') and one to three males. Other colony members are reproductively suppressed, although this suppression can be reversed following the removal or death of the queen. We examined dominance and queen succession within captive colonies to investigate the relationship between urinary testosterone and cortisol, dominance rank and reproductive status; and to determine if behavioural and/or physiological parameters can be used as predictors of queen succession. Social structure was characterized by a linear dominance hierarchy before and after queen removal. Prior to queen removal, dominance rank was negatively correlated with body weight and urinary testosterone and cortisol titres in males and females. Queen removal results in social instability and aggression between high ranking individuals. Dominance rank appears to be a good predictor of reproductive status: queens are the highest ranking colony females and are succeeded by the next highest ranking females. The intense dominance-related aggression that accompanies reproductive succession in naked mole-rats provides empirical support for optimal skew theory.

  18. Grafický design gramofonových alb hudební skupiny Queen

    OpenAIRE

    Bílková, Alena

    2014-01-01

    Bachelor thesis will deal with graphic design of LP covers music group Queen. It will focus on visual studies and LP graphic design in general. The main part will concentrate on music group Queen and graphic design of its LP covers. Powered by TCPDF (www.tcpdf.org)

  19. 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.

  20. Workers and alate queens of Solenopsis geminata share qualitatively similar but quantitatively different venom alkaloid chemistry

    Science.gov (United States)

    The cis and trans alkaloids from body extracts of workers and alate queens of the tropical fire ant, Solenopsis geminata (Hymenoptera: Formicidae), were successfully separated by silica gel chromatography, identified, and quantitated by GC-MS analysis. Both workers and alate queens produce primarily...

  1. Ant Queen Egg-Marking Signals: Matching Deceptive Laboratory Simplicity with Natural Complexity

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Heinze, Jürgen; Boomsma, Jacobus Jan

    2009-01-01

    , and have an excess of longer-chain hydrocarbons. Conclusions Our results suggest that queen egg-marking signals are significantly affected by transfer to the laboratory, and that this change is possibly connected to reduced queen fertility as predicted by honest signaling theory. This change is reflected...... in the worker egg policing response under field and laboratory conditions....

  2. The Queen Bee Phenomenon: Why Women Leaders Distance Themselves from Junior Women

    NARCIS (Netherlands)

    Derks, B.; Van Laar, C.; Ellemers, Naomi

    2016-01-01

    This contribution reviews work on the Queen Bee phenomenon whereby women leaders assimilate into masculine organizations, distance themselves from junior women and legitimize gender inequality in their organization. We propose that rather than being a source of gender inequality, the Queen Bee

  3. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.

    1981-01-01

    This article deals with two questions, namely whether it is possible for black holes to exist, and if the answer is yes, whether we have found any yet. In deciding whether black holes can exist or not the central role in the shaping of our universe played by the forse of gravity is discussed, and in deciding whether we are likely to find black holes in the universe the author looks at the way stars evolve, as well as white dwarfs and neutron stars. He also discusses the problem how to detect a black hole, possible black holes, a southern black hole, massive black holes, as well as why black holes are studied

  4. The geographic mosaic of sex and the Red Queen.

    Science.gov (United States)

    King, Kayla C; Delph, Lynda F; Jokela, Jukka; Lively, Curtis M

    2009-09-15

    The maintenance of sexual reproduction in natural populations is a pressing question for evolutionary biologists. Under the "Red Queen" hypothesis, coevolving parasites reduce the reproductive advantage of asexual reproduction by adapting to infect clonal genotypes after they become locally common. In addition, the "geographic mosaic" theory of coevolution proposes that structured populations of interacting species can produce selection mosaics manifested as coevolutionary "hot spots" and "cold spots". Here, we tested whether a steep, habitat-specific cline in the frequency of sexual reproduction in a freshwater snail could be explained by the existence of hot spots and cold spots for coevolving parasites. We found that the shallow-water margins of lakes, where sexual reproduction is most common, are coevolutionary hot spots, and that deeper habitats are cold spots. These results are consistent with the geographic mosaic theory, in that the intensity of selection resulting from biological interactions can vary sharply in space. The results also support the Red Queen hypothesis, in that sex is associated with coevolutionary hot spots for virulent parasites.

  5. Fantasy under Duress: Connie Scozzaro’s Contrapposto Action Queen

    Directory of Open Access Journals (Sweden)

    Edward Luker

    2017-01-01

    Full Text Available This article explores how Connie Scozzaro’s 'Contrapposto Action Queen (2013' repeatedly takes up two mystifications of femininity from classical mythology, Venus and Lamia, so as to subject them to critique. It takes the images of Venus and Lamia from the writing of two poets, Charles Algernon Swinburne and John Keats. These examples are shown to be epitomes of male poetic fantasy. Within Scozzaro’s collection these fantasies are dissected, undermined, or taken apart through exaggeration, ironization, and the use of tone. The book makes explicit that within patriarchal society, male fantasies are part of a social condition of gendered violence. Contra Brandon Brown’s argument that 'Contrapposto Action Queen' articulates the dialectic of the possible and the actual, this article articulates that for Scozzaro the possible is always conditioned by fantasy. It finishes by looking at Theodor Adorno’s essay ‘Lyric Poetry and Society’. Where Adorno states the lyric subject manifests itself with masculine ‘unrestrained individuation’, this fails to grasp how the lyric poem can utilize strategies of concealment to stress the consequences of the lyric subject’s gendering.

  6. Queen influence on workers behavior of the leaf-cutting ant Atta sexdens rubropilosa (Forel, 1908

    Directory of Open Access Journals (Sweden)

    L. Sousa-Souto

    Full Text Available In an ant colony, the queen is the single reproducer and can interact with her workers via pheromones and cuticular compounds. However, in most species queen importance is not restricted to reproduction: in the initial development of the colony, her presence might play a more important role. In this work, we studied the effects of queen absence on workers behavior displayed in the foraging arena. Ant’s mortality and refuse accumulation was also measured daily. The results showed that queen absence did not alter either workers behavior or foraging efficiency. However, we observed increased ant mortality accompanied by a decrease in refuse dumping outside the nest. These results corroborate the hypothesis that environmental factors are more important than intrinsical factors in the allocation of external tasks. Probably, the queen could only influence internal activities of the colony.

  7. Queen Specific Exocrine Glands in Legionary Ants and Their Possible Function in Sexual Selection.

    Science.gov (United States)

    Hölldobler, Bert

    2016-01-01

    The colonies of army ants and some other legionary ant species have single, permanently wingless queens with massive post petioles and large gasters. Such highly modified queens are called dichthadiigynes. This paper presents the unusually rich exocrine gland endowment of dichthadiigynes, which is not found in queens of other ant species. It has been suggested these kinds of glands produce secretions that attract and maintain worker retinues around queens, especially during migration. However, large worker retinues also occur in non-legionary species whose queens do not have such an exuberance of exocrine glands. We argue and present evidence in support of our previously proposed hypothesis that the enormous outfit of exocrine glands found in dichthadiigynes is due to sexual selection mediated by workers as the main selecting agents.

  8. Queen Specific Exocrine Glands in Legionary Ants and Their Possible Function in Sexual Selection.

    Directory of Open Access Journals (Sweden)

    Bert Hölldobler

    Full Text Available The colonies of army ants and some other legionary ant species have single, permanently wingless queens with massive post petioles and large gasters. Such highly modified queens are called dichthadiigynes. This paper presents the unusually rich exocrine gland endowment of dichthadiigynes, which is not found in queens of other ant species. It has been suggested these kinds of glands produce secretions that attract and maintain worker retinues around queens, especially during migration. However, large worker retinues also occur in non-legionary species whose queens do not have such an exuberance of exocrine glands. We argue and present evidence in support of our previously proposed hypothesis that the enormous outfit of exocrine glands found in dichthadiigynes is due to sexual selection mediated by workers as the main selecting agents.

  9. Functional morphology of the postpharyngeal gland of queens and workers of the ant Monomorium pharaonis (L.)

    DEFF Research Database (Denmark)

    Eelen, Dieter; Børgesen, Lisbeth W.; Billen, Johan

    2006-01-01

    The postpharyngeal gland (PPG) is unique to ants and is the largest exocrine gland in their head. In queens of the pharaoh's ant, Monomorium pharaonis, the gland contains approximately 15 finger-like epithelial extensions on each side and opens dorsolaterally in the posterior pharynx. In these ants...... nurses and foragers. We suggest the PPG serves different purposes in pharaoh's ants: it is likely that the PPG of workers and virgin queens is used to feed larvae. In mated queens the gland probably plays a role in providing the queen with nutritious oils for egg production. The PPG may also function...... their secretion into the gland lumen from an age of 7 days, whereas mated queens accumulate large amounts of secretion in their epithelium. The increasing epithelial thickness, together with the increasing lumen diameter, the presence of numerous inclusions in the epithelium and the release of secretion...

  10. Carcinogenic nitrosamines in traditional beer as the cause of oesophageal squamous cell carcinoma in black South Africans.

    Science.gov (United States)

    Pillay, Viness; Isaacson, Charles; Mothobi, Pride; Hale, Martin; Tomar, Lomas Kumar; Tyagi, Charu; Altini, Mario; Choonara, Yahya Essop; Kumar, Pradeep

    2015-09-21

    Before the 1930s, squamous cell carcinoma (SCC) of the oesophagus was almost unknown among black South Africans. From the 1930s the annual frequency rose. A dietary cause was sought, the staple diet of black people having changed from sorghum to maize (corn), with traditional beer being brewed from maize. Carcinogenic N-nitrosamines in traditional beer were suggested as a cause of SCC of the oesophagus, with Fusarium moniliforme, a corn saprophyte, thought to play a role. To confirm the presence of N-nitrosamines in traditional beer and demonstrate a mechanism for the oncogenesis of oesophageal carcinoma. Analysis by high-performance liquid chromatography was conducted for the identification of nitrosamines in traditional beer samples, and molecular docking studies were employed to predict the affinity between N-nitrosamines and the S100A2 protein. Carcinogenic N-nitrosamines were identified in all six samples of traditional beer examined (N=18 analyses), and docking studies confirmed a high affinity of the nitrosamine N-nitrosopyrrolidone with the S100A2 protein. This may result in the altered expression of the S100A2 protein, leading to tumour progression and prognosis. It is suggested that carcinogenic N-nitrosamines in traditional beer are a major factor in the causation of SCC of the oesophagus in black South Africans. N-nitrosamines have been shown to produce cancer experimentally, but there has not been conclusive epidemiological evidence that N-nitrosamines are carcinogenic to humans. This study is the first to demonstrate the potential link between N-nitrosamines and a human tumour.

  11. 78 FR 56171 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto...

    Science.gov (United States)

    2013-09-12

    ... through June 30. Over the 2009/2010 through 2011/2012 fishing years, an average of 40 fishermen (range of... regulations specifying the queen conch fishing season to correct an inadvertent change to the text that... inadvertent change to the text specifying the queen conch fishing season. Fishing for queen conch is only...

  12. Gigantism in honeybees: Apis cerana queens reared in mixed-species colonies

    Science.gov (United States)

    Tan, Ken; Hepburn, H. R.; He, Shaoyu; Radloff, S. E.; Neumann, P.; Fang, Xiang

    2006-07-01

    The development of animals depends on both genetic and environmental effects to a varying extent. Their relative influences can be evaluated in the social insects by raising the intracolonial diversity to an extreme in nests consisting of workers from more than one species. In this study, we studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the rearing of grafted queen larvae of A. cerana. A. mellifera sealed worker brood was introduced into A. cerana colonies and on emergence, the adults were accepted. Then, A. cerana larvae were grafted for queen rearing into two of these mixed-species colonies. Similarly, A. cerana larvae and A. mellifera larvae were also grafted conspecifically as controls. The success rate of A. cerana queen rearing in the test colonies was 64.5%, surpassing all previous attempts at interspecific queen rearing. After emergence, all virgin queens obtained from the three groups ( N=90) were measured morphometrically. The A. cerana queens from the mixed-species colonies differed significantly in size and pigmentation from the A. cerana control queens and closely approximated the A. mellifera queens. It is inferred that these changes in the A. cerana queens reared in the mixed-species colonies can be attributed to feeding by heterospecific nurse bees and/or chemical differences in royal jelly. Our data show a strong impact of environment on the development of queens. The results further suggest that in honeybees the cues for brood recognition can be learned by heterospecific workers after eclosion, thereby providing a novel analogy to slave making in ants.

  13. Catalytic Enhancement of Carbon Black and Coal-Fueled Hybrid Direct Carbon Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Ippolito, Davide; Kammer Hansen, Kent

    2015-01-01

    , Ce1-xREExO2-δ (REE = Pr, Sm)) and metal oxides (LiMn2O4, Ag2O). Materials showing the highest activity in carbon black (Mn2O3, CeO2, Ce0.6Pr0.4O2-δ, Ag2O) were subsequently tested for catalytic activity toward bituminous coal, as revealed by both I-V-P curves and electrochemical impedance...... spectroscopy (EIS). Catalytic activity was evaluated as a function of various physical characteristics of doped ceria and manganese-based materials....

  14. Optimization of degradation of Reactive Black 5 (RB5) and electricity generation in solar photocatalytic fuel cell system.

    Science.gov (United States)

    Khalik, Wan Fadhilah; Ho, Li-Ngee; Ong, Soon-An; Voon, Chun-Hong; Wong, Yee-Shian; Yusoff, NikAthirah; Lee, Sin-Li; Yusuf, Sara Yasina

    2017-10-01

    The photocatalytic fuel cell (PFC) system was developed in order to study the effect of several operating parameters in degradation of Reactive Black 5 (RB5) and its electricity generation. Light irradiation, initial dye concentration, aeration, pH and cathode electrode are the operating parameters that might give contribution in the efficiency of PFC system. The degradation of RB5 depends on the presence of light irradiation and solar light gives better performance to degrade the azo dye. The azo dye with low initial concentration decolorizes faster compared to higher initial concentration and presence of aeration in PFC system would enhance its performance. Reactive Black 5 rapidly decreased at higher pH due to the higher amount of OH generated at higher pH and Pt-loaded carbon (Pt/C) was more suitable to be used as cathode in PFC system compared to Cu foil and Fe foil. The rapid decolorization of RB5 would increase their voltage output and in addition, it would also increase their V oc , J sc and P max . The breakage of azo bond and aromatic rings was confirmed through UV-Vis spectrum and COD analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. To prevent the occurrence of black water agglomerate through delaying decomposition of cyanobacterial bloom biomass by sediment microbial fuel cell.

    Science.gov (United States)

    Zhou, Yan-Li; Jiang, He-Long; Cai, Hai-Yuan

    2015-04-28

    Settlement of cyanobacterial bloom biomass (CBB) into sediments in eutrophic lakes often induced the occurrence of black water agglomerate and then water quality deterioration. This study investigated the effect of sediment microbial fuel cell (SMFC) on CBB removal in sediments and related water pollution. Sediment bulking and subsequent black water from decomposition of settled CBB happened without SMFC, but were not observed over 100-day experiments with SMFC employment. While CBB in sediments improved power production from SMFC, the removal efficiency of organic matters in CBB-amended sediments with SMFC was significantly lower than that without SMFC. Pyrosequencing analysis showed higher abundances of the fermentative Clostridium and acetoclastic methanogen in CBB-amended bulk sediments without SMFC than with SMFC at the end of experiments. Obviously, SMFC operation changed the microbial community in CBB-amended sediments, and delayed the CBB degradation against sediment bulking. Thus, SMFC could be potentially applied as pollution prevention in CBB-settled and sensitive zones in shallow lakes. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Black silicon with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by mask-less reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Black bus-bars were realized by oxidized copper resulting in reflectance below 3% in the entire visible wavelength range. The combination of these two technologies may result in aesthetic, all-black panels based on conventional, front-contacted solar cells...

  17. Genomic expression differences between cutaneous cells from red hair color individuals and black hair color individuals based on bioinformatic analysis.

    Science.gov (United States)

    Puig-Butille, Joan Anton; Gimenez-Xavier, Pol; Visconti, Alessia; Nsengimana, Jérémie; Garcia-García, Francisco; Tell-Marti, Gemma; Escamez, Maria José; Newton-Bishop, Julia; Bataille, Veronique; Del Río, Marcela; Dopazo, Joaquín; Falchi, Mario; Puig, Susana

    2017-02-14

    The MC1R gene plays a crucial role in pigmentation synthesis. Loss-of-function MC1R variants, which impair protein function, are associated with red hair color (RHC) phenotype and increased skin cancer risk. Cultured cutaneous cells bearing loss-of-function MC1R variants show a distinct gene expression profile compared to wild-type MC1R cultured cutaneous cells. We analysed the gene signature associated with RHC co-cultured melanocytes and keratinocytes by Protein-Protein interaction (PPI) network analysis to identify genes related with non-functional MC1R variants. From two detected networks, we selected 23 nodes as hub genes based on topological parameters. Differential expression of hub genes was then evaluated in healthy skin biopsies from RHC and black hair color (BHC) individuals. We also compared gene expression in melanoma tumors from individuals with RHC versus BHC. Gene expression in normal skin from RHC cutaneous cells showed dysregulation in 8 out of 23 hub genes (CLN3, ATG10, WIPI2, SNX2, GABARAPL2, YWHA, PCNA and GBAS). Hub genes did not differ between melanoma tumors in RHC versus BHC individuals. The study suggests that healthy skin cells from RHC individuals present a constitutive genomic deregulation associated with the red hair phenotype and identify novel genes involved in melanocyte biology.

  18. High-Performance Black Multicrystalline Silicon Solar Cells by a Highly Simplified Metal-Catalyzed Chemical Etching Method

    KAUST Repository

    Ying, Zhiqin

    2016-05-20

    A wet-chemical surface texturing technique, including a two-step metal-catalyzed chemical etching (MCCE) and an extra alkaline treatment, has been proven as an efficient way to fabricate high-efficiency black multicrystalline (mc) silicon solar cells, whereas it is limited by the production capacity and the cost cutting due to the complicated process. Here, we demonstrated that with careful control of the composition in etching solution, low-aspect-ratio bowl-like nanostructures with atomically smooth surfaces could be directly achieved by improved one-step MCCE and with no posttreatment, like alkali solution. The doublet surface texture of implementing this nanobowl structure upon the industrialized acidic-textured surface showed concurrent improvement in optical and electrical properties for realizing 18.23% efficiency mc-Si solar cells (156 mm × 156 mm), which is sufficiently higher than 17.7% of the solely acidic-textured cells in the same batch. The one-step MCCE method demonstrated in this study may provide a cost-effective way to manufacture high-performance mc-Si solar cells for the present photovoltaic industry. © 2016 IEEE.

  19. Black Alcoholism.

    Science.gov (United States)

    Watts, Thomas D.; Wright, Roosevelt

    1988-01-01

    Examines some aspects of the problem of alcoholism among Blacks, asserting that Black alcoholism can best be considered in an ecological, environmental, sociocultural, and public health context. Notes need for further research on alcoholism among Blacks and for action to reduce the problem of Black alcoholism. (NB)

  20. Black Culture

    Science.gov (United States)

    Brown, Angela Khristin

    2013-01-01

    The migration of blacks in North America through slavery became united. The population of blacks passed down a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape…

  1. Differential antennal proteome comparison of adult honeybee drone, worker and queen (Apis mellifera L.).

    Science.gov (United States)

    Fang, Yu; Song, Feifei; Zhang, Lan; Aleku, Dereje Woltedji; Han, Bin; Feng, Mao; Li, Jianke

    2012-01-04

    To understand the olfactory mechanism of honeybee antennae in detecting specific volatile compounds in the atmosphere, antennal proteome differences of drone, worker and queen were compared using 2-DE, mass spectrometry and bioinformatics. Therefore, 107 proteins were altered their expressions in the antennae of drone, worker and queen bees. There were 54, 21 and 32 up-regulated proteins in the antennae of drone, worker and queen, respectively. Proteins upregulated in the drone antennae were involved in fatty acid metabolism, antioxidation, carbohydrate metabolism and energy production, protein folding and cytoskeleton. Proteins upregulated in the antennae of worker and queen bees were related to carbohydrate metabolism and energy production while molecular transporters were upregulated in the queen antennae. Our results explain the role played by the antennae of drone is to aid in perceiving the queen sexual pheromones, in the worker antennae to assist for food search and social communication and in the queen antennae to help pheromone communication with the worker and the drone during the mating flight. This first proteomic study significantly extends our understanding of honeybee olfactory activities and the possible mechanisms played by the antennae in response to various environmental, social, biological and biochemical signals. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  2. Small queens and big-headed workers in a monomorphic ponerine ant

    Science.gov (United States)

    Kikuchi, Tomonori; Miyazaki, Satoshi; Ohnishi, Hitoshi; Takahashi, Junichi; Nakajima, Yumiko; Tsuji, Kazuki

    2008-10-01

    Evolution of caste is a central issue in the biology of social insects. Comparative studies on their morphology so far suggest the following three patterns: (1) a positive correlation between queen worker size dimorphism and the divergence in reproductive ability between castes, (2) a negative correlation among workers between morphological diversity and reproductive ability, and (3) a positive correlation between queen worker body shape difference and the diversity in worker morphology. We conducted morphological comparisons between castes in Pachycondyla luteipes, workers of which are monomorphic and lack their reproductive ability. Although the size distribution broadly overlapped, mean head width, head length, and scape length were significantly different between queens and workers. Conversely, in eye length, petiole width, and Weber’s length, the size differences were reversed. The allometries (head length/head width, scape length/head width, and Weber’s length/head width) were also significantly different between queens and workers. Morphological examinations showed that the body shape was different between queens and workers, and the head part of workers was disproportionately larger than that of queens. This pattern of queen worker dimorphism is novel in ants with monomorphic workers and a clear exception to the last pattern. This study suggests that it is possible that the loss of individual-level selection, the lack of reproductive ability, influences morphological modification in ants.

  3. The interaction of drag queens and gay men in public and private spaces.

    Science.gov (United States)

    Berkowitz, Dana; Belgrave, Linda; Halberstein, Robert A

    2007-01-01

    This study examines the issue of internal segregation within the gay community, focusing on the ways by which the drag queen subculture is distanced from larger mainstream gay society. Through the use of institutional ethnography, symbolic interactionism, and a naturalist approach to sociology, the researchers sought to understand the subjective experience of the drag queen, in particular how drag queens perceive their interactions with mainstream gay society. Data for this study were collected through a series of observations conducted in a variety of spatial contexts and interviews with 18 drag queens. Findings indicate that spatial distance between the drag queens and the mainstream gay men is dependent on both the social context and the level of professionalization of the drag queen. Although drag queens' perceptions of their status in the gay community are also dependent on the latter, discussions of relationship difficulties and the quest for a long-term romantic partner illustrate that discrimination within the gay community is both widespread and complex.

  4. Postmating changes in cuticular chemistry and visual appearance in Ectatomma tuberculatum queens (Formicidae: Ectatomminae)

    Science.gov (United States)

    Hora, Riviane R.; Ionescu-Hirsh, Armin; Simon, Tovit; Delabie, Jacques; Robert, Jacques; Fresneau, Dominique; Hefetz, Abraham

    2008-01-01

    In the ectatommine ant Ectatomma tuberculatum, the visual appearance of queens changes after mating and ovarian development in that their cuticle turns from shiny to matte. In this study, we have shown that this change seems to be caused by 15-fold accumulation of hydrocarbons, in particular heptacosane that covers the multiple grooves present on the cuticular surface creating a wax coat in mated fully fertile queens. Analyses of the scrapped wax revealed that it is composed largely of heptacosane. Peak-by-peak comparison of the cuticular hydrocarbon (CHC) composition of mated, virgin with developed ovaries and virgin with nondeveloped ovaries revealed significant differences between the queen groups. Although the total amount of the CHC of virgin queens with developed ovaries was not higher than virgin queens that did not have developed ovaries, the composition showed a shift toward the mated queen. While it is possible that the large accumulation of hydrocarbons may give extra physical and chemical protection to queens, we propose that the switch in the relative abundance of heptacosane and nonacosane and perhaps of other components is indicative of being a mating and fertility cue. This is the first report in social insects where external chemical changes are accompanied by changes in visual appearance.

  5. Red Queen: from populations to taxa and communities.

    Science.gov (United States)

    Liow, Lee Hsiang; Van Valen, Leigh; Stenseth, Nils Chr

    2011-07-01

    Biotic interactions via the struggle for control of energy and the interactive effects of biota with their physical environment characterize Van Valen's Red Queen (VRQ). Here, we review new evidence for and against a VRQ view of the world from studies of increasing temporal and spatial scales. Interactions among biota and with the physical environment are important for generating and maintaining diversity on diverse timescales, but detailed mechanisms remain poorly understood. We recommend directly estimating the effect of biota and the physical environment on ecological and evolutionary processes. Promising approaches for elucidating VRQ include using mathematical modelling, controlled experimental systems, sampling and processes-oriented approaches for analysing data from natural systems, while paying extra attention to biotic interactions discernable from the fossil record. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. How the Red Queen drives terrestrial mammals to extinction.

    Science.gov (United States)

    Quental, Tiago B; Marshall, Charles R

    2013-07-19

    Most species disappear by the processes of background extinction, yet those processes are poorly understood. We analyzed the evolutionary dynamics of 19 Cenozoic terrestrial mammalian clades with rich fossil records that are now fully extinct or in diversity decline. We find their diversity loss was not just a consequence of "gamblers ruin" but resulted from the evolutionary loss to the Red Queen, a failure to keep pace with a deteriorating environment. Diversity loss is driven equally by both depressed origination rates and elevated extinction rates. Although we find diversity-dependent origination and extinction rates, the diversity of each clade only transiently equaled the implied equilibrium diversity. Thus, the processes that drove diversity loss in terrestrial mammal clades were fundamentally nonequilibrial and overwhelmed diversity-dependent processes.

  7. Queen Cleopatra and the other 'Cleopatras': their medical legacy.

    Science.gov (United States)

    Tsoucalas, Gregory; Kousoulis, Antonis A; Poulakou-Rebelakou, Effie; Karamanou, Marianna; Papagrigoriou-Theodoridou, Maria; Androutsos, George

    2014-05-01

    Cleopatra is a female figure widespread in Greece (especially in Macedonian territory), Egypt and Syria during the Hellenistic era. Ancient women doctors bearing the name Cleopatra have been identified by a systematic search through the ancient Greek, Latin and Egyptian bibliography, including original resources from the first century BC. Fictional and non-fictional figures have been distinguished and their works identified. Queen Cleopatra of Egypt, Galen's physician assistant, the outcast Metrodora, Cleopatra the Alchemist and Cleopatra the Gynaecologist deliver a story of medicine and name-giving that confuses researchers of the past and intrigues those of the present. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  8. Quantifying quantumness and the quest for Queens of Quantum

    International Nuclear Information System (INIS)

    Giraud, Olivier; Braun, Daniel; Braun, Petr

    2010-01-01

    We introduce a measure of 'quantumness' for any quantum state in a finite-dimensional Hilbert space, based on the distance between the state and the convex set of classical states. The latter are defined as states that can be written as a convex sum of projectors onto coherent states. We derive the general properties of this measure of non-classicality and use it to identify, for a given dimension of Hilbert space, the 'Queen of Quantum' (QQ) states, i.e. the most non-classical quantum states. In three dimensions, we obtain the QQ state analytically and show that it is unique up to rotations. In up to 11-dimensional Hilbert spaces, we find the QQ states numerically, and show that in terms of their Majorana representation they are highly symmetric bodies, which for dimensions 5 and 7 correspond to Platonic bodies.

  9. Quantifying quantumness and the quest for Queens of Quantum

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, Olivier; Braun, Daniel [Universite de Toulouse, UPS, Laboratoire de Physique Theorique (IRSAMC), F-31062 Toulouse (France); Braun, Petr, E-mail: olivier.giraud@lptms.u-psud.f [Fachbereich Physik, Universitaet Duisburg-Essen, 47048 Duisburg (Germany)

    2010-06-15

    We introduce a measure of 'quantumness' for any quantum state in a finite-dimensional Hilbert space, based on the distance between the state and the convex set of classical states. The latter are defined as states that can be written as a convex sum of projectors onto coherent states. We derive the general properties of this measure of non-classicality and use it to identify, for a given dimension of Hilbert space, the 'Queen of Quantum' (QQ) states, i.e. the most non-classical quantum states. In three dimensions, we obtain the QQ state analytically and show that it is unique up to rotations. In up to 11-dimensional Hilbert spaces, we find the QQ states numerically, and show that in terms of their Majorana representation they are highly symmetric bodies, which for dimensions 5 and 7 correspond to Platonic bodies.

  10. Tradition and Imitation in Spenser’s The Faerie Queene

    Directory of Open Access Journals (Sweden)

    Jonathan Griffin

    2013-07-01

    Full Text Available The purpose of this paper is to discuss Spenser’s use of imitation as a literary device in his allegorical epic poem The Faerie Queene, originally published in 1590. The paper begins with a synopsis of Spenser’s general intent behind the poem, as well as his use of the theoretical models of literary excellence proposed by his contemporary Sir Phillip Sidney. The paper then follows Spenser’s reinterpretation of Ariosto, his treatment of Virgil and Ovid, and chronicles his attempts to parody these imperious influences to create an epic that would give synthesis to the poetic tradition to which he belonged with his religious ethic and fervent nationalism, while paying tribute to his monarch, Elizabeth I.

  11. Teaching geriatric medicine at the Queen's University of Belfast.

    Science.gov (United States)

    Stout, R W

    1983-01-01

    Undergraduate teaching at the Queen's University, Belfast, takes place in the fourth year of a five year curriculum. It lasts three weeks and this is divided into two parts. First, held within the university department, is topic-based teaching including seminars, discussions, case histories and visits. The second phase of two weeks consists of attachment of two to four students to geriatric medical units both in and outside Belfast. The whole of this module is situated within a combined course involving community medicine, general practice, geriatric medicine and mental health lasting 12 weeks and involving one-third of the year of 150 students each time. In addition to the three weeks teaching in geriatrics, joint discussion groups are held.

  12. Phylogenies reveal new interpretation of speciation and the Red Queen.

    Science.gov (United States)

    Venditti, Chris; Meade, Andrew; Pagel, Mark

    2010-01-21

    The Red Queen describes a view of nature in which species continually evolve but do not become better adapted. It is one of the more distinctive metaphors of evolutionary biology, but no test of its claim that speciation occurs at a constant rate has ever been made against competing models that can predict virtually identical outcomes, nor has any mechanism been proposed that could cause the constant-rate phenomenon. Here we use 101 phylogenies of animal, plant and fungal taxa to test the constant-rate claim against four competing models. Phylogenetic branch lengths record the amount of time or evolutionary change between successive events of speciation. The models predict the distribution of these lengths by specifying how factors combine to bring about speciation, or by describing how rates of speciation vary throughout a tree. We find that the hypotheses that speciation follows the accumulation of many small events that act either multiplicatively or additively found support in 8% and none of the trees, respectively. A further 8% of trees hinted that the probability of speciation changes according to the amount of divergence from the ancestral species, and 6% suggested speciation rates vary among taxa. By comparison, 78% of the trees fit the simplest model in which new species emerge from single events, each rare but individually sufficient to cause speciation. This model predicts a constant rate of speciation, and provides a new interpretation of the Red Queen: the metaphor of species losing a race against a deteriorating environment is replaced by a view linking speciation to rare stochastic events that cause reproductive isolation. Attempts to understand species-radiations or why some groups have more or fewer species should look to the size of the catalogue of potential causes of speciation shared by a group of closely related organisms rather than to how those causes combine.

  13. Asymmetric dispersal and colonization success of Amazonian plant-ants queens.

    Directory of Open Access Journals (Sweden)

    Emilio M Bruna

    Full Text Available The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants.We used empirical data and inverse modeling--a technique developed by plant ecologists to model seed dispersal--to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis having a greater modal distance than two specialists (Pheidole minutula, Azteca sp. that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors.We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the dispersal of ant queens.

  14. Asymmetric Dispersal and Colonization Success of Amazonian Plant-Ants Queens

    Science.gov (United States)

    Bruna, Emilio M.; Izzo, Thiago J.; Inouye, Brian D.; Uriarte, Maria; Vasconcelos, Heraldo L.

    2011-01-01

    Background The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. Methodology/Principal Findings We used empirical data and inverse modeling—a technique developed by plant ecologists to model seed dispersal—to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis) having a greater modal distance than two specialists (Pheidole minutula, Azteca sp.) that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. Conclusions/Significance We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the

  15. Asymmetric dispersal and colonization success of Amazonian plant-ants queens.

    Science.gov (United States)

    Bruna, Emilio M; Izzo, Thiago J; Inouye, Brian D; Uriarte, Maria; Vasconcelos, Heraldo L

    2011-01-01

    The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. We used empirical data and inverse modeling--a technique developed by plant ecologists to model seed dispersal--to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis) having a greater modal distance than two specialists (Pheidole minutula, Azteca sp.) that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the dispersal of ant queens.

  16. Black silicon laser-doped selective emitter solar cell with 18.1% efficiency

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Li, Hongzhao; To, Alexander

    2016-01-01

    We report fabrication of nanostructured, laser-doped selective emitter (LDSE) silicon solar cells with power conversion efficiency of 18.1% and a fill factor (FF) of 80.1%. The nanostructured solar cells were realized through a single step, mask-less, scalable reactive ion etch (RIE) texturing......-texturing as well as the LDSE process, we consider this specific combination a promising candidate for a cost-efficient process for future Si solar cells....

  17. Running with the Red Queen: host-parasite coevolution selects for biparental sex.

    Science.gov (United States)

    Morran, Levi T; Schmidt, Olivia G; Gelarden, Ian A; Parrish, Raymond C; Lively, Curtis M

    2011-07-08

    Most organisms reproduce through outcrossing, even though it comes with substantial costs. The Red Queen hypothesis proposes that selection from coevolving pathogens facilitates the persistence of outcrossing despite these costs. We used experimental coevolution to test the Red Queen hypothesis and found that coevolution with a bacterial pathogen (Serratia marcescens) resulted in significantly more outcrossing in mixed mating experimental populations of the nematode Caenorhabditis elegans. Furthermore, we found that coevolution with the pathogen rapidly drove obligately selfing populations to extinction, whereas outcrossing populations persisted through reciprocal coevolution. Thus, consistent with the Red Queen hypothesis, coevolving pathogens can select for biparental sex.

  18. Neither Worker, Nor Queen: An Ant Caste Specialized in the Production of Unfertilized Eggs

    Directory of Open Access Journals (Sweden)

    J. Heinze

    1995-01-01

    Full Text Available In addition to a queen and workers, colonies of the ant Crematogaster smithi Creighton from Chiricahua Mountains, Arizona, may contain one or several conspicuous “large workers” whose size, external morphology, and number of ovarioles are intermediate between that of queens on one side and that of workers on the other. According to laboratory observations, “large workers” are specialized for the production of unfertilized eggs, which are mainly eaten by the larvae and the queen but may develop into males in queenless colonies. We describe the morphology and the behavior of “large workers” and discuss their evolutionary significance.

  19. The effects of black cohosh on the regulation of estrogen receptor (ERα and progesterone receptor (PR in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Szmyd M

    2018-01-01

    Full Text Available Monica Szmyd,1–3 Victoria Lloyd,1–3 Kelly Hallman,1–3 Katie Aleck,1–3 Viktoria Mladenovik,1–3 Christina McKee,1–3 Mia Morse,1–3 Tyler Bedgood,1–3 Sumi Dinda1–3 1Biomedical and Therapeutic Sciences, School of Health Sciences, 2Prevention Research Center, 3Center of Biomedical Sciences, Oakland University, Rochester, MI, USA Abstract: The North American plant Cimicifuga racemosa, also known as black cohosh (BC, is a herb that recently has gained attention for its hormonal effects. As the usage of hormone replacement therapy is declining due to its adverse effects in women with cancer, many are turning to herbal remedies like BC to treat menopausal symptoms. It is crucial to determine whether the effects of BC involve estrogen receptor-alpha (ERα. Previous studies from our laboratory have shown ERα to be a possible molecular target for BC. In this study, we examined the effects of BC (8% triterpene glycosides alone and in combination with hormones and antihormones on the cellular viability, expression of ERα and progesterone receptor (PR-A/B, and cytolocalization of ERα in ER (+ and PR-A/B (+ T-47D breast cancer cells. Cells were cultured and proteins were extracted and quantified. Western blot analysis revealed alterations in the expression of ERα and PR after treatment with BC (5–100 µM. BC induced a concentration-dependent decrease in ERα and PR protein levels when compared to the control. Image cytometric analysis with propidium iodide staining was used to enumerate changes in T-47D cell number and viability. A decrease in T-47D cell viability was observed upon treatment with 5–100 µM BC. The ideal concentration of BC (100 μM was used in combination with hormones and antihormones in an effort to further understand the possible similarities between this compound and other known effectors of ERα and PR. After a 24-hour concomitant treatment with and/or in combination of BC, estradiol, ICI 182, 780, and Tamoxifen

  20. Carbon black nanoparticles and vascular dysfunction in cultured endothelial cells and artery segments

    DEFF Research Database (Denmark)

    Vesterdal, Lise K; Mikkelsen, Lone; Folkmann, Janne K

    2012-01-01

    surface expression of intercellular cell adhesion molecule 1 (ICAM-1) and vascular adhesion molecule 1 (VCAM-1) in HUVECs at 100µg/ml. CB exposure was also associated with increased reactive oxygen species production and damage to the cell membranes in the form of increased lactate dehydrogenase leakage...

  1. Insights into the dynamics of hind leg development in honey bee (Apis mellifera L. queen and worker larvae - A morphology/differential gene expression analysis

    Directory of Open Access Journals (Sweden)

    Carolina Gonçalves Santos

    2015-09-01

    Full Text Available Phenotypic plasticity is a hallmark of the caste systems of social insects, expressed in their life history and morphological traits. These are best studied in bees. In their co-evolution with angiosperm plants, the females of corbiculate bees have acquired a specialized structure on their hind legs for collecting pollen. In the highly eusocial bees (Apini and Meliponini, this structure is however only present in workers and absent in queens. By means of histological sections and cell proliferation analysis we followed the developmental dynamics of the hind legs of queens and workers in the fourth and fifth larval instars. In parallel, we generated subtractive cDNA libraries for hind leg discs of queen and worker larvae by means of a Representational Difference Analysis (RDA. From the total of 135 unique sequences we selected 19 for RT-qPCR analysis, where six of these were confirmed as differing significantly in their expression between the two castes in the larval spinning stage. The development of complex structures such as the bees’ hind legs, requires diverse patterning mechanisms and signaling modules, as indicated by the set of differentially expressed genes related with cell adhesion and signaling pathways.

  2. Hematopoietic Stem Cell Transplantation in Primary Immunodeficiency Patients in the Black Sea Region of Turkey.

    Science.gov (United States)

    Yıldıran, Alişan; Çeliksoy, Mehmet Halil; Borte, Stephan; Güner, Şükrü Nail; Elli, Murat; Fışgın, Tunç; Özyürek, Emel; Sancak, Recep; Oğur, Gönül

    2017-12-01

    Hematopoietic stem cell transplantation is a promising curative therapy for many combined primary immunodeficiencies and phagocytic disorders. We retrospectively reviewed pediatric cases of patients diagnosed with primary immunodeficiencies and scheduled for hematopoietic stem cell transplantation. We identified 22 patients (median age, 6 months; age range, 1 month to 10 years) with various diagnoses who received hematopoietic stem cell transplantation. The patient diagnoses included severe combined immunodeficiency (n=11), Chediak-Higashi syndrome (n=2), leukocyte adhesion deficiency (n=2), MHC class 2 deficiency (n=2), chronic granulomatous syndrome (n=2), hemophagocytic lymphohistiocytosis (n=1), Wiskott-Aldrich syndrome (n=1), and Omenn syndrome (n=1). Of the 22 patients, 7 received human leukocyte antigen-matched related hematopoietic stem cell transplantation, 12 received haploidentical hematopoietic stem cell transplantation, and 2 received matched unrelated hematopoietic stem cell transplantation. The results showed that 5 patients had graft failure. Fourteen patients survived, yielding an overall survival rate of 67%. Screening newborn infants for primary immunodeficiency diseases may result in timely administration of hematopoietic stem cell transplantation.

  3. Hematopoietic Stem Cell Transplantation in Primary Immunodeficiency Patients in the Black Sea Region of Turkey

    Directory of Open Access Journals (Sweden)

    Alişan Yıldıran

    2017-12-01

    Full Text Available Hematopoietic stem cell transplantation is a promising curative therapy for many combined primary immunodeficiencies and phagocytic disorders. We retrospectively reviewed pediatric cases of patients diagnosed with primary immunodeficiencies and scheduled for hematopoietic stem cell transplantation. We identified 22 patients (median age, 6 months; age range, 1 month to 10 years with various diagnoses who received hematopoietic stem cell transplantation. The patient diagnoses included severe combined immunodeficiency (n=11, Chediak-Higashi syndrome (n=2, leukocyte adhesion deficiency (n=2, MHC class 2 deficiency (n=2, chronic granulomatous syndrome (n=2, hemophagocytic lymphohistiocytosis (n=1, Wiskott-Aldrich syndrome (n=1, and Omenn syndrome (n=1. Of the 22 patients, 7 received human leukocyte antigen-matched related hematopoietic stem cell transplantation, 12 received haploidentical hematopoietic stem cell transplantation, and 2 received matched unrelated hematopoietic stem cell transplantation. The results showed that 5 patients had graft failure. Fourteen patients survived, yielding an overall survival rate of 67%. Screening newborn infants for primary immunodeficiency diseases may result in timely administration of hematopoietic stem cell transplantation.

  4. The effects of black cohosh on the regulation of estrogen receptor (ERα) and progesterone receptor (PR) in breast cancer cells.

    Science.gov (United States)

    Szmyd, Monica; Lloyd, Victoria; Hallman, Kelly; Aleck, Katie; Mladenovik, Viktoria; McKee, Christina; Morse, Mia; Bedgood, Tyler; Dinda, Sumi

    2018-01-01

    The North American plant Cimicifuga racemosa , also known as black cohosh (BC), is a herb that recently has gained attention for its hormonal effects. As the usage of hormone replacement therapy is declining due to its adverse effects in women with cancer, many are turning to herbal remedies like BC to treat menopausal symptoms. It is crucial to determine whether the effects of BC involve estrogen receptor-alpha (ERα). Previous studies from our laboratory have shown ERα to be a possible molecular target for BC. In this study, we examined the effects of BC (8% triterpene glycosides) alone and in combination with hormones and antihormones on the cellular viability, expression of ERα and progesterone receptor (PR)-A/B, and cytolocalization of ERα in ER (+) and PR-A/B (+) T-47D breast cancer cells. Cells were cultured and proteins were extracted and quantified. Western blot analysis revealed alterations in the expression of ERα and PR after treatment with BC (5-100 µM). BC induced a concentration-dependent decrease in ERα and PR protein levels when compared to the control. Image cytometric analysis with propidium iodide staining was used to enumerate changes in T-47D cell number and viability. A decrease in T-47D cell viability was observed upon treatment with 5-100 µM BC. The ideal concentration of BC (100 µM) was used in combination with hormones and antihormones in an effort to further understand the possible similarities between this compound and other known effectors of ERα and PR. After a 24-hour concomitant treatment with and/or in combination of BC, estradiol, ICI 182, 780, and Tamoxifen, downregulation of ERα and PR protein levels was observed. Delineating the role of BC in the regulation of ERα, PR, as well as its mechanisms of action, may be important in understanding the influence of BC on hormone receptors in breast cancer.

  5. Epidemiology of a Daphnia-multiparasite system and its implications for the red queen.

    Science.gov (United States)

    Auld, Stuart K J R; Hall, Spencer R; Duffy, Meghan A

    2012-01-01

    The Red Queen hypothesis can explain the maintenance of host and parasite diversity. However, the Red Queen requires genetic specificity for infection risk (i.e., that infection depends on the exact combination of host and parasite genotypes) and strongly virulent effects of infection on host fitness. A European crustacean (Daphnia magna)--bacterium (Pasteuria ramosa) system typifies such specificity and high virulence. We studied the North American host Daphnia dentifera and its natural parasite Pasteuria ramosa, and also found strong genetic specificity for infection success and high virulence. These results suggest that Pasteuria could promote Red Queen dynamics with D. dentifera populations as well. However, the Red Queen might be undermined in this system by selection from a more common yeast parasite (Metschnikowia bicuspidata). Resistance to the yeast did not correlate with resistance to Pasteuria among host genotypes, suggesting that selection by Metschnikowia should proceed relatively independently of selection by Pasteuria.

  6. Extreme queen-mating frequency and colony fission in African army ants

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; Schoning, Caspar; Pedersen, Jes S

    2004-01-01

    Army ants have long been suspected to represent an independent origin of multiple queen-mating in the social Hymenoptera. Using microsatellite markers, we show that queens of the African army ant Dorylus (Anomma) molestus have the highest absolute (17.3) and effective (17.5) queen......-mating frequencies reported so far for ants. This confirms that obligate multiple queen-mating in social insects is associated with large colony size and advanced social organization, but also raises several novel questions. First, these high estimates place army ants in the range of mating frequencies of honeybees......, which have so far been regarded as odd exceptions within the social Hymenoptera. Army ants and honeybees are fundamentally different in morphology and life history, but are the only social insects known that combine obligate multiple mating with reproduction by colony fission and extremely male...

  7. Mimicry of queen Dufour's gland secretions by workers of Apis mellifera scutellata and A. m. capensis

    Science.gov (United States)

    Sole, Catherine; Kryger, Per; Hefetz, Abraham; Katzav-Gozansky, Tamar; Crewe, Robin

    2002-10-01

    The development of the Dufour's gland of workers of the two honey bee races Apis mellifera scutellata and A. m. capensis was measured. The Dufour's glands of A. m. capensis workers were longer and increased in length more rapidly than the glands of workers of A. m. scutellata at comparable ages. Analysis of the Dufour's gland secretions of workers and queens of both races revealed that there were caste and racial differences. Secretions of queenright A. m. scutellata workers were dominated by a series of long-chain hydrocarbons. In contrast the secretions of the A. m. capensis workers both under queenright and queenless conditions were a mixture of hydrocarbons and wax-type esters, as were those of queens. Multivariate analysis of the secretion profiles indicated that laying workers of both races mimic queens. The secretions of the A. m. capensis laying workers mimicked queen secretions most closely, enabling them to act as successful social parasites.

  8. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae).

    Science.gov (United States)

    Wang, Lei; Zeng, Ling; Chen, Jian

    2015-12-08

    Neonicotinoid insecticides are commonly used in managing pest insects, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicotinoids on S. invicta has never been investigated. In this study, the newly mated queens were fed with water containing 0.01 or 0.25 μg/ml imidacloprid. Imidacloprid at both concentrations did not cause any increase in queen mortality during the founding stage; however, it significantly reduced queens' brood tending ability. In the 0.25 μg/ml imidacloprid treatment, the time to larval emergence was significantly delayed and no pupae or adult workers were produced. This study provides clear evidence that imidacloprid at sublethal concentrations has a significant detrimental impact on S. invicta queens and the development of incipient colonies.

  9. Epidemiology of a Daphnia-multiparasite system and its implications for the red queen.

    Directory of Open Access Journals (Sweden)

    Stuart K J R Auld

    Full Text Available The Red Queen hypothesis can explain the maintenance of host and parasite diversity. However, the Red Queen requires genetic specificity for infection risk (i.e., that infection depends on the exact combination of host and parasite genotypes and strongly virulent effects of infection on host fitness. A European crustacean (Daphnia magna--bacterium (Pasteuria ramosa system typifies such specificity and high virulence. We studied the North American host Daphnia dentifera and its natural parasite Pasteuria ramosa, and also found strong genetic specificity for infection success and high virulence. These results suggest that Pasteuria could promote Red Queen dynamics with D. dentifera populations as well. However, the Red Queen might be undermined in this system by selection from a more common yeast parasite (Metschnikowia bicuspidata. Resistance to the yeast did not correlate with resistance to Pasteuria among host genotypes, suggesting that selection by Metschnikowia should proceed relatively independently of selection by Pasteuria.

  10. 2006 Maryland Department of Natural Resources Lidar: Caroline, Kent and Queen Anne Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Maryland Department of Natural Resources requested the collection of LIDAR data over Kent, Queen Anne and Caroline Counties, MD. In response, EarthData acquired the...

  11. Black Raspberry Extract Increased Circulating Endothelial Progenitor Cells and Improved Arterial Stiffness in Patients with Metabolic Syndrome: A Randomized Controlled Trial.

    Science.gov (United States)

    Jeong, Han Saem; Kim, Sohyeon; Hong, Soon Jun; Choi, Seung Cheol; Choi, Ji-Hyun; Kim, Jong-Ho; Park, Chi-Yeon; Cho, Jae Young; Lee, Tae-Bum; Kwon, Ji-Wung; Joo, Hyung Joon; Park, Jae Hyoung; Yu, Cheol Woong; Lim, Do-Sun

    2016-04-01

    Administration of black raspberry (Rubus occidentalis) is known to improve vascular endothelial function in patients at a high risk for cardiovascular (CV) disease. We investigated short-term effects of black raspberry on circulating endothelial progenitor cells (EPCs) and arterial stiffness in patients with metabolic syndrome. Patients with metabolic syndrome (n = 51) were prospectively randomized into the black raspberry group (n = 26, 750 mg/day) and placebo group (n = 25) during the 12-week follow-up. Central blood pressure, augmentation index, and EPCs, such as CD34/KDR(+), CD34/CD117(+), and CD34/CD133(+), were measured at baseline and at 12-week follow-up. Radial augmentation indexes were significantly decreased in the black raspberry group compared to the placebo group (-5% ± 10% vs. 3% ± 14%, P raspberry group compared to the placebo group (19 ± 109/μL vs. -28 ± 57/μL, P raspberry group compared to the placebo group (-0.5 ± 1.4 pg/mL vs. -0.1 ± 1.1 pg/mL, P raspberry group. The use of black raspberry significantly lowered the augmentation index and increased circulating EPCs, thereby improving CV risks in patients with metabolic syndrome during the 12-week follow-up.

  12. Digest: The Red Queen hypothesis demonstrated by the Daphnia-Caullerya host-parasite system.

    Science.gov (United States)

    Martín-Peciña, María; Osuna-Macaró, Carolina

    2018-01-30

    The Red Queen hypothesis predicts that antagonistic interactions between species lead to coevolutionary change. Turko et al. (2017) used the Daphnia-Caullerya host-parasite system to empirically confirm that the clonal turnover of Daphnia hosts is higher during Caullerya parasite epidemics, as expected under the Red Queen hypothesis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Ant queen egg-marking signals: matching deceptive laboratory simplicity with natural complexity.

    Science.gov (United States)

    van Zweden, Jelle S; Heinze, Jürgen; Boomsma, Jacobus J; d'Ettorre, Patrizia

    2009-01-01

    Experiments under controlled laboratory conditions can produce decisive evidence for testing biological hypotheses, provided they are representative of the more complex natural conditions. However, whether this requirement is fulfilled is seldom tested explicitly. Here we provide a lab/field comparison to investigate the identity of an egg-marking signal of ant queens. Our study was based on ant workers resolving conflict over male production by destroying each other's eggs, but leaving queen eggs unharmed. For this, the workers need a proximate cue to discriminate between the two egg types. Earlier correlative evidence indicated that, in the ant Pachycondyla inversa, the hydrocarbon 3,11-dimethylheptacosane (3,11-diMeC(27)) is more abundant on the surface of queen-laid eggs. We first tested the hypothesis that 3,11-diMeC(27) functions as a queen egg-marking pheromone using laboratory-maintained colonies. We treated worker-laid eggs with synthetic 3,11-diMeC(27) and found that they were significantly more accepted than sham-treated worker-laid eggs. However, we repeated the experiment with freshly collected field colonies and observed no effect of treating worker-laid eggs with 3,11-diMeC(27), showing that this compound by itself is not the natural queen egg-marking pheromone. We subsequently investigated the overall differences of entire chemical profiles of eggs, and found that queen-laid eggs in field colonies are more distinct from worker-laid eggs than in lab colonies, have more variation in profiles, and have an excess of longer-chain hydrocarbons. Our results suggest that queen egg-marking signals are significantly affected by transfer to the laboratory, and that this change is possibly connected to reduced queen fertility as predicted by honest signaling theory. This change is reflected in the worker egg policing response under field and laboratory conditions.

  14. Long-Lived Termite Queens Exhibit High Cu/Zn-Superoxide Dismutase Activity

    Directory of Open Access Journals (Sweden)

    Eisuke Tasaki

    2018-01-01

    Full Text Available In most organisms, superoxide dismutases (SODs are among the most effective antioxidant enzymes that regulate the reactive oxygen species (ROS generated by oxidative energy metabolism. ROS are considered main proximate causes of aging. However, it remains unclear if SOD activities are associated with organismal longevity. The queens of eusocial insects, such as termites, ants, and honeybees, exhibit extraordinary longevity in comparison with the nonreproductive castes, such as workers. Therefore, the queens are promising candidates to study the underlying mechanisms of aging. Here, we found that queens have higher Cu/Zn-SOD activity than nonreproductive individuals of the termite Reticulitermes speratus. We identified three Cu/Zn-SOD sequences and one Mn-SOD sequence by RNA sequencing in R. speratus. Although the queens showed higher Cu/Zn-SOD activity than the nonreproductive individuals, there were no differences in their expression levels of the Cu/Zn-SOD genes RsSOD1 and RsSOD3A. Copper (Cu2+ and Cu+ is an essential cofactor for Cu/Zn-SOD enzyme activity, and the queens had higher concentrations of copper than the workers. These results suggest that the high Cu/Zn-SOD activity of termite queens is related to their high levels of the cofactor rather than gene expression. This study highlights that Cu/Zn-SOD activity contributes to extraordinary longevity in termites.

  15. Intrinsic survival advantage of social insect queens depends on reproductive activation.

    Science.gov (United States)

    Rueppell, O; Königseder, F; Heinze, J; Schrempf, A

    2015-12-01

    The central trade-off between reproduction and longevity dominates most species' life history. However, no mortality cost of reproduction is apparent in eusocial species, particularly social insects in the order Hymenoptera: one or a few individuals (typically referred to as queens) in a group specialize on reproduction and are generally longer lived than all other group members (typically referred to as workers), despite having the same genome. However, it is unclear whether this survival advantage is due to social facilitation by the group or an intrinsic, individual property. Furthermore, it is unknown whether the correlation between reproduction and longevity is due to a direct mechanistic link or an indirect consequence of the social role of the reproductives. To begin addressing these questions, we performed a comparison of queen and worker longevity in the ant Cardiocondyla obscurior under social isolation conditions. Survival of single queens and workers was compared under laboratory conditions, monitoring and controlling for brood production. Our results indicate that there is no intrinsic survival advantage of queens relative to workers unless individuals are becoming reproductively active. This interactive effect of caste and reproduction on life expectancy outside of the normal social context suggests that the positive correlation between reproduction and longevity in social insect queens is due to a direct link that can activate intrinsic survival mechanisms to ensure queen longevity. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  16. Cellular degradation activity is maintained during aging in long-living queen bees.

    Science.gov (United States)

    Hsu, Chin-Yuan; Qiu, Jiantai Timothy; Chan, Yu-Pei

    2016-11-01

    Queen honeybees (Apis mellifera) have a much longer lifespan than worker bees. Whether cellular degradation activity is involved in the longevity of queen bees is unknown. In the present study, cellular degradation activity was evaluated in the trophocytes and oenocytes of young and old queen bees. The results indicated that (i) 20S proteasome activity and the size of autophagic vacuoles decreased with aging, and (ii) there were no significant differences between young and old queen bees with regard to 20S proteasome expression or efficiency, polyubiquitin aggregate expression, microtubule-associated protein 1 light chain 3-II (LC3-II) expression, 70 kDa heat shock cognate protein (Hsc70) expression, the density of autophagic vacuoles, p62/SQSTM1 expression, the activity or density of lysosomes, or molecular target of rapamycin expression. These results indicate that cellular degradation activity maintains a youthful status in the trophocytes and oenocytes of queen bees during aging and that cellular degradation activity is involved in maintaining the longevity of queen bees.

  17. First deliveries after estrus induction using deslorelin and endoscopic transcervical insemination in the queen.

    Science.gov (United States)

    Zambelli, Daniele; Bini, Costanza; Küster, Daniel Gerhard; Molari, Valeria; Cunto, Marco

    2015-09-15

    The present study consists of two distinct parts, experiment 1 and experiment 2. In experiment 1, 13 anestrous queens were treated with a 4.7-mg deslorelin subcutaneous implant to assess its effectiveness in inducing estrus in the domestic cat. Deslorelin is currently used for the reversible suppression of ovarian and testicular activity in dogs and cats and for estrus induction in the bitch. Estrus induction is also reported in the queen but never reported with a targeted study. All the queens showed a positive response to the induction protocol, and estrus was detected within an average of 5.0 ± 2.2 days after the implant placement in 13 out of 13 subjects (100%). Seven of 13 queens exhibited behavioral manifestations of estrus, and the mean number of follicles detected at ultrasound examination was 4.8 ± 1.6 per subject. In experiment 2, three of the queens previously treated with deslorelin for estrus induction were submitted to artificial insemination through endoscopic transcervical catheterization, a new nonsurgical technique for intrauterine sperm deposition. All of them (100%) were pregnant after insemination and they gave birth to healthy litters. The study, as a whole, proves the effectiveness of the 4.7-mg deslorelin subcutaneous implants in inducing estrus in the domestic cat and is, to our knowledge, the first study assessing fertility of the induced estruses. Moreover, it shows the effectiveness of endoscopic transcervical catheterization for artificial insemination in the queen. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Performance of Africanized honeybee colonies settled by queens selected for different traits

    Directory of Open Access Journals (Sweden)

    Tânia Patrícia Schafaschek

    2016-01-01

    Full Text Available We evaluated varroa infestation and the performance of Africanized honeybee colonies with queens selected for honey and royal jelly production, and also unselected queens, correlating with climatic variables. In Campo Alegre, Santa Catarina State, Brazil, the experiment I used 10 Langstroth hives and in Mafra, Santa Catarina State, Brazil, the experiment II was performed with 15 Schenk hives. A mapping in areas of sealed and unsealed brood, honey and pollen was carried out on days zero, 45 and 90 days after the introduction of the queen. In the experiment I, there was interaction between the type of queen selection and the evaluation period for areas of sealed brood, honey, and total stored food. The group selected for royal jelly production presented larger sealed brood area and smaller honey area at 90 days. Varroa infestation was lower (p < 0.05 at 90 days. The type of queen selection and the evaluation period influenced the sealed brood area, the total brood and the total area occupied in the colony. The high relative humidity caused greater honey storage for the local group. The different groups of queens presented different behavior according to the environment in which they are settled.

  19. Gender-bias primes elicit queen-bee responses among senior policewomen.

    Science.gov (United States)

    Derks, Belle; Van Laar, Colette; Ellemers, Naomi; de Groot, Kim

    2011-10-01

    Queen bees are senior women in male-dominated organizations who have achieved success by emphasizing how they differ from other women. Although the behavior of queen bees tends to be seen as contributing to gender disparities in career outcomes, we argue that queen-bee behavior is actually a result of the gender bias and social identity threat that produce gender disparities in career outcomes. In the experiment reported here, we asked separate groups of senior policewomen to recall the presence or absence of gender bias during their careers, and we measured queen-bee responses (i.e., masculine self-descriptions, in-group distancing, and denying of discrimination). Such gender-bias priming increased queen-bee responses among policewomen with low gender identification, but policewomen with high gender identification responded with increased motivation to improve opportunities for other women. These results suggest that gender-biased work environments shape women's behavior by stimulating women with low gender identification to dissociate with other women and to display queen-bee responses as a way to achieve individual mobility.

  20. Does whole-cell pertussis vaccine protect black South African infants?

    African Journals Online (AJOL)

    1991-06-01

    Jun 1, 1991 ... adverse reactions. These are considered the most reactive of childhood vaccines used in routine vaccination schedules, although the possible contribution of the diphtheria and tetanus components of triple vaccines is frequently ignored. Whole- cell vaccines are associated with a wide range of side-effects,.

  1. Greening London's black cabs: a study of driver's preferences for fuel cell taxis

    International Nuclear Information System (INIS)

    Mourato, Susana; Saynor, Bob; Hart, David

    2004-01-01

    Road transport accounts for about a quarter of all carbon emissions in the UK, highlighting the need for low carbon alternatives to current fuels and vehicles. Running on hydrogen and virtually emissions-free, fuel cell vehicles are considered to be one of the most promising ways of reducing transport-related emissions. Understanding the user benefits of fuel cell vehicles and the determinants of demand is essential for their successful penetration. This contingent valuation study investigates the preferences of London taxi drivers for driving emissions-free hydrogen fuel cell taxis, both in the short term as part of a pilot project, and in the longer term if production line fuel cell taxis become available. The results show that willingness to pay to participate in a pilot project seems to be driven mostly by drivers' expectation of personal financial gains. In contrast, however, environmental considerations are found to affect taxi drivers' longer-term vehicle purchasing decisions. The results also reveal that driving hydrogen-fuelled vehicles does not seem to raise safety concerns amongst taxi drivers

  2. Gamma-irradiated black ginseng extract inhibits mast cell degranulation and suppresses atopic dermatitis-like skin lesions in mice.

    Science.gov (United States)

    Kang, Jung Ae; Song, Ha-Yeon; Byun, Eui-Hong; Ahn, Nam-Geun; Kim, Hye-Min; Nam, You Ree; Lee, Gyeong Hee; Jang, Beom-Su; Choi, Dae Seong; Lee, Dong-Eun; Byun, Eui-Baek

    2018-01-01

    Gamma irradiation is able to affect various structural modification and an increase of the biological properties of biomaterials. This study was conducted to investigate the anti-allergenic effect of γ-irradiated black ginseng extract (BGE) using in vitro and in vivo experiments. IgEantigen complex-induced degranulation was measured in RBL-2H3 mast cells. In addition, an anti-atopic dermatitis (AD) test was carried out by spreading γ-irradiated BGE on the dorsal skin of 2,4-dinitrochlorobenzene (DNCB)-induced BALB/c mice. The content of arginylfructose (AF) of gamma-irradiated BGE was higher than that of BGE. In RBL-2H3 mast cells, γ-irradiated BGE treatments significantly reduced the IgE-antigen complex-induced release of β-hexosaminidase, histamine, intracellular ROS, and Ca2+ influx. A western blot analysis showed that γ-irradiated BGE had an inhibitory activity on the FcεRI-mediated signaling in mast cells. In the DNCB-induced AD model, γ-irradiated BGE significantly alleviated the ADlike skin symptoms and clinical signs. The suppression of AD by γ-irradiated BGE was accompanied by a decrease in the serum level of IgE and IL-4, as well as the number of leukocyte. Gamma-irradiated BGE also suppressed IL-4 and increased IFN-γ in splenocytes. Our data suggests that γ-irradiated BGE may be effective therapeutic agents for the treatment of AD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Colony Failure Linked to Low Sperm Viability in Honey Bee (Apis mellifera Queens and an Exploration of Potential Causative Factors.

    Directory of Open Access Journals (Sweden)

    Jeffery S Pettis

    Full Text Available Queen health is closely linked to colony performance in honey bees as a single queen is normally responsible for all egg laying and brood production within the colony. In the U. S. in recent years, queens have been failing at a high rate; with 50% or greater of queens replaced in colonies within 6 months when historically a queen might live one to two years. This high rate of queen failure coincides with the high mortality rates of colonies in the US, some years with >50% of colonies dying. In the current study, surveys of sperm viability in US queens were made to determine if sperm viability plays a role in queen or colony failure. Wide variation was observed in sperm viability from four sets of queens removed from colonies that beekeepers rated as in good health (n = 12; average viability = 92%, were replacing as part of normal management (n = 28; 57%, or where rated as failing (n = 18 and 19; 54% and 55%. Two additional paired set of queens showed a statistically significant difference in viability between colonies rated by the beekeeper as failing or in good health from the same apiaries. Queens removed from colonies rated in good health averaged high viability (ca. 85% while those rated as failing or in poor health had significantly lower viability (ca. 50%. Thus low sperm viability was indicative of, or linked to, colony performance. To explore the source of low sperm viability, six commercial queen breeders were surveyed and wide variation in viability (range 60-90% was documented between breeders. This variability could originate from the drones the queens mate with or temperature extremes that queens are exposed to during shipment. The role of shipping temperature as a possible explanation for low sperm viability was explored. We documented that during shipment queens are exposed to temperature spikes ( 40°C and these spikes can kill 50% or more of the sperm stored in queen spermathecae in live queens. Clearly low sperm viability is

  4. Colony Failure Linked to Low Sperm Viability in Honey Bee (Apis mellifera) Queens and an Exploration of Potential Causative Factors.

    Science.gov (United States)

    Pettis, Jeffery S; Rice, Nathan; Joselow, Katie; vanEngelsdorp, Dennis; Chaimanee, Veeranan

    2016-01-01

    Queen health is closely linked to colony performance in honey bees as a single queen is normally responsible for all egg laying and brood production within the colony. In the U. S. in recent years, queens have been failing at a high rate; with 50% or greater of queens replaced in colonies within 6 months when historically a queen might live one to two years. This high rate of queen failure coincides with the high mortality rates of colonies in the US, some years with >50% of colonies dying. In the current study, surveys of sperm viability in US queens were made to determine if sperm viability plays a role in queen or colony failure. Wide variation was observed in sperm viability from four sets of queens removed from colonies that beekeepers rated as in good health (n = 12; average viability = 92%), were replacing as part of normal management (n = 28; 57%), or where rated as failing (n = 18 and 19; 54% and 55%). Two additional paired set of queens showed a statistically significant difference in viability between colonies rated by the beekeeper as failing or in good health from the same apiaries. Queens removed from colonies rated in good health averaged high viability (ca. 85%) while those rated as failing or in poor health had significantly lower viability (ca. 50%). Thus low sperm viability was indicative of, or linked to, colony performance. To explore the source of low sperm viability, six commercial queen breeders were surveyed and wide variation in viability (range 60-90%) was documented between breeders. This variability could originate from the drones the queens mate with or temperature extremes that queens are exposed to during shipment. The role of shipping temperature as a possible explanation for low sperm viability was explored. We documented that during shipment queens are exposed to temperature spikes ( 40°C) and these spikes can kill 50% or more of the sperm stored in queen spermathecae in live queens. Clearly low sperm viability is linked to

  5. The Red Queen and King in finite populations.

    Science.gov (United States)

    Veller, Carl; Hayward, Laura K; Hilbe, Christian; Nowak, Martin A

    2017-07-03

    In antagonistic symbioses, such as host-parasite interactions, one population's success is the other's loss. In mutualistic symbioses, such as division of labor, both parties can gain, but they might have different preferences over the possible mutualistic arrangements. The rates of evolution of the two populations in a symbiosis are important determinants of which population will be more successful: Faster evolution is thought to be favored in antagonistic symbioses (the "Red Queen effect"), but disfavored in certain mutualistic symbioses (the "Red King effect"). However, it remains unclear which biological parameters drive these effects. Here, we analyze the effects of the various determinants of evolutionary rate: generation time, mutation rate, population size, and the intensity of natural selection. Our main results hold for the case where mutation is infrequent. Slower evolution causes a long-term advantage in an important class of mutualistic interactions. Surprisingly, less intense selection is the strongest driver of this Red King effect, whereas relative mutation rates and generation times have little effect. In antagonistic interactions, faster evolution by any means is beneficial. Our results provide insight into the demographic evolution of symbionts.

  6. Host-parasite 'Red Queen' dynamics archived in pond sediment.

    Science.gov (United States)

    Decaestecker, Ellen; Gaba, Sabrina; Raeymaekers, Joost A M; Stoks, Robby; Van Kerckhoven, Liesbeth; Ebert, Dieter; De Meester, Luc

    2007-12-06

    Antagonistic interactions between hosts and parasites are a key structuring force in natural populations, driving coevolution. However, direct empirical evidence of long-term host-parasite coevolution, in particular 'Red Queen' dynamics--in which antagonistic biotic interactions such as host-parasite interactions can lead to reciprocal evolutionary dynamics--is rare, and current data, although consistent with theories of antagonistic coevolution, do not reveal the temporal dynamics of the process. Dormant stages of both the water flea Daphnia and its microparasites are conserved in lake sediments, providing an archive of past gene pools. Here we use this fact to reconstruct rapid coevolutionary dynamics in a natural setting and show that the parasite rapidly adapts to its host over a period of only a few years. A coevolutionary model based on negative frequency-dependent selection, and designed to mimic essential aspects of our host-parasite system, corroborated these experimental results. In line with the idea of continuing host-parasite coevolution, temporal variation in parasite infectivity changed little over time. In contrast, from the moment the parasite was first found in the sediments, we observed a steady increase in virulence over time, associated with higher fitness of the parasite.

  7. Nan Goldin: da Fotografia do Cotidiano à Visibilidade Drag Queen

    Directory of Open Access Journals (Sweden)

    Vivian Castro de Miranda

    2017-09-01

    Full Text Available Este trabalho tem como objetivo apresentar a biografia da fotógrafa americana Nan Goldin, a partir do recorte de sua produção datada entre as décadas de 1970 e 1990, em que ela fotografou a comunidade drag queen. A partir do cruzamento de informações vigentes em documentário (Série, 2004 e fontes relevantes (Guggenheim Museum, EUA; The Guardian, UK a quem a fotógrafa concedeu entrevistas ou foi notícia, procura-se explorar nesse texto a importância de uma produção que se insere no âmbito de questões caras ao contexto contemporâneo, que é a temática de gênero. Com a perspectiva teórica adotada, baseada principalmente nos apontamentos de Barthes (1984, é possível compreender o corpus analisado como resultante de um olhar sensível para o aspecto humano, com impacto para a discussão e aceitação do grupo social.

  8. Calprotectin in myeloid and epithelial cells of laminae from horses with black walnut extract-induced laminitis.

    Science.gov (United States)

    Faleiros, R R; Nuovo, G J; Belknap, J K

    2009-01-01

    Laminar inflammation is one of the earliest events in equine laminitis. Calprotectin (CP), a Damage-Associated Molecular Pattern protein, is overexpressed in inflammatory conditions of human skin. CP is overexpressed in the laminar epidermis of horses with black walnut extract (BWE)-induced laminitis. Twenty adult horses. Experimental study. Horses were allocated to one of 4 groups. BWE was administered to horses in 3 groups, which were sampled 1.5, 3, and 12 hours (LAM) later. CP was visualized by immunohistochemistry. Laminar leukocyte counts and intensity of laminar epithelial staining were scored for all animals and statistically analyzed. Laminar epidermal CP signal was significantly increased (P= .02) at the LAM time point, compared with other groups. Rare leukocytes were detected in laminae with CP staining in CON group, but there were marked increases in number of leukocytes in BWE-treated groups (P= .003). Sequential hematoxylin and eosin staining demonstrated that the majority of CP-positive leukocytes were perivascular polymorphonuclear neutrophils (PMN) at each of the developmental time points. CP-positive PMN and mononuclear cells were detected in perivascular locations and close to the epidermal basement membrane in the LAM group. CP expression in the laminar epidermis occurs after extravasation of leukocytes, indicating that leukocyte emigration might be an initiating factor in laminar epithelial stress and inflammation in BWE-induced laminitis. These results indicate a possible role of CP in laminitis pathophysiology and laminar failure.

  9. Reactive Black 5 as electron donor and/or electron acceptor in dual chamber of solar photocatalytic fuel cell.

    Science.gov (United States)

    Khalik, Wan Fadhilah; Ho, Li-Ngee; Ong, Soon-An; Voon, Chun-Hong; Wong, Yee-Shian; Yusuf, Sara Yasina; Yusoff, NikAthirah; Lee, Sin-Li

    2018-03-19

    The role of azo dye Reactive Black 5 (RB5) as an electron donor and/or electron acceptor could be distinguished in dual chamber of photocatalytic fuel cell (PFC). The introduction of RB5 in anode chamber increased the voltage generation in the system since degradation of RB5 might produce electrons which also would transfer through external circuit to the cathode chamber. The removal efficiency of RB5 with open and closed circuit was 8.5% and 13.6%, respectively and removal efficiency for open circuit was low due to the fact that recombination of electron-hole pairs might happen in anode chamber since without connection to the cathode, electron cannot be transferred. The degradation of RB5 in cathode chamber with absence of oxygen showed that electrons from anode chamber was accepted by dye molecules to break its azo bond. The presence of oxygen in cathode chamber would improve the oxygen reduction rate which occurred at Platinum-loaded carbon (Pt/C) cathode electrode. The V oc , J sc and P max for different condition of ultrapure water at cathode chamber also affected their fill factor. The transportation of protons to cathode chamber through Nafion membrane could decrease the pH of ultrapure water in cathode chamber and undergo hydrogen evolution reaction in the absence of oxygen which then increased degradation rate of RB5 as well as its electricity generation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Blackberry, raspberry and black raspberry polyphenol extracts attenuate angiotensin II-induced senescence in vascular smooth muscle cells.

    Science.gov (United States)

    Feresin, Rafaela G; Huang, Jingwen; Klarich, DawnKylee S; Zhao, Yitong; Pourafshar, Shirin; Arjmandi, Bahram H; Salazar, Gloria

    2016-10-12

    Activation of angiotensin II (Ang II) signaling during aging increases reactive oxygen species (ROS) leading to vascular senescence, a process linked to the onset and progression of cardiovascular diseases (CVD). Consumption of fruits and vegetables, particularly berries, is associated with decreased incidence of CVD, which has mainly been attributed to the polyphenol content of these foods. Thus, the objective of this study was to investigate the role of blackberry (BL), raspberry (RB), and black raspberry (BRB) polyphenol extracts in attenuating Ang II-induced senescence in vascular smooth muscle cells (VSMCs) and to determine the molecular mechanisms involved. BL, RB and BRB polyphenol extracts (200 μg ml -1 ) attenuated Ang II-induced senescence, denoted by decreased number of cells positive for senescence associated β-galactosidase (SA-β-gal) and down-regulation of p21 and p53 expression, which were associated with decreased ROS levels and Ang II signaling. BL polyphenol extract increased superoxide dismutase (SOD) 1 expression, attenuated the up-regulation of Nox1 expression and the phosphorylation of Akt, p38MAPK and ERK1/2 induced by Ang II, and reduced senescence in response to Nox1 overexpression. In contrast, RB and BRB polyphenol extracts up-regulated the expression of SOD1, SOD2, and glutathione peroxidase 1 (GPx1), but exerted no effect on Nox1 expression nor on senescence induced by Nox1 overexpression. BRB reduced signaling similar to BL, while RB was unable to reduce Akt phosphorylation. Furthermore, we demonstrated that inhibition of Akt, p38MAPK and ERK1/2 as well as down-regulation of Nox1 by siRNA prevented senescence induced by Ang II. Our findings indicate that Ang II-induced senescence is attenuated by BL polyphenols through a Nox1-dependent mechanism and by RB and BRB polyphenols in a Nox1-independent manner, likely by increasing the cellular antioxidant capacity.

  11. Effects of ultraviolet-visible irradiation in the presence of melanin isolated from human black or red hair upon Ehrlich ascites carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Menon, I.A.; Persad, S.; Ranadive, N.S.; Haberman, H.F.

    1983-07-01

    The present study is an attempt to investigate the possibility that ultraviolet irradiation in the presence of pheomelanin may be more harmful to cells than the irradiation in the presence of eumelanin. The effects of UV-visible irradiation upon Ehrlich ascites carcinoma cells in the presence of the melanin isolated from human black hair (eumelanin) or from red hair (pheomelanin) were investigated. Irradiation of these cells was found to produce cell lysis, as observed by leakage of 51Cr from labeled cells and intracellular lactic dehydrogenase from the cells and decrease in cell viability demonstrated by the trypan blue exclusion test. The three parameters were quantitatively parallel to one another under various experimental conditions, namely different periods of irradiation and irradiation in the presence of different concentrations of melanin. The above effects were more pronounced when the irradiation was carried out in the presence of melanin from red hair than in the presence of black-hair melanin. In the absence of either melanin, the irradiation did not produce any significant effect in cell viability or cell lysis. Irradiation of the cells in the presence of red-hair melanin also decreased the transplantability of these cells. These observations clearly show that irradiation of cells in the presence of pheomelanin could produce cytotoxic effects. The present experimental design may have application in the development of in vitro models for the study of UV radiation-induced cutaneous carcinogenesis. The reactions of pheomelanin may be related to the susceptibility of ''Celtic'' skin to UV radiation-induced skin damage and carcinogenesis.

  12. CELL DEATH DIFFERENTIATION IN BLACK HEADED RAMS SPERMATOZOA, USING FLUORESCENT LABELED ANNEXIN V

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    M Ivanova-Kicheva

    2008-11-01

    Full Text Available Double staining kit of Annexin V Cy3.18/6-CFDA was used to investigate the changes in phospholipide asymmetry after treating sperm cells with dexamethasone. The % of spermatozoa with registered translocation of PS in treated with dexamethazone groups at the 10-th min and in control no treated varied from 2.74%±0.65 to 2.30%±0.89. After the 5 hour of incubation these % increased to 39.83±3.33 for the treated group and 23.44±1.12 for the control. It was concluded that Annexin V binding assay is more sensitive in the detection of deterioration in membrane function than other conventional methods such as motility analysis and supravital techniques.

  13. Effect of a fungicide and spray adjuvant on queen-rearing success in honey bees (Hymenoptera: Apidae).

    Science.gov (United States)

    Johnson, Reed M; Percel, Eric G

    2013-10-01

    Commercial producers of honey bee queens (Apis mellifera L.) have reported unexplained loss of immature queens during the larval or pupal stage. Many affected queen-rearing operations are situated among the almond orchards of California and report these losses in weeks after almond trees bloom. Almond flowers are a rich foraging resource for bees, but are often treated with fungicides, insecticides, and spray adjuvants during bloom. Anecdotal reports by queen producers associate problems in queen development with application of the fungicide Pristine (boscalid and pyraclostrobin) and spray adjuvants that are tank-mixed with it. To test the effect of these compounds on queen development, a new bioassay was developed in which queens are reared in closed swarm boxes for 4 d, until capping, with nurse bees fed exclusively on artificially contaminated pollen. Pollen was treated with four concentrations of formulated Pristine (0.4, 4, 40, and 400 ppm), a spray adjuvant (Break-Thru, 200 ppm), the combination of Pristine and spray adjuvant (400:200 ppm), the insect growth regulator insecticide diflubenzuron (100 ppm) as a positive control, or water as negative control. Chemical analysis revealed that low concentrations of pyraclostrobin (50 ppb), but no boscalid, were detectable in royal jelly secreted by nurse bees feeding on treated pollen. No significant difference in queen development or survival was observed between any of the experimental treatments and the negative control. Only diflubenzuron, the positive control, caused a substantial reduction in survival of immature queens.

  14. The effect of queen pheromone status on Varroa mite removal from honey bee colonies with different grooming ability.

    Science.gov (United States)

    Bahreini, Rassol; Currie, Robert W

    2015-07-01

    The objective of this study was to assess the effects of honey bees (Apis mellifera L.) with different grooming ability and queen pheromone status on mortality rates of Varroa mites (Varroa destructor Anderson and Trueman), mite damage, and mortality rates of honey bees. Twenty-four small queenless colonies containing either stock selected for high rates of mite removal (n = 12) or unselected stock (n = 12) were maintained under constant darkness at 5 °C. Colonies were randomly assigned to be treated with one of three queen pheromone status treatments: (1) caged, mated queen, (2) a synthetic queen mandibular pheromone lure (QMP), or (3) queenless with no queen substitute. The results showed overall mite mortality rate was greater in stock selected for grooming than in unselected stock. There was a short term transitory increase in bee mortality rates in selected stock when compared to unselected stock. The presence of queen pheromone from either caged, mated queens or QMP enhanced mite removal from clusters of bees relative to queenless colonies over short periods of time and increased the variation in mite mortality over time relative to colonies without queen pheromone, but did not affect the proportion of damaged mites. The effects of source of bees on mite damage varied with time but damage to mites was not reliably related to mite mortality. In conclusion, this study showed differential mite removal of different stocks was possible under low temperature. Queen status should be considered when designing experiments using bioassays for grooming response.

  15. Myth and memory in the “queen of dreams”

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    Gloria Montero

    2009-06-01

    Full Text Available Aristotle said that where the historian tells us what took place, the poet tells us how it came about. More recently, Gore Vidal defined ‘memoir’ as how one remembers one’s own life as distinct from an autobiography which is history, requiring research into dates and facts which must be double-checked. Memory and Myth play an important role in memoir, allowing the writer to incorporate the real underpinnings of a story that has been lived through rather than simply the account of a sequence of actual events. It might also be argued that the patina of memory that coats the ‘memoir’, as distinct from autobiography, might indeed add its own dimension, taking the account of something very real into a more surreal space. What I call my Rora stories published in Spanish under the title Todas Esas Guerras-- All Those Wars – have never appeared as a collection in English but have been published separately in literary journals. These stories, the very closest I think I will ever come to writing autobiography, grew out of a need to explore my own background – so fragmented in terms of geography, history and culture – at a time when, as a writer, I felt the desperate need to find out exactly who this multicultural person with her mixed baggage might be. The Queen of Dreams, one of the stories in the collection, uses the memory of the child Rora as she attempts to understand the drama and magic of sexuality and love in a grown-up, intolerant world at war. While the story explores the child’s personal history, it also reflects the psyche of Australia at that particular moment.

  16. Black Culture

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    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life.

  17. How Complex, Probable, and Predictable is Genetically Driven Red Queen Chaos?

    Science.gov (United States)

    Duarte, Jorge; Rodrigues, Carla; Januário, Cristina; Martins, Nuno; Sardanyés, Josep

    2015-12-01

    Coevolution between two antagonistic species has been widely studied theoretically for both ecologically- and genetically-driven Red Queen dynamics. A typical outcome of these systems is an oscillatory behavior causing an endless series of one species adaptation and others counter-adaptation. More recently, a mathematical model combining a three-species food chain system with an adaptive dynamics approach revealed genetically driven chaotic Red Queen coevolution. In the present article, we analyze this mathematical model mainly focusing on the impact of species rates of evolution (mutation rates) in the dynamics. Firstly, we analytically proof the boundedness of the trajectories of the chaotic attractor. The complexity of the coupling between the dynamical variables is quantified using observability indices. By using symbolic dynamics theory, we quantify the complexity of genetically driven Red Queen chaos computing the topological entropy of existing one-dimensional iterated maps using Markov partitions. Co-dimensional two bifurcation diagrams are also built from the period ordering of the orbits of the maps. Then, we study the predictability of the Red Queen chaos, found in narrow regions of mutation rates. To extend the previous analyses, we also computed the likeliness of finding chaos in a given region of the parameter space varying other model parameters simultaneously. Such analyses allowed us to compute a mean predictability measure for the system in the explored region of the parameter space. We found that genetically driven Red Queen chaos, although being restricted to small regions of the analyzed parameter space, might be highly unpredictable.

  18. Red Queen dynamics in multi-host and multi-parasite interaction system.

    Science.gov (United States)

    Rabajante, Jomar F; Tubay, Jerrold M; Uehara, Takashi; Morita, Satoru; Ebert, Dieter; Yoshimura, Jin

    2015-04-22

    In host-parasite systems, dominant host types are expected to be eventually replaced by other hosts due to the elevated potency of their specific parasites. This leads to changes in the abundance of both hosts and parasites exhibiting cycles of alternating dominance called Red Queen dynamics. Host-parasite models with less than three hosts and parasites have been demonstrated to exhibit Red Queen cycles, but natural host-parasite interactions typically involve many host and parasite types resulting in an intractable system with many parameters. Here we present numerical simulations of Red Queen dynamics with more than ten hosts and specialist parasites under the condition of no super-host nor super-parasite. The parameter region where the Red Queen cycles arise contracts as the number of interacting host and parasite types increases. The interplay between inter-host competition and parasite infectivity influences the condition for the Red Queen dynamics. Relatively large host carrying capacity and intermediate rates of parasite mortality result in never-ending cycles of dominant types.

  19. Running with the Red Queen: the role of biotic conflicts in evolution.

    Science.gov (United States)

    Brockhurst, Michael A; Chapman, Tracey; King, Kayla C; Mank, Judith E; Paterson, Steve; Hurst, Gregory D D

    2014-12-22

    What are the causes of natural selection? Over 40 years ago, Van Valen proposed the Red Queen hypothesis, which emphasized the primacy of biotic conflict over abiotic forces in driving selection. Species must continually evolve to survive in the face of their evolving enemies, yet on average their fitness remains unchanged. We define three modes of Red Queen coevolution to unify both fluctuating and directional selection within the Red Queen framework. Empirical evidence from natural interspecific antagonisms provides support for each of these modes of coevolution and suggests that they often operate simultaneously. We argue that understanding the evolutionary forces associated with interspecific interactions requires incorporation of a community framework, in which new interactions occur frequently. During their early phases, these newly established interactions are likely to drive fast evolution of both parties. We further argue that a more complete synthesis of Red Queen forces requires incorporation of the evolutionary conflicts within species that arise from sexual reproduction. Reciprocally, taking the Red Queen's perspective advances our understanding of the evolution of these intraspecific conflicts.

  20. Red Queen Processes Drive Positive Selection on Major Histocompatibility Complex (MHC) Genes.

    Science.gov (United States)

    Ejsmond, Maciej Jan; Radwan, Jacek

    2015-11-01

    Major Histocompatibility Complex (MHC) genes code for proteins involved in the incitation of the adaptive immune response in vertebrates, which is achieved through binding oligopeptides (antigens) of pathogenic origin. Across vertebrate species, substitutions of amino acids at sites responsible for the specificity of antigen binding (ABS) are positively selected. This is attributed to pathogen-driven balancing selection, which is also thought to maintain the high polymorphism of MHC genes, and to cause the sharing of allelic lineages between species. However, the nature of this selection remains controversial. We used individual-based computer simulations to investigate the roles of two phenomena capable of maintaining MHC polymorphism: heterozygote advantage and host-pathogen arms race (Red Queen process). Our simulations revealed that levels of MHC polymorphism were high and driven mostly by the Red Queen process at a high pathogen mutation rate, but were low and driven mostly by heterozygote advantage when the pathogen mutation rate was low. We found that novel mutations at ABSs are strongly favored by the Red Queen process, but not by heterozygote advantage, regardless of the pathogen mutation rate. However, while the strong advantage of novel alleles increased the allele turnover rate, under a high pathogen mutation rate, allelic lineages persisted for a comparable length of time under Red Queen and under heterozygote advantage. Thus, when pathogens evolve quickly, the Red Queen is capable of explaining both positive selection and long coalescence times, but the tension between the novel allele advantage and persistence of alleles deserves further investigation.

  1. Sequential palynostratigraphy of the Queen City and Weches formations (Middle Eocene Claiborne Group), southeast central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Elsik, W.C. (MycoStrat Connection, Houston, TX (United States))

    1993-02-01

    Palynomorph sequences of several orders of magnitude were found in the Queen City and Weches formations respectively at Six Mile and Burleson bluffs on the Brazos River, Milam and Burleson counties, Texas. The long term development of the subtropical to tropical Claibornian palynoflora included Engelhardtia spp., Friedrichipollis claibornensis, Nudopollis terminalis, Pollenites laesius and Symplocoipollenites spp. Shorter term fluctuations in sea level were reflected by common herbaceous pollen in the Queen City, and common mangrove pollen in the Weches. Paleoenvironments were marginally to fully marine; dinocysts occurred throughout. The Wetzeliella group of dinocysts were present only in the Queen City at Six Mile Bluff. Late Paleocene to Early Eocene pollen, and Early Middle Eocene pollen with last effective occurrences near the Queen City and Weches boundary included Aesculiidites circumstriatus, Annona foveoreticulata and a new species of Platycarya. Five short term warmer-cooler couplet events were represented by successive abundance peaks of Juglandaceae followed by Ulmus; Alnus supports the three upper Ulmus peaks. One deep water event was recorded by an abundance of fresh water Pediastrum at the Queen City and Weches boundary. That boundary event was bracketed by two of the Alnus and Ulmus peaks.

  2. Wintering Reserve Queens in Mini-Plus and 3-Comb Nuclei

    Directory of Open Access Journals (Sweden)

    Siuda Maciej

    2014-06-01

    Full Text Available The aim of this study was to develop an effective method of overwintering reserve honey bee queens in two-storey mini-plus mating nuclei and in 3-comb nuclei (frames 36 x 26 cm, Wielkopolski hive. The assay was performed during three wintering seasons (2005 - 2008 parallel at two centers in Poland: the Division of Apiculture at the University of Life Sciences (SGGW in Warsaw, and the Apiculture Division at the University of Warmia and Mazury (UWM in Olsztyn. The results showed that 59% of queens overwintered in mini-plus nuclei and 77% in 3-comb nuclei. Among queens in mini-plus nuclei 63% overwintered in bee yard and only 55% in cellar. Within queens in 3-comb nuclei, 62% overwintered in Olsztyn and 91% in Warsaw. The highest survival rate of 93% was observed in Warsaw during the first season. Due to low survival rate, it is not recommended to overwinter the queens in miniplus nuclei.

  3. Winged queens replaced by reproductives smaller than workers in Mystrium ants

    Science.gov (United States)

    Molet, Mathieu; Peeters, Christian; Fisher, Brian L.

    2007-04-01

    In ants, winged queens that are specialized for independent colony foundation can be replaced by wingless reproductives better adapted for colony fission. We studied this shift in reproductive strategy by comparing two Mystrium species from Madagascar using morphometry, allometry and dissections. Mystrium rogeri has a single dealate queen in each colony with a larger thorax than workers and similar mandibles that allow these queens to hunt during non-claustral foundation. In contrast, Mystrium ‘red’ lacks winged queens and half of the female adults belong to a wingless ‘intermorph’ caste smaller and allometrically distinct from the workers. Intermorphs have functional ovaries and spermatheca while those of workers are degenerate. Intermorphs care for brood and a few mate and reproduce making them an all-purpose caste that takes charge of both work and reproduction. However, their mandibles are reduced and inappropriate for hunting centipedes, unlike the workers’ mandibles. This together with their small thorax disallow them to perform independent colony foundation, and colonies reproduce by fission. M. rogeri workers have mandibles polymorphic in size and shape, which allow for all tasks from brood care to hunting. In M. ‘red’, colonial investment in reproduction has shifted from producing expensive winged queens to more numerous helpers. M. ‘red’ intermorphs are the first case of reproductives smaller than workers in ants and illustrate their potential to diversify their caste system for better colonial economy.

  4. The Effect of Open Brood and Colony Strength on the Onset of Oviposition by Queen Bees

    Directory of Open Access Journals (Sweden)

    Gąbka Jakub

    2014-06-01

    Full Text Available In bee colonies without open brood, e.g., after swarming, there is no need for royal jelly, and nurse bees thus do not produce it. According to many beekeepers, adding combs with open brood restarts the production of royal jelly by nurse bees, and the virgin queens then are better fed and start earlier oviposition. The purpose of this study was to investigate whether the presence of open brood and the strength of the colonies affect the onset of oviposition by queen bees. Open brood in colonies with virgins before and during mating flights did not accelerate the initiation of oviposition by the queens. In addition, no differences were identified in starting oviposition by queens in strong colonies of more than 30,000 worker bees, or in weak colonies with up to 1,000 workers. Overall, the results showed that neither open brood in the nests, nor the strength of the colonies affects the onset of oviposition by queen bees.

  5. Red Queen Processes Drive Positive Selection on Major Histocompatibility Complex (MHC Genes.

    Directory of Open Access Journals (Sweden)

    Maciej Jan Ejsmond

    2015-11-01

    Full Text Available Major Histocompatibility Complex (MHC genes code for proteins involved in the incitation of the adaptive immune response in vertebrates, which is achieved through binding oligopeptides (antigens of pathogenic origin. Across vertebrate species, substitutions of amino acids at sites responsible for the specificity of antigen binding (ABS are positively selected. This is attributed to pathogen-driven balancing selection, which is also thought to maintain the high polymorphism of MHC genes, and to cause the sharing of allelic lineages between species. However, the nature of this selection remains controversial. We used individual-based computer simulations to investigate the roles of two phenomena capable of maintaining MHC polymorphism: heterozygote advantage and host-pathogen arms race (Red Queen process. Our simulations revealed that levels of MHC polymorphism were high and driven mostly by the Red Queen process at a high pathogen mutation rate, but were low and driven mostly by heterozygote advantage when the pathogen mutation rate was low. We found that novel mutations at ABSs are strongly favored by the Red Queen process, but not by heterozygote advantage, regardless of the pathogen mutation rate. However, while the strong advantage of novel alleles increased the allele turnover rate, under a high pathogen mutation rate, allelic lineages persisted for a comparable length of time under Red Queen and under heterozygote advantage. Thus, when pathogens evolve quickly, the Red Queen is capable of explaining both positive selection and long coalescence times, but the tension between the novel allele advantage and persistence of alleles deserves further investigation.

  6. Tolerating an infection: an indirect benefit of co-founding queen associations in the ant Lasius niger

    Science.gov (United States)

    Pull, Christopher D.; Hughes, William O. H.; Brown, Mark J. F.

    2013-12-01

    Pathogens exert a strong selection pressure on organisms to evolve effective immune defences. In addition to individual immunity, social organisms can act cooperatively to produce collective defences. In many ant species, queens have the option to found a colony alone or in groups with other, often unrelated, conspecifics. These associations are transient, usually lasting only as long as each queen benefits from the presence of others. In fact, once the first workers emerge, queens fight to the death for dominance. One potential advantage of co-founding may be that queens benefit from collective disease defences, such as mutual grooming, that act against common soil pathogens. We test this hypothesis by exposing single and co-founding queens to a fungal parasite, in order to assess whether queens in co-founding associations have improved survival. Surprisingly, co-foundresses exposed to the entomopathogenic fungus Metarhizium did not engage in cooperative disease defences, and consequently, we find no direct benefit of multiple queens on survival. However, an indirect benefit was observed, with parasite-exposed queens producing more brood when they co-founded, than when they were alone. We suggest this is due to a trade-off between reproduction and immunity. Additionally, we report an extraordinary ability of the queens to tolerate an infection for long periods after parasite exposure. Our study suggests that there are no social immunity benefits for co-founding ant queens, but that in parasite-rich environments, the presence of additional queens may nevertheless improve the chances of colony founding success.

  7. Black Cohosh

    Science.gov (United States)

    ... who have had hormone-sensitive conditions such as breast cancer or for pregnant women or nursing mothers. Black cohosh should not be confused with blue cohosh (Caulophyllum thalictroides) , which has different effects and may not be safe. Black cohosh has ...

  8. Contrasting roles for CD4 vs. CD8 T-cells in a murine model of virally induced "T1 black hole" formation.

    Science.gov (United States)

    Pirko, Istvan; Chen, Yi; Lohrey, Anne K; McDole, Jeremiah; Gamez, Jeffrey D; Allen, Kathleen S; Pavelko, Kevin D; Lindquist, Diana M; Dunn, R Scott; Macura, Slobodan I; Johnson, Aaron J

    2012-01-01

    MRI is sensitive to tissue pathology in multiple sclerosis (MS); however, most lesional MRI findings have limited correlation with disability. Chronic T1 hypointense lesions or "T1 black holes" (T1BH), observed in a subset of MS patients and thought to represent axonal damage, show moderate to strong correlation with disability. The pathogenesis of T1BH remains unclear. We previously reported the first and as of yet only model of T1BH formation in the Theiler's murine encephalitis virus induced model of acute CNS neuroinflammation induced injury, where CD8 T-cells are critical mediators of axonal damage and related T1BH formation. The purpose of this study was to further analyze the role of CD8 and CD4 T-cells through adoptive transfer experiments and to determine if the relevant CD8 T-cells are classic epitope specific lymphocytes or different subsets. C57BL/6 mice were used as donors and RAG-1 deficient mice as hosts in our adoptive transfer experiments. In vivo 3-dimensional MRI images were acquired using a 7 Tesla small animal MRI system. For image analysis, we used semi-automated methods in Analyze 9.1; transfer efficiency was monitored using FACS of brain infiltrating lymphocytes. Using a peptide depletion method, we demonstrated that the majority of CD8 T-cells are classic epitope specific cytotoxic cells. CD8 T-cell transfer successfully restored the immune system's capability to mediate T1BH formation in animals that lack adaptive immune system, whereas CD4 T-cell transfer results in an attenuated phenotype with significantly less T1BH formation. These findings demonstrate contrasting roles for these cell types, with additional evidence for a direct pathogenic role of CD8 T-cells in our model of T1 black hole formation.

  9. Contrasting roles for CD4 vs. CD8 T-cells in a murine model of virally induced "T1 black hole" formation.

    Directory of Open Access Journals (Sweden)

    Istvan Pirko

    Full Text Available MRI is sensitive to tissue pathology in multiple sclerosis (MS; however, most lesional MRI findings have limited correlation with disability. Chronic T1 hypointense lesions or "T1 black holes" (T1BH, observed in a subset of MS patients and thought to represent axonal damage, show moderate to strong correlation with disability. The pathogenesis of T1BH remains unclear. We previously reported the first and as of yet only model of T1BH formation in the Theiler's murine encephalitis virus induced model of acute CNS neuroinflammation induced injury, where CD8 T-cells are critical mediators of axonal damage and related T1BH formation. The purpose of this study was to further analyze the role of CD8 and CD4 T-cells through adoptive transfer experiments and to determine if the relevant CD8 T-cells are classic epitope specific lymphocytes or different subsets. C57BL/6 mice were used as donors and RAG-1 deficient mice as hosts in our adoptive transfer experiments. In vivo 3-dimensional MRI images were acquired using a 7 Tesla small animal MRI system. For image analysis, we used semi-automated methods in Analyze 9.1; transfer efficiency was monitored using FACS of brain infiltrating lymphocytes. Using a peptide depletion method, we demonstrated that the majority of CD8 T-cells are classic epitope specific cytotoxic cells. CD8 T-cell transfer successfully restored the immune system's capability to mediate T1BH formation in animals that lack adaptive immune system, whereas CD4 T-cell transfer results in an attenuated phenotype with significantly less T1BH formation. These findings demonstrate contrasting roles for these cell types, with additional evidence for a direct pathogenic role of CD8 T-cells in our model of T1 black hole formation.

  10. Social and genetic structure of a supercolonial weaver ant, Polyrhachis robsoni, with dimorphic queens

    DEFF Research Database (Denmark)

    Van Zweden, Jelle Stijn; Carew, Melissa E.; Henshaw, Michael T.

    2007-01-01

    reduction of the former. Aggression tests showed that hostility between ants from different nests was minimal. Nests frequently contained numbers of both queen types, with microgynes about twice as numerous as macrogynes. Nestmate workers, microgynes, and macrogynes, were significantly related to others...... within their caste, with macrogynes more highly related than the other castes. Relatedness values between these groups of nestmates were also significant. Pairwise relatedness values were consistent with both queen morphs producing workers. At the population level, microgynes from different nests were...... also significantly related and there was a weak inverse relationship between pairwise relatedness value between individuals and distance between nests.We conclude that this species is supercolonial and that the two queen morphs are part of the same population....

  11. Relic excavated in western India is probably of Georgian Queen Ketevan.

    Science.gov (United States)

    Rai, Niraj; Taher, Nizamuddin; Singh, Manvendra; Chaubey, Gyaneshwer; Jha, Aditya Nath; Singh, Lalji; Thangaraj, Kumarasamy

    2014-01-01

    History has well documented the execution of Queen Ketevan of Georgia by the Persian Emperor of modern day Iran. Based on historical records, in 1624 two Augustinian friars unearthed the queen's remains and one of them brought the relic to the St. Augustine convent in Goa, India. We carried out ancient DNA analysis on the human bone remains excavated from the St. Augustine convent by sequencing and genotyping of the mitochondrial DNA. The investigations of the remains revealed a unique mtDNA haplogroup U1b, which is absent in India, but present in Georgia and surrounding regions. Since our genetic analysis corroborates archaeological and literary evidence, it is likely that the excavated bone belongs to Queen Ketevan of Georgia. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Gene expression profiling reveals effects of Cimicifuga racemosa (L.) NUTT. (black cohosh) on the estrogen receptor positive human breast cancer cell line MCF-7

    Science.gov (United States)

    Gaube, Friedemann; Wolfl, Stefan; Pusch, Larissa; Kroll, Torsten C; Hamburger, Matthias

    2007-01-01

    Background Extracts from the rhizome of Cimicifuga racemosa (black cohosh) are increasingly popular as herbal alternative to hormone replacement therapy (HRT) for the alleviation of postmenopausal disorders. However, the molecular mode of action and the active principles are presently not clear. Previously published data have been largely contradictory. We, therefore, investigated the effects of a lipophilic black cohosh rhizome extract and cycloartane-type triterpenoids on the estrogen receptor positive human breast cancer cell line MCF-7. Results Both extract and purified compounds clearly inhibited cellular proliferation. Gene expression profiling with the extract allowed us to identify 431 regulated genes with high significance. The extract induced expression pattern differed from those of 17β-estradiol or the estrogen receptor antagonist tamoxifen. We observed a significant enrichment of genes in an anti-proliferative and apoptosis-sensitizing manner, as well as an increase of mRNAs coding for gene products involved in several stress response pathways. These functional groups were highly overrepresented among all regulated genes. Also several transcripts coding for oxidoreductases were induced, as for example the cytochrome P450 family members 1A1 and 1B1. In addition, some transcripts associated with antitumor but also tumor-promoting activity were regulated. Real-Time RT-PCR analysis of 13 selected genes was conducted after treatment with purified compounds – the cycloartane-type triterpene glycoside actein and triterpene aglycons – showing similar expression levels compared to the extract. Conclusion No estrogenic but antiproliferative and proapoptotic gene expression was shown for black cohosh in MCF-7 cells at the transcriptional level. The effects may be results of the activation of different pathways. The cycloartane glycosides and – for the first time – their aglycons could be identified as an active principle in black cohosh. PMID:17880733

  13. Facultative use of thelytokous parthenogenesis for queen production in the polyandrous ant Cataglyphis cursor.

    Science.gov (United States)

    Doums, C; Cronin, A L; Ruel, C; Fédérici, P; Haussy, C; Tirard, C; Monnin, T

    2013-07-01

    The evolutionary paradox of sex remains one of the major debates in evolutionary biology. The study of species capable of both sexual and asexual reproduction can elucidate factors important in the evolution of sex. One such species is the ant Cataglyphis cursor, where the queen maximizes the transmission of her genes by producing new queens (gynes) asexually while simultaneously maintaining a genetically diverse workforce via the sexual production of workers. We show that the queen can also produce gynes sexually and may do so to offset the costs of asexual reproduction. We genotyped 235 gynes from 18 colonies and found that half were sexually produced. A few colonies contained both sexually and asexually produced gynes. Although workers in this species can also use thelytoky, we found no evidence of worker production of gynes based on genotypes of 471 workers from the six colonies producing sexual gynes. Gynes are thus mainly, and potentially exclusively, produced by the queen. Simulations of gynes inbreeding level following one to ten generations of automictic thelytoky suggest that the queen switches between or combines thelytoky and sex, which may reduce the costs of inbreeding. This is supported by the relatively small size of inbred gynes in one colony, although we found no relationship between the level of inbreeding and immune parameters. Such facultative use of sex and thelytoky by individual queens contrasts with other known forms of parthenogenesis in ants, which are typically characterized by distinct lineages specializing in one strategy or the other. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  14. Maternal mortality at Queen Elizabeth Central Hospital, 1989 to 1990.

    Science.gov (United States)

    Wiebenga, J E

    1992-04-01

    An obstetrician examined records of all maternal deaths that occurred in the Chatinkha Maternity Wing of Queen Elizabeth Central Hospital in Blantyre, Malawi, during 1989-1990. None of the deaths were caused by conditions unrelated to pregnancy. In 1989 there were 78 maternal deaths out of 14,272 live births (a maternal mortality ratio of 546/100,000 live births). In 1990 there were 73 maternal deaths out of 14,281 live births (a maternal mortality ratio of 511/100,000 live births). In each year, 37 women died directly from complications of pregnancy, delivery, or their management. In 1989, the leading cause of maternal death was postabortal sepsis (15 cases), followed by obstructed labor (8 cases) and puerperal sepsis (6 cases). In 1990, the leading causes were puerperal sepsis (13 cases) and postabortal sepsis (10 cases). The number of HIV-seropositive women among direct maternal deaths was 8 for both years. In 1990, the cesarean section rate was 6.5%. Women who had undergone a cesarean section faced a risk of puerperal sepsis-related death 8.5 times greater than that of women who had delivered vaginally. The 1990 mortality rate among induced abortion cases may have been as high as 8%. There were 41 and 36 indirect maternal deaths in 1989 and 1990, respectively. The leading causes of indirect maternal death were fever (8 cases) and bacterial meningitis (5 cases). The cause could not be determined in 15 cases. By 1990, the leading causes of indirect maternal death were bacterial meningitis (8 cases) and AIDS (6 cases). 5 of the 8 bacterial meningitis cases tested positive for HIV. The 4 patients with tuberculosis and 3 patients with septicemia were HIV positive. 41% and 56% of maternal deaths in 1989 and 1990, respectively, were avoidable. When one excluded uncertain avoidable factors, 21% and 45% of maternal deaths could not be avoided. The leading avoidable factors were deficient hospital care (18 cases), patient's delay (12 cases), and illegal abortion (10

  15. 76 FR 82413 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-12-30

    ... Atmospheric Administration 50 CFR Part 622 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral... Administration 50 CFR Part 622 [Docket No. 101217620-1788-03] RIN 0648-BA62 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates Fishery Management Plans of...

  16. Report of species diagnosis of a tuna at Queens Products B.V. on 23 December 2009

    NARCIS (Netherlands)

    Couperus, A.S.

    2009-01-01

    According to a company in the same marketsegment as Queen Products B.V. part of the tuna filet sold by Queens Products B.V. does not consist of the species that is mentioned on the label. According to DNA analysis filets were not from the species on the label, Albacore (Thunnus alalunga), but from

  17. Behavioral Differentiation and Ovarian Development of Unmated Gynes, Queens, and Workers of Ectatomma vizottoi Almeida 1987 (Formicidae, Ectatomminae

    Directory of Open Access Journals (Sweden)

    Alexsandro Santana Vieira

    2012-01-01

    Full Text Available Behavioral differentiation and ovarian development of unmated gynes, queens, and workers of Ectatomma vizottoi were investigated in laboratory conditions. Forty-one behavioral acts were identified and quantified for workers, 19 for queens and 24 for unmated gynes, for an overall species repertoire of 42 different behavioral acts. Ovipositing reproductive eggs was an exclusive task of the queen, whereas workers showed 15 caste-specific behaviors. The most important (frequent behaviors for the queens were brood care, immobility, and reproduction, and for workers were immobility, grooming/interaction, brood care, and foraging. Unmated gynes (not winged primarily showed immobility, brood care, grooming/interaction, and foraging. Analysis of ovarian development showed that unmated gynes had little-developed ovarioles, in contrast to queens. Queens and unmated gynes showed a clear behavioral differentiation, in which queens played the role of reproducers and unmated gynes performed activities belonging to the worker repertoire. Despite the presence of several breeding queens in the colony, functional monogyny was the rule.

  18. 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...

  19. Queen-worker caste ratio depends on colony size in the pharaoh ant (Monomorium pharaonis)

    DEFF Research Database (Denmark)

    Schmidt, Anna Mosegaard; Linksvayer, Timothy Arnold; Boomsma, Jacobus Jan

    2011-01-01

    affecting this variable remain scarcely studied. Maintaining polygynous pharaoh ant (Monomorium pharaonis) colonies in the laboratory has provided us with the opportunity to experimentally manipulate colony size, one of the key factors that can be expected to affect colony level queen–worker caste ratios......The success of an ant colony depends on the simultaneous presence of reproducing queens and nonreproducing workers in a ratio that will maximize colony growth and reproduction. Despite its presumably crucial role, queen–worker caste ratios (the ratio of adult queens to workers) and the factors...

  20. To and From the Queen: Modalities of Epistolography in the Correspondence of Elizabeth I

    Directory of Open Access Journals (Sweden)

    Giuliana Iannaccaro

    2014-04-01

    Full Text Available The article analyses the connection between modalities of letter writing and the relation between writer and addressee. We take into consideration the case of Elizabeth I of England, situated in the overall panorama of early modern European historiography. The English Queen was a prolific and skilful letter writer, endowed with an uncommon talent for foreign languages; but she was also, thanks to her role, the willing or unwilling recipient of thousands of epistles. By selecting two different corpora of letters, from and to the Queen, it is possible to explore how personal relations, degree of acquaintance, respective status and purpose of the letter influence the very structure of the genre.

  1. INFLUENCE OF HONEYBEE QUEENS ORIGIN TO THE PRODUCTION CHARACTERISTICS OF CARNIOLAN BEES (APIS MELLIFERA CARNICA IN SLOVENIA

    Directory of Open Access Journals (Sweden)

    J POKLUKAR

    2002-05-01

    Full Text Available Total amount of 4.355 records of honeybee colonies production characteristics was estimated on the 251 bee yards in Slovenia from 1993 to 2001. Queens were produced on 29 queen producing yards. The average lsmeans of honey yields increased by 0,41 kg a year. The swarming behaviour and the defensive behaviour of bees increased as well by - 0,091 points, and –0,038 points respectively. According to the last two years records, the honey yields of bee colonies were significantly influenced by the drone gene pool at queen production yards. The swarming behaviour was in contrary more influenced by the queen mothers on queen production yards. The defensive behaviour of bee colonies and the daily varroa mite fall were not significantly influenced by parents.

  2. Synergistic Activity of Deguelin and Fludarabine in Cells from Chronic Lymphocytic Leukemia Patients and in the New Zealand Black Murine Model.

    Directory of Open Access Journals (Sweden)

    Nerea Rebolleda

    Full Text Available B-cell chronic lymphocytic leukemia (CLL remains an incurable disease, and despite the improvement achieved by therapeutic regimes developed over the last years still a subset of patients face a rather poor prognosis and will eventually relapse and become refractory to therapy. The natural rotenoid deguelin has been shown to induce apoptosis in several cancer cells and cell lines, including primary human CLL cells, and to act as a chemopreventive agent in animal models of induced carcinogenesis. In this work, we show that deguelin induces apoptosis in vitro in primary human CLL cells and in CLL-like cells from the New Zealand Black (NZB mouse strain. In both of them, deguelin dowregulates AKT, NFκB and several downstream antiapoptotic proteins (XIAP, cIAP, BCL2, BCL-XL and survivin, activating the mitochondrial pathway of apoptosis. Moreover, deguelin inhibits stromal cell-mediated c-Myc upregulation and resistance to fludarabine, increasing fludarabine induced DNA damage. We further show that deguelin has activity in vivo against NZB CLL-like cells in an experimental model of CLL in young NZB mice transplanted with spleen cells from aged NZB mice with lymphoproliferation. Moreover, the combination of deguelin and fludarabine in this model prolonged the survival of transplanted mice at doses of both compounds that were ineffective when administered individually. These results suggest deguelin could have potential for the treatment of human CLL.

  3. Trichomicosis pubis: black variety.

    OpenAIRE

    Neri, I; Frassetto, A; Pasquinelli, G; Patrizi, A

    1994-01-01

    A case of a 25 year old man with the black variety of trichomicosis pubis is presented on account of its extreme rareity. Scanning electron microscopy confirms that trichomicosis pubis is caused by bacterial colonisation of the pubic hair and shows that bacteria are able to penetrate cuticular horny cells directly through their free plasma membrane.

  4. Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase

    Directory of Open Access Journals (Sweden)

    Edypo Jacob Silva

    2014-12-01

    Full Text Available Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase. This study evaluated the crude protein content of queens of Atta sexdens before the nuptial flight and after the claustral phase in laboratory and field colonies. The hypothesis was that protein is used for survival of the queen and for early colony growth during the claustral phase. Additionally, the nest morphology, live biomass and adult population of field colonies were evaluated. Crude protein was determined by digestion of the organic material with sulfuric acid at high temperatures. The mean crude protein content was 123.23 ± 11.20 mg for females before the nuptial flight and 70.44 ± 12.21 mg for laboratory-reared queens after the claustral phase. The post-claustral crude protein content of field-collected queen was 55.90 ± 9.18 mg. With respect to the loss of crude protein as a function of duration of the claustral phase, laboratory-reared queens lost 52.79 mg and field-collected queens lost 67.33 mg compared to females before the nuptial flight. A positive linear correlation was observed between the weight of field-collected queens (256.4 ± 36.3 mg and colony biomass (13.02 ± 9.12 g, but there was no correlation between biomass and nest depth (13.11 ± 3.82 cm. As expected, the present results support the hypothesis that protein is used for survival of the queen and for early colony growth, as demonstrated by the reduction in crude protein content as a function of duration of the claustral phase. To our knowledge, this is the first study to provide data of the dynamics of protein reserves in leaf-cutting ant queens during the claustral phase.

  5. Black Tea

    Science.gov (United States)

    ... leaves of the same plant, has some different properties. Black tea is used for improving mental alertness ... that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen ( ...

  6. A 6-year-long manipulation with soil warming and canopy nitrogen additions does not affect xylem phenology and cell production of mature black spruce

    Directory of Open Access Journals (Sweden)

    Madjelia Cangre Ebou eDAO

    2015-11-01

    Full Text Available The predicted climate warming and increased atmospheric inorganic nitrogen deposition are expected to have dramatic impacts on plant growth. However, the extent of these effects and their interactions remains unclear for boreal forest trees. The aim of this experiment was to investigate the effects of increased soil temperature and nitrogen (N depositions on stem intra-annual growth of two mature stands of black spruce [Picea mariana (Mill. BSP] in Quebec, Canada. During 2008-2013, the soil around mature trees was warmed up by 4 °C with heating cables during the growing season and precipitations containing three times the current inorganic N concentration were added by frequent canopy applications. Xylem phenology and cell production were monitored weekly from April to October. The 6-year-long experiment performed in two sites at different altitude showed no substantial effect of warming and N-depositions on xylem phenological phases of cell enlargement, wall thickening and lignification. Cell production, in terms of number of tracheids along the radius, also did not differ significantly and followed the same patterns in control and treated trees. These findings allowed the hypothesis of a medium-term effect of soil warming and N depositions on the growth of mature black spruce to be rejected.

  7. Volunteering as Red Queen mechanism for cooperation in public goods games

    DEFF Research Database (Denmark)

    Hauert, C.; De Monte, Silvia; Hofbauer, J.

    2002-01-01

    under very diverse assumptions on population structure and adaptation mechanisms, leading usually not to an equilibrium but to an unending cycle of adjustments (a Red Queen type of evolution). Thus, voluntary participation offers an escape hatch out of some social traps. Cooperation can subsist...

  8. Host-parasite Red Queen dynamics with phase-locked rare genotypes.

    Science.gov (United States)

    Rabajante, Jomar F; Tubay, Jerrold M; Ito, Hiromu; Uehara, Takashi; Kakishima, Satoshi; Morita, Satoru; Yoshimura, Jin; Ebert, Dieter

    2016-03-01

    Interactions between hosts and parasites have been hypothesized to cause winnerless coevolution, called Red Queen dynamics. The canonical Red Queen dynamics assume that all interacting genotypes of hosts and parasites undergo cyclic changes in abundance through negative frequency-dependent selection, which means that any genotype could become frequent at some stage. However, this prediction cannot explain why many rare genotypes stay rare in natural host-parasite systems. To investigate this, we build a mathematical model involving multihost and multiparasite genotypes. In a deterministic and controlled environment, Red Queen dynamics occur between two genotypes undergoing cyclic dominance changes, whereas the rest of the genotypes remain subordinate for long periods of time in phase-locked synchronized dynamics with low amplitude. However, introduction of stochastic noise in the model might allow the subordinate cyclic host and parasite types to replace dominant cyclic types as new players in the Red Queen dynamics. The factors that influence such evolutionary switching are interhost competition, specificity of parasitism, and degree of stochastic noise. Our model can explain, for the first time, the persistence of rare, hardly cycling genotypes in populations (for example, marine microbial communities) undergoing host-parasite coevolution.

  9. The turning points in the solution of n-queens problem using ...

    African Journals Online (AJOL)

    We also observed that, using a set of even and odd numbers, the odd number experience a turning point before the even numbers. The algorithm of the standard backtracking method was implemented in C programming language and, we used Microsoft Notepad as our output file to display the arrangement of the queens.

  10. 78 FR 67086 - Safety Zone, Submarine Cable Replacement Operations, Kent Island Narrows; Queen Anne's County, MD

    Science.gov (United States)

    2013-11-08

    ... 1625-AA00 Safety Zone, Submarine Cable Replacement Operations, Kent Island Narrows; Queen Anne's County... vessels on navigable waters during submarine cable replacement operations at the Kent Island Narrows (MD... involves the installation of a submarine cable within a federal navigation channel requiring divers, a...

  11. Morphometric Identification of Queens, Workers and Intermediates in In Vitro Reared Honey Bees (Apis mellifera).

    Science.gov (United States)

    De Souza, Daiana A; Wang, Ying; Kaftanoglu, Osman; De Jong, David; Amdam, Gro V; Gonçalves, Lionel S; Francoy, Tiago M

    2015-01-01

    In vitro rearing is an important and useful tool for honey bee (Apis mellifera L.) studies. However, it often results in intercastes between queens and workers, which are normally are not seen in hive-reared bees, except when larvae older than three days are grafted for queen rearing. Morphological classification (queen versus worker or intercastes) of bees produced by this method can be subjective and generally depends on size differences. Here, we propose an alternative method for caste classification of female honey bees reared in vitro, based on weight at emergence, ovariole number, spermatheca size and size and shape, and features of the head, mandible and basitarsus. Morphological measurements were made with both traditional morphometric and geometric morphometrics techniques. The classifications were performed by principal component analysis, using naturally developed queens and workers as controls. First, the analysis included all the characters. Subsequently, a new analysis was made without the information about ovariole number and spermatheca size. Geometric morphometrics was less dependent on ovariole number and spermatheca information for caste and intercaste identification. This is useful, since acquiring information concerning these reproductive structures requires time-consuming dissection and they are not accessible when abdomens have been removed for molecular assays or in dried specimens. Additionally, geometric morphometrics divided intercastes into more discrete phenotype subsets. We conclude that morphometric geometrics are superior to traditional morphometrics techniques for identification and classification of honey bee castes and intermediates.

  12. Queen regulates biogenic amine level and nestmate recognition in workers of the fire ant, Solenopsis invicta

    Science.gov (United States)

    Vander Meer, Robert K.; Preston, Catherine A.; Hefetz, Abraham

    2008-12-01

    Nestmate recognition is a critical element in social insect organization, providing a means to maintain territoriality and close the colony to parasites and predators. Ants detect the colony chemical label via their antennae and respond to the label mismatch of an intruder with aggressive behavior. In the fire ant, Solenopsis invicta, worker ability to recognize conspecific nonnestmates decreases if the colony queen is removed, such that they do not recognize conspecific nonnestmates as different. Here, we tested the hypothesis that the presence of the colony queen influences the concentration of octopamine, a neuromodulator, in worker ants, which in turn has an effect on nestmate recognition acuity in workers. We demonstrate that queenless workers exhibit reduced brain octopamine levels and reduced discriminatory acuteness; however, feeding queenless workers octopamine restored both. Dopamine levels are influenced by honeybee queen pheromones; however, levels of this biogenic amine were unchanged in our experiments. This is the first demonstration of a link between the presence of the colony queen, a worker biogenic amine, and conspecific nestmate recognition, a powerful expression of colony cohesion and territoriality.

  13. Variability in size at maturity and reproductive season of queen conch Lobatus gigas (Gastropoda

    NARCIS (Netherlands)

    Boman, Erik Maitz; Graaf, de Martin; Nagelkerke, Leopold A.J.; Stoner, Allan W.; Bissada, Caroline E.; Avila-Poveda, Omar Hernando; Baqueiro-Cardenas, Erick Raul; Smaal, Aad C.

    2018-01-01

    Queen conch (Lobatus gigas), is an economically and culturally important marine gastropod. The species is subject to extensive exploitation throughout large parts of the Caribbean which has led to a decrease in population densities across much of the species’ distribution range. Hence, there is a

  14. A phylogenetic test of the Red Queen Hypothesis: outcrossing and parasitism in the Nematode phylum.

    Science.gov (United States)

    Gibson, Amanda Kyle; Fuentes, Jesualdo Arturo

    2015-02-01

    Sexual outcrossing is costly relative to selfing and asexuality, yet it is ubiquitous in nature, a paradox that has long puzzled evolutionary biologists. The Red Queen Hypothesis argues that outcrossing is maintained by antagonistic interactions between host and parasites. Most tests of this hypothesis focus on the maintenance of outcrossing in hosts. The Red Queen makes an additional prediction that parasitic taxa are more likely to be outcrossing than their free-living relatives. We test this prediction in the diverse Nematode phylum using phylogenetic comparative methods to evaluate trait correlations. In support of the Red Queen, we demonstrate a significant correlation between parasitism and outcrossing in this clade. We find that this correlation is driven by animal parasites, for which outcrossing is significantly enriched relative to both free-living and plant parasitic taxa. Finally, we test hypotheses for the evolutionary history underlying the correlation of outcrossing and animal parasitism. Our results demonstrate that selfing and asexuality are significantly less likely to arise on parasitic lineages than on free-living ones. The findings of this study are consistent with the Red Queen Hypothesis. Moreover, they suggest that the maintenance of genetic variation is an important factor in the persistence of parasitic lineages. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  15. Krobo Queen Mothers: Gender, Power, and Contemporary Female Traditional Authority in Ghana

    NARCIS (Netherlands)

    Steegstra, M.

    2009-01-01

    This article focuses on the emergence and performance of Krobo queen mothers in Southern Ghana. It seeks to highlight the significance of female traditional rulers in contemporary Ghana and fill gaps in knowledge about their position in patrilineal societies. Whereas it is often assumed that their

  16. The Red Queen hypothesis and geographical parthenogenesis in the alpine hawkweed Hieracium alpinum (Asteraceae)

    Czech Academy of Sciences Publication Activity Database

    Hartmann, M.; Štefánek, M.; Zdvořák, P.; Heřman, P.; Chrtek, Jindřich; Mráz, P.

    2017-01-01

    Roč. 122, č. 4 (2017), s. 681-696 ISSN 0024-4066 Institutional support: RVO:67985939 Keywords : apomixis * polyploidy * Red Queen hypothesis Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 2.288, year: 2016

  17. Queens University of Charlotte--Myers Park Traditional Elementary School Partnership

    Science.gov (United States)

    Horn, Suzanne E.; Wooten-Thornburg, Amy; Bonner, Paul; Boyd, Irma; Gerald, Jamie; Perkins, Shavonn; Mercer, Elizabeth; Hunter, Laura

    2010-01-01

    Great work can be accomplished with little budgets and big dreams and desires for increased student achievement. The focus of the Queens University of Charlotte and Myers Park Traditional School (MPTS) partnership was excellent teacher development that centered on learning as a community of teachers (both pre-service and in-service). What they…

  18. Asymmetric ecological conditions favor Red-Queen type of continued evolution over stasis.

    Science.gov (United States)

    Nordbotten, Jan Martin; Stenseth, Nils C

    2016-02-16

    Four decades ago, Leigh Van Valen presented the Red Queen's hypothesis to account for evolution of species within a multispecies ecological community [Van Valen L (1973) Evol Theory 1(1):1-30]. The overall conclusion of Van Valen's analysis was that evolution would continue even in the absence of abiotic perturbations. Stenseth and Maynard Smith presented in 1984 [Stenseth NC, Maynard Smith J (1984) Evolution 38(4):870-880] a model for the Red Queen's hypothesis showing that both Red-Queen type of continuous evolution and stasis could result from a model with biotically driven evolution. However, although that contribution demonstrated that both evolutionary outcomes were possible, it did not identify which ecological conditions would lead to each of these evolutionary outcomes. Here, we provide, using a simple, yet general population-biologically founded eco-evolutionary model, such analytically derived conditions: Stasis will predominantly emerge whenever the ecological system contains only symmetric ecological interactions, whereas both Red-Queen and stasis type of evolution may result if the ecological interactions are asymmetrical, and more likely so with increasing degree of asymmetry in the ecological system (i.e., the more trophic interactions, host-pathogen interactions, and the like there are [i.e., +/- type of ecological interactions as well as asymmetric competitive (-/-) and mutualistic (+/+) ecological interactions]). In the special case of no between-generational genetic variance, our results also predict dynamics within these types of purely ecological systems.

  19. The making of a queen: TOR pathway is a key player in diphenic caste development.

    Directory of Open Access Journals (Sweden)

    Avani Patel

    2007-06-01

    Full Text Available Honey bees (Apis mellifera provide a principal example of diphenic development. Excess feeding of female larvae results in queens (large reproductives. Moderate diet yields workers (small helpers. The signaling pathway that links provisioning to female developmental fate is not understood, yet we reasoned that it could include TOR (target of rapamycin, a nutrient- and energy-sensing kinase that controls organismal growth.Here, the role of Apis mellifera TOR (amTOR in caste determination is examined by rapamycin/FK506 pharmacology and RNA interference (RNAi gene knockdown. We show that in queen-destined larvae, the TOR inhibitor rapamycin induces the development of worker characters that are blocked by the antagonist FK506. Further, queen fate is associated with elevated activity of the Apis mellifera TOR encoding gene, amTOR, and amTOR gene knockdown blocks queen fate and results in individuals with worker morphology.A much-studied insect dimorphism, thereby, can be governed by the TOR pathway. Our results present the first evidence for a role of TOR in diphenic development, and suggest that adoption of this ancestral nutrient-sensing cascade is one evolutionary pathway for morphological caste differentiation in social insects.

  20. Age-dependent changes in the chemistry of exocrine glands of Bombus terrestris queens

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Klára; Cahlíková, L.; Hovorka, Oldřich; Ptáček, L.; Valterová, Irena

    2008-01-01

    Roč. 34, č. 4 (2008), s. 458-466 ISSN 0098-0331 R&D Projects: GA MŠk 2B06007; GA AV ČR IAA4055403 Institutional research plan: CEZ:AV0Z40550506 Keywords : Bombus terrestris * bumblebee queens * sex pheromone Subject RIV: CC - Organic Chemistry Impact factor: 2.327, year: 2008

  1. Exocrine gland secretions of virgin queens of five Bumblebee species (Hymenoptera: Apidae, Bombini)

    Czech Academy of Sciences Publication Activity Database

    Cahlíková, L.; Hovorka, Oldřich; Ptáček, V.; Valterová, Irena

    2004-01-01

    Roč. 59, - (2004), s. 582-589 ISSN 0939-5075 R&D Projects: GA ČR GA203/02/0158 Institutional research plan: CEZ:AV0Z4055905 Keywords : bombus * virgin queens * sex pheromone Subject RIV: CC - Organic Chemistry Impact factor: 0.715, year: 2004

  2. Effect of Growth Media on Rooting of Queen of the Philippine ...

    African Journals Online (AJOL)

    Data generated were subjected to analysis of variance, significant of treatment means was tested using least significant difference at 5% level and correlation analysis was carried out. The result shows that, variety had significant (P< 0.05) effect on rooting characteristics of (Queen of the Philippines (Mussaenda philippica),

  3. Red Queen Takes White Knight: The Commercialisation of Accounting Education in Australia

    Directory of Open Access Journals (Sweden)

    Graham Bowrey

    2015-09-01

    Full Text Available This paper investigates the adaptive and maladaptive consequences of changes resulting from the commercialisation of Australian universities, specifically their accounting schools, and aims to identify the organisational changes triggered by competition that affect the growth of universities over time. The paper synthesises organisational learning theory, benchmarking theory, mimetic isomorphism and institutional theories, which are presented as "the Red Queen", itself an evolutionary theory; this synthesis provides the theoretical underpinning. The Red Queen theory posits that competition triggers organisational learning, which in turn intensifies competition in rivals that ultimately triggers an adaptive response. This selfreinforcing process produces results that may be adaptive or maladaptive. There is evidence to support that “running fast” in terms of Red Queen evolution theory has allowed some universities to place competitive pressure on rivals and achieve elite levels of publications, international accreditation and improved international rankings. This search for improvement, driven by commercialisation, provided ways to improve performance, thus improving the university’s competitive strength. There is also evidence to support the belief that “running slow” provides maladaptive consequences that could affect growth rates, quality and staff performance. The use of the Red Queen hypothesis provides an evolutionary approach to the study of strategy, strategic change and organisations. This provides an opportunity to examine competition in universities as a force that continually disturbs equilibrium.

  4. Workers and alate queens of Solenopsis geminata share qualitatively similar but quantitatively different venom alkaloid chemistry

    Directory of Open Access Journals (Sweden)

    Qun-Hui eShi

    2015-07-01

    Full Text Available Solenopsis geminata group (Hymenoptera: Formicidae encompasses ant species commonly called fire ants because of their painful sting. The many physiological effects of the venom are caused by 2-methyl-6-alkyl and/or alkenylpiperidine alkaloids. The variation in piperidine alkaloid structures has useful taxonomic characters. The most well studied Solenopsis species is S. invicta, which was accidentally imported into the USA in the 1930s from South America. It quickly spread throughout the southern USA and is now a major invasive pest ant in the USA and in other parts of the world. Interestingly, the invasive S. invicta has largely displaced a native USA fire ant, S. geminata, from the southern USA. We explore the possibility that differences in venom chemistry could be correlated with this displacement. The cis and trans alkaloids from body extracts of workers and alate queens of S. geminata were separated by silica gel chromatography, identified, and quantitated by GC-MS analysis. Both workers and alate queens produce primarily cis- and trans-2-methyl-6-n-undecyl-piperidines, as well as other minor alkaloid components. Imported fire ant, S. invicta, alate queens produce the same alkaloids as S. geminata alate queens, but in contrast S. invicta workers produce piperidine alkaloids with longer side chains, which are purported to be physiologically more effective. These results are discussed in relation to the evolutionary progression of fire ant venom alkaloids and displacement of S. geminata by S. invicta in the USA.

  5. Does it Pay to do Well in Competitions? The case of the Queen Elizabeth Piano Competition

    NARCIS (Netherlands)

    Ginsburgh, V.; van Ours, J.C.

    2001-01-01

    Pianists who achieve high scores in the Queen Elizabeth musical competition are rewarded by subsequent success.It is not clear whether this is caused by the score itself or because those who have high scores are better pianists anyway. Since the timing and the order of appearance are good

  6. Worker laying in the absence of an ergatoid queen in the ponerine ...

    African Journals Online (AJOL)

    1987-06-12

    Jun 12, 1987 ... orphaned groups of workers were kept in the laboratory for several months, during which time many eggs were laid. Some of these developed into males. Thus workers can lay haploid eggs in the absence of an ergatoid queen. This was confirmed by dissecting 60 workers from various nests: many of them ...

  7. Worker laying in the absence of an ergatoid queen in the ponerine ...

    African Journals Online (AJOL)

    Ergatoid queens (without wings and worker-like) occur in Plectroctena mandibularis and P. conjugata. Five nests of these species were incompletely excavated, and an ergatoid was collected in only one of them. The orphaned groups of workers were kept in the laboratory for several months, during which time many eggs ...

  8. Honey bee queens do not count mates to assess their mating success

    Science.gov (United States)

    The mating system of honey bees (genus Apis) is extremely polyandrous, where reproductive females (queens) typically mate with 12 or more males (drones) during their mating flight(s). The evolutionary implications for hyperpolyandry have been subject to considerable debate and empirical testing beca...

  9. Co-occurrence of mated workers and a mated queen in a colony of ...

    African Journals Online (AJOL)

    arnoldi (Hymenoptera: Formicidae). Martin Villet *. Department of Zoology, University of the Witwatersrand, P.O.. Wits, 2050 Republic of South Africa. Received 23 March 1992; accepted 8 June 1992. A colony of Platythyrea arnold; was found to contain a functional queen and laying workers, both virgin and mated. This form ...

  10. Simplified Analytical Model for a Queen-Post Covered Timber Bridge

    Science.gov (United States)

    F Fanous; D. Rammer; T. Wipf

    2013-01-01

    During the 19th century, the economic material to build bridges was timber due to its abundant availability, cost, and ease of construction. Many of the well-known timber bridge types are the Burr arch, Town lattice, Howe, Queen and King type of trusses. This paper summarizes an investigation that was sponsored by the Federal Highway Administration and the USDA Forest...

  11. Identifying the Transition between Single and Multiple Mating of Queens in Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R.

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  12. Sequential generations of honey bee (Apis mellifera) queens produced using cryopreserved semen.

    Science.gov (United States)

    Hopkins, Brandon K; Herr, Charles; Sheppard, Walter S

    2012-01-01

    Much of the world's food production is dependent on honey bees for pollination, and expanding food production will further increase the demand for managed pollination services. Apiculturists outside the native range of the honey bee, in the Americas, Australia and eastern Asia, have used only a few of the 27 described subspecies of honey bees (Apis mellifera) for beekeeping purposes. Within the endemic ranges of a particular subspecies, hybridisation can threaten native subspecies when local beekeepers import and propagate non-native honey bees. For many threatened species, cryopreserved germplasm can provide a resource for the preservation of diversity and recovery of endangered populations. However, although instrumental insemination of queen honey bees is well established, the absence of an effective means to cryopreserve honey bee semen has limited the success of efforts to preserve genetic diversity within the species or to develop repositories of honey bee germplasm for breeding purposes. Herein we report that some queens inseminated with cryopreserved semen were capable of producing a substantial number of fertilised offspring. These diploid female larvae were used to produce two additional sequential generations of new queens, which were then back-crossed to the same stock of frozen semen. Our results demonstrate the ability to produce queens using cryopreserved honey bee spermatozoa and the potential for the establishment of a honey bee genetic repository.

  13. Outrunning the Red Queen: bystander activation as a means of outpacing innate immune subversion by intracellular pathogens.

    Science.gov (United States)

    Holmgren, Alicia M; McConkey, Cameron A; Shin, Sunny

    2017-01-01

    Originally described by the late evolutionary biologist Leigh Van Valen, the Red Queen hypothesis posits that the evolutionary arms race between hosts and their pathogens selects for discrete, genetically encoded events that lead to competitive advantages over the other species. Examples of immune evasion strategies are seen throughout the co-evolution of the mammalian immune system and pathogens, such as the enzymatic inactivation of nuclear factor-κB signaling or host translation by pathogen-encoded virulence factors. Such immunoevasive maneuvers would be expected to select for the evolution of innate immune counterstrategies. Recent advances in our understanding of host immunity and microbial pathogenesis have provided insight into a particular innate immune adaptation, termed bystander activation. Bystander activation occurs as a consequence of infected cells alerting and instructing neighboring uninfected cells to produce inflammatory mediators, either through direct cell contact or paracrine signals. Thus, bystander activation can allow the immune system to overcome the ability of pathogens to disarm immune signaling in directly infected cells. This review presents an overview of the general hallmarks of bystander activation and their emerging role in innate immunity to intracellular pathogens, as well as examples of recent mechanistic discoveries relating to the bystander activation during infection with specific pathogens relevant to human health and disease.

  14. Genomic analysis of post-mating changes in the honey bee queen (Apis mellifera

    Directory of Open Access Journals (Sweden)

    Richard Freddie-Jeanne

    2008-05-01

    Full Text Available Abstract Background The molecular mechanisms underlying the post-mating behavioral and physiological transitions undergone by females have not been explored in great detail. Honey bees represent an excellent model system in which to address these questions because they exhibit a range of "mating states," with two extremes (virgins and egg-laying, mated queens that differ dramatically in their behavior, pheromone profiles, and physiology. We used an incompletely-mated mating-state to understand the molecular processes that underlie the transition from a virgin to a mated, egg-laying queen. We used same-aged virgins, queens that mated once but did not initiate egg-laying, and queens that mated once and initiated egg-laying. Results Differences in the behavior and physiology among groups correlated with the underlying variance observed in the top 50 predictive genes in the brains and the ovaries. These changes were correlated with either a behaviorally-associated pattern or a physiologically-associated pattern. Overall, these results suggest that the brains and the ovaries of queens are uncoupled or follow different timescales; the initiation of mating triggers immediate changes in the ovaries, while changes in the brain may require additional stimuli or take a longer time to complete. Comparison of our results to previous studies of post-mating changes in Drosophila melanogaster identified common biological processes affected by mating, including stress response and alternative-splicing pathways. Comparison with microarray data sets related to worker behavior revealed no obvious correlation between genes regulated by mating and genes regulated by behavior/physiology in workers. Conclusion Studying the underlying molecular mechanisms of post-mating changes in honey bee queens will not only give us insight into how molecular mechanisms regulate physiological and behavioral changes, but they may also lead to important insights into the evolution of

  15. Enhanced photovoltaic performance of inverted pyramid-based nanostructured black-silicon solar cells passivated by an atomic-layer-deposited Al2O3 layer

    Science.gov (United States)

    Chen, Hong-Yan; Lu, Hong-Liang; Ren, Qing-Hua; Zhang, Yuan; Yang, Xiao-Feng; Ding, Shi-Jin; Zhang, David Wei

    2015-09-01

    Inverted pyramid-based nanostructured black-silicon (BS) solar cells with an Al2O3 passivation layer grown by atomic layer deposition (ALD) have been demonstrated. A multi-scale textured BS surface combining silicon nanowires (SiNWs) and inverted pyramids was obtained for the first time by lithography and metal catalyzed wet etching. The reflectance of the as-prepared BS surface was about 2% lower than that of the more commonly reported upright pyramid-based SiNW BS surface over the whole of the visible light spectrum, which led to a 1.7 mA cm-2 increase in short circuit current density. Moreover, the as-prepared solar cells were further passivated by an ALD-Al2O3 layer. The effect of annealing temperature on the photovoltaic performance of the solar cells was investigated. It was found that the values of all solar cell parameters including short circuit current, open circuit voltage, and fill factor exhibit a further increase under an optimized annealing temperature. Minority carrier lifetime measurements indicate that the enhanced cell performance is due to the improved passivation quality of the Al2O3 layer after thermal annealing treatments. By combining these two refinements, the optimized SiNW BS solar cells achieved a maximum conversion efficiency enhancement of 7.6% compared to the cells with an upright pyramid-based SiNWs surface and conventional SiNx passivation.

  16. The origin and evolution of queen and fertility signals in Corbiculate bees.

    Science.gov (United States)

    Caliari Oliveira, Ricardo; Oi, Cintia Akemi; do Nascimento, Mauricio Meirelles Castro; Vollet-Neto, Ayrton; Alves, Denise Araujo; Campos, Maria Claudia; Nascimento, Fabio; Wenseleers, Tom

    2015-11-16

    In social Hymenoptera (ants, bees and wasps), various chemical compounds present on the cuticle have been shown to act as fertility signals. In addition, specific queen-characteristic hydrocarbons have been implicated as sterility-inducing queen signals in ants, wasps and bumblebees. In Corbiculate bees, however, the chemical nature of queen-characteristic and fertility-linked compounds appears to be more diverse than in ants and wasps. Moreover, it remains unknown how queen signals evolved across this group and how they might have been co-opted from fertility signals in solitary ancestors. Here, we perform a phylogenetic analysis of fertility-linked compounds across 16 species of solitary and eusocial bee species, comprising both literature data as well as new primary data from a key solitary outgroup species, the oil-collecting bee Centris analis, and the highly eusocial stingless bee Scaptotrigona depilis. Our results demonstrate the presence of fertility-linked compounds belonging to 12 different chemical classes. In addition, we find that some classes of compounds (linear and branched alkanes, alkenes, esters and fatty acids) were already present as fertility-linked signals in the solitary ancestors of Corbiculate bees, while others appear to be specific to certain species. Overall, our results suggest that queen signals in Corbiculate bees are likely derived from ancestral fertility-linked compounds present in solitary bees that lacked reproductive castes. These original fertility-linked cues or signals could have been produced either as a by-product of ovarian activation or could have served other communicative purposes, such as in mate recognition or the regulation of egg-laying.

  17. Honeybee Venom Proteome Profile of Queens and Winter Bees as Determined by a Mass Spectrometric Approach

    Science.gov (United States)

    Danneels, Ellen L.; Van Vaerenbergh, Matthias; Debyser, Griet; Devreese, Bart; de Graaf, Dirk C.

    2015-01-01

    Venoms of invertebrates contain an enormous diversity of proteins, peptides, and other classes of substances. Insect venoms are characterized by a large interspecific variation resulting in extended lists of venom compounds. The venom composition of several hymenopterans also shows different intraspecific variation. For instance, venom from different honeybee castes, more specifically queens and workers, shows quantitative and qualitative variation, while the environment, like seasonal changes, also proves to be an important factor. The present study aimed at an in-depth analysis of the intraspecific variation in the honeybee venom proteome. In summer workers, the recent list of venom proteins resulted from merging combinatorial peptide ligand library sample pretreatment and targeted tandem mass spectrometry realized with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS/MS). Now, the same technique was used to determine the venom proteome of queens and winter bees, enabling us to compare it with that of summer bees. In total, 34 putative venom toxins were found, of which two were never described in honeybee venoms before. Venom from winter workers did not contain toxins that were not present in queens or summer workers, while winter worker venom lacked the allergen Api m 12, also known as vitellogenin. Venom from queen bees, on the other hand, was lacking six of the 34 venom toxins compared to worker bees, while it contained two new venom toxins, in particularly serine proteinase stubble and antithrombin-III. Although people are hardly stung by honeybees during winter or by queen bees, these newly identified toxins should be taken into account in the characterization of a putative allergic response against Apis mellifera stings. PMID:26529016

  18. Honeybee venom proteome profile of queens and winter bees as determined by a mass spectrometric approach.

    Science.gov (United States)

    Danneels, Ellen L; Van Vaerenbergh, Matthias; Debyser, Griet; Devreese, Bart; de Graaf, Dirk C

    2015-10-30

    Venoms of invertebrates contain an enormous diversity of proteins, peptides, and other classes of substances. Insect venoms are characterized by a large interspecific variation resulting in extended lists of venom compounds. The venom composition of several hymenopterans also shows different intraspecific variation. For instance, venom from different honeybee castes, more specifically queens and workers, shows quantitative and qualitative variation, while the environment, like seasonal changes, also proves to be an important factor. The present study aimed at an in-depth analysis of the intraspecific variation in the honeybee venom proteome. In summer workers, the recent list of venom proteins resulted from merging combinatorial peptide ligand library sample pretreatment and targeted tandem mass spectrometry realized with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS/MS). Now, the same technique was used to determine the venom proteome of queens and winter bees, enabling us to compare it with that of summer bees. In total, 34 putative venom toxins were found, of which two were never described in honeybee venoms before. Venom from winter workers did not contain toxins that were not present in queens or summer workers, while winter worker venom lacked the allergen Api m 12, also known as vitellogenin. Venom from queen bees, on the other hand, was lacking six of the 34 venom toxins compared to worker bees, while it contained two new venom toxins, in particularly serine proteinase stubble and antithrombin-III. Although people are hardly stung by honeybees during winter or by queen bees, these newly identified toxins should be taken into account in the characterization of a putative allergic response against Apis mellifera stings.

  19. Resistance to Varroa destructor (Mesostigmata: Varroidae) when mite-resistant queen honey bees (Hymenoptera: Apidae) were free-mated with unselected drones.

    Science.gov (United States)

    Harbo, J R; Harris, J W

    2001-12-01

    This study demonstrated (1) that honey bees, Apis mellifera L, can express a high level of resistance to Varroa destructor Anderson & Trueman when bees were selected for only one resistant trait (suppression of mite reproduction); and (2) that a significant level of mite-resistance was retained when these queens were free-mated with unselected drones. The test compared the growth of mite populations in colonies of bees that each received one of the following queens: (1) resistant--queens selected for suppression of mite reproduction and artificially inseminated in Baton Rouge with drones from similarly selected stocks; (2) resistant x control--resistant queens, as above, produced and free-mated to unselected drones by one of four commercial queen producers; and (3) control--commercial queens chosen by the same four queen producers and free-mated as above. All colonies started the test with approximately 0.9 kg of bees that were naturally infested with approximately 650 mites. Colonies with resistant x control queens ended the 115-d test period with significantly fewer mites than did colonies with control queens. This suggests that beekeepers can derive immediate benefit from mite-resistant queens that have been free-mated to unselected drones. Moreover, the production and distribution of these free-mated queens from many commercial sources may be an effective way to insert beneficial genes into our commercial population of honey bees without losing the genetic diversity and the useful beekeeping characteristics of this population.

  20. Polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via Wnt/β-catenin pathway

    International Nuclear Information System (INIS)

    Patel, Rachana; Ingle, Arvind; Maru, Girish B.

    2008-01-01

    Tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. However, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, are limited. Hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of PBP extract employing 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in Sprague-Dawley rats as experimental model. The present study suggests that PBPs, like other tea polyphenols, also inhibit DMH-induced colorectal tumorigenesis by decreasing tumor volume and multiplicity. This study also shows that although the pretreatment with PBP extract could induce detoxifying enzymes in hepatic and colorectal tissue, it did not show any additional chemopreventive effects when compared to treatments with PBP extract after initiation with DMH. Mechanistically, PBP extract may inhibit colorectal carcinogenesis by decreasing DMH-induced cell proliferation via Wnt/β-catenin pathway. Treatments with PBP extract showed decreased levels of COX-2, c-MYC and cyclin D1 proteins which aid cell proliferation probably by regulating β-catenin by maintaining expression of APC and decreasing inactivation of GSK3β. DMH-induced activation of MAP kinases such as ERK and JNK was also found to be inhibited by treatments with PBP extract. In conclusion, the protective effects of PBP extract could be attributed to inhibition of DMH-induced cellular proliferation probably through β-catenin regulation

  1. Founding weaver ant queens (Oecophylla longinoda) increase production and nanitic worker size when adopting non-nestmate pupae

    DEFF Research Database (Denmark)

    Ouagoussounon, Issa; Offenberg, Joachim; Sinzogan, Antonio

    2015-01-01

    of offspring). Forty-five fertilized queens were divided into three treatments: 0 (control), 100 or 300 non-nestmate pupae transplanted to each colony. Pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high proportions of surviving (mean...... pupae. The size of hatching pupae produced by the resident queen also increased with the number of pupae transplanted, leading to larger nanitic workers in colonies adopting pupae. In conclusion, pupae transplantation may be used to produce larger colonies with larger worker ants and may thus reduce...

  2. Black-Dye-Based Dye-Sensitized Solar Cells using the Electrolyte Solutions Containing a Quaternary Phosphonium Iodide with a Various Alkyl Chain Length

    International Nuclear Information System (INIS)

    Ozawa, Hironobu; Urayama, Ayako; Arakawa, Hironori

    2016-01-01

    Solar cell performances of the cosensitized dye-sensitized solar cells (DSCs) with Black dye and D131 using the electrolyte solution containing a quaternary phosphonium iodide with a various alkyl chain length have been evaluated by the photoelectrochemical and the electrochemical impedance spectroscopic measurements. Effects of the difference of the central atom between the quaternary phosphonium iodide and the quaternary ammonium iodide on the solar cell performances have been clarified. The DSC using the electrolyte solution containing tetrabutylphosphonium iodide showed higher Jsc. value and lower Voc and FF values compared to those of the DSC using the electrolyte solution containing tetrabutylammonium iodide. In addition, effects of the alkyl chain length of the quaternary phosphonium iodide on the solar cell performances have been also investigated. The blocking effect of the quaternary phosphonium cation for the access of I 3 − to the TiO 2 surface was found to be improved with increasing the alkyl chain length. The highest conversion efficiency (11.3%) could be obtained in the cosensitized DSC with Black dye and D131 using the electrolyte solution containing a moderate concentration of tetraoctylphosphonium iodide under AM 1.5 (100 mW/cm 2 ) irradiation. This study demonstrated that the quaternary phosphonium iodide with a longer alkyl chain is also effective for the improvement of the conversion efficiency of the DSCs due to both the improvement of the electron lifetime in the TiO 2 photoelectrode and the slight increment of the conduction band energy of the TiO 2 .

  3. Black Willow

    Science.gov (United States)

    R. M. Krinard

    1980-01-01

    Black willow and other species of Salix together comprise a majority of the stocking. Cottonwood is the chief associate, particularly in the early stages, but green ash, sycamore, pecan, persimmon, waterlocust, American elm, baldcypress, red maple, sugarberry, box-elder, and in some areas, silver maple are invaders preceding the next successional stage.

  4. Counseling Blacks

    Science.gov (United States)

    Vontress, Clemmont E.

    1970-01-01

    Blacks have developed unique environmental perceptions, values, and attitudes, making it difficult for counselors to establish and maintain positive rapport. This article examines attitudinal ingredients posited by Carl Rogers for relevance to this problem, and suggests in-service training to help counselors and other professionals relate…

  5. Black Psyllium

    Science.gov (United States)

    ... by mouth for up to 6 weeks reduces blood sugar in people with type 2 diabetes. Cancer. Diarrhea. Irritable bowel syndrome (IBS). Other conditions. ... with the dose. Diabetes: Black psyllium can lower blood sugar levels ... with type 2 diabetes by slowing down absorption of carbohydrates. Monitor blood ...

  6. Sex allocation in fungus-growing ants: worker or queen control without symbiont-induced female bias

    DEFF Research Database (Denmark)

    Dijkstra, Michiel B.; Boomsma, Jacobus Jan

    2008-01-01

    The fungal cultivars of fungus-growing ants are vertically transmitted by queens but not males. Selection would therefore favor cultivars that bias the ants' sex ratio towards gynes, beyond the gyne bias that is optimal for workers and queens. We measured sex allocation in 190 colonies of six...... sympatric fungus-growing ant species. As predicted from relatedness, female bias was greater in four singly mated Sericomyrmex and Trachymyrmex species than in two multiply mated Acromyrmex species. Colonies tended to raise mainly a single sex, which could be partly explained by variation in queen number......, colony fecundity, and fungal garden volume for Acromyrmex and Sericomyrmex, but not for Trachymyrmex. Year of collection, worker number and mating frequency of Acromyrmex queens did not affect the colony sex ratios. We used a novel sensitivity analysis to compare the population sex allocation ratios...

  7. Multichannel Seismic Reflection Data - SCAR - Queen Maud Land - 1985-1986, SDLS CD-ROM vol 22

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1985-86 in the Queen Maud Land region, Antarctica, by the Japan National Oil...

  8. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.

    1979-01-01

    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  9. Quantum black holes

    CERN Document Server

    Calmet, Xavier; Winstanley, Elizabeth

    2014-01-01

    Written by foremost experts, this short book gives a clear description of the physics of quantum black holes. The reader will learn about quantum black holes in four and higher dimensions, primordial black holes, the production of black holes in high energy particle collisions, Hawking radiation, black holes in models of low scale quantum gravity and quantum gravitational aspects of black holes.

  10. In utero exposure to nanosized carbon black (Printex90) does not induce tandem repeat mutations in female murine germ cells

    DEFF Research Database (Denmark)

    Boisen, Anne Mette Zenner; Shipley, Thomas; Jackson, Petra

    2013-01-01

    J mice were exposed four times during gestation by intratracheal instillation of 67μg/animal of nanosized carbon black Printex90 or vehicle (gestation days 7, 10, 15 and 18). Female offspring were raised to maturity and mated with unexposed CBA males. Expanded simple tandem repeat (ESTR) germline...... mutation rates in the resulting F2 generation were determined from full pedigrees (mother, father, offspring) of F1 female mice (178 CB-exposed and 258 control F2 offspring). ESTR mutation rates in CB-exposed F2 female offspring were not statistically different from those of F2 female control offspring....

  11. Idiopathic brood disease syndrome and queen events as precursors of colony mortality in migratory beekeeping operations in the eastern United States.

    Science.gov (United States)

    vanEngelsdorp, Dennis; Tarpy, David R; Lengerich, Eugene J; Pettis, Jeffery S

    2013-02-01

    Using standard epidemiological methods, this study set out to quantify the risk associated with exposure to easily diagnosed factors on colony mortality and morbidity in three migratory beekeeping operations. Fifty-six percent of all colonies monitored during the 10-month period died. The relative risk (RR) that a colony would die over the short term (∼50 days) was appreciably increased in colonies diagnosed with Idiopathic Brood Disease Syndrome (IBDS), a condition where brood of different ages appear molten on the bottom of cells (RR=3.2), or with a "queen event" (e.g., evidence of queen replacement or failure; RR=3.1). We also found that several risk factors-including the incidence of a poor brood pattern, chalkbood (CB), deformed wing virus (DWV), sacbrood virus (SBV), and exceeding the threshold of 5 Varroa mites per 100 bees-were differentially expressed in different beekeeping operations. Further, we found that a diagnosis of several factors were significantly more or less likely to be associated with a simultaneous diagnosis of another risk factor. These finding support the growing consensus that the causes of colony mortality are multiple and interrelated. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Queen Christina’s esoteric interests as a background to her Platonic Academies

    Directory of Open Access Journals (Sweden)

    Susanna Åkerman

    2008-01-01

    Full Text Available In 1681 the blind quietist, Francois Malaval, stated that Queen Christina of Sweden late in life had ‘given up’ [Hermes] Trismegistos and the Platonists, in favour of the Church fathers. The statement does not explain what role the Church fathers were to play in her last years, but it does show that Christina really had been interested in the rather elitist and esoteric doctrine of Hermetic Platonic Christianity. In this article the author looks at her library to show the depth of this Hermetic involvement. Her interest serves as a background to her life as ex-queen in Italy after her famous abdication from the Swedish throne in 1654, when she was 27 years old.

  13. On the track of the Red Queen: bark beetles, their nematodes, local climate and geographic parthenogenesis.

    Science.gov (United States)

    Meirmans, S; Skorping, A; Løyning, M K; Kirkendall, L R

    2006-11-01

    Geographic parthenogenesis has been explained as resulting from parasite pressure (Red Queen hypothesis): several studies have found high degrees of sexuals where the prevalence of parasites is high. However, it is important to address whether prevalence of parasites mirrors risk of infection. We explored geographic parthenogenesis of Ips acuminatus bark beetles and their nematodes. Local climate is crucial for nematode stages outside the host, in spring and summer, and prevalence should thus be associated with those temperatures if prevalence reliably reflects exposure risk across populations. This was the case; however, high prevalence of a virulent nematode species was not associated with many sexuals, whereas highly sexual populations were characterized by high infection risk of benign nematodes. Low virulence of the latter makes Red Queen dynamics unlikely. Geographical patterns of parthenogenesis were instead associated with winter temperature and variance in temperature.

  14. Analysis for transient temperature distribution two phase flow using test section QUEEN-02

    International Nuclear Information System (INIS)

    Ainur Rosidi; Joko Prasetio; Edy Sumarno; Kiswanta; Heru Bambang

    2013-01-01

    Experiments on the transient temperature distribution using a two-phase flow test facility QUEEN-02 and BETA test loop was conducted. Purpose of the experiment is to study temperature distribution during the transient cooling process. Experiments performed with the variation of the initial temperature of hot rod test section QUEEN-02 of 350 °C and 500 °C as well as the flow of cooling water temperature is 90 °C with the direction of flow from the bottom up from the BETA test loop. The analysis shows that temperature have the same downward trend in its every point thermocouple for the same initial temperature during cooling. Initial temperature of 350 °C hot rods produced when temperatures drop to 90 °C (the same as the temperature of the cooling water) for 78 seconds while the initial temperature of 500 °C produces hot rod drop time 190 seconds. (author)

  15. The Macalister archive: records from the Queen's Hospital, Sidcup, 1917-1921.

    Science.gov (United States)

    Bamji, A N

    1993-04-01

    The Queen's Hospital opened in 1917 to care for soldiers receiving facial injuries in Western Front trenches, usually as a result of a gunshot wound. Some 8000 patients were treated by the medical teams of the UK, the Dominions and the USA. The wartime records were removed by their respective sections in 1921, but Queen Mary's Hospital has recently reacquired those of the New Zealand section, rescued from imminent destruction by Professor A.D. Macalister, late Dean of the Dental School at Dunedin, and kindly donated by him. There are 282 sets of case-notes containing typescript summaries, clinical photographs and radiographs, drawings, 77 watercolor paintings and a life-size wax model of head and upper torso illustrating some of the surgical techniques. The archive is a fine example of medical illustration 75 years ago, and provides invaluable detail on the plastic surgery and dental reconstructive methods that were developed at Sidcup.

  16. Effect of Irradiation on Queen Survivorship and Reproduction in the Invasive Fire Ant Solenopsis invicta (Hymenoptera: Formicidae) and a Proposed Phytosanitary Irradiation Treatment for Ants.

    Science.gov (United States)

    Follett, Peter A; Porcel, Sol; Calcaterra, Luis A

    2016-12-01

    We studied radiation tolerance in queens of the red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) to identify a dose that prevents reproduction. Virgin or fertile queens were collected from Santa Fe and Formosa provinces in Argentina and reared in the laboratory in microcolonies. Virgin queens were irradiated at 0 (control), 70, 90, 120, or 150 Gy, and fertile queens were irradiated at 0, 60, 125, and 190 Gy, and then followed for 11 wk in the microcolonies to evaluate survival and reproduction. Virgin queens lay trophic eggs that do not hatch, whereas fertile queens lay eggs that hatch and develop into brood. In general, queen oviposition and survival decreased with increasing irradiation dose. For virgin queens, no eggs were laid by irradiated queens after the third week, whereas the control queens continued laying eggs throughout the 11-wk experiment. For fertile queens, only one larva and no pupae was observed in the 60 Gy treatment and no larvae or pupae were observed in the 125 and 190 Gy treatments, whereas a total of 431 larvae and 83 pupae were produced by untreated control queens during 11 wks. Survivorship of virgin and fertile queens was similarly reduced by irradiation treatment. These results with S. invicta are consistent with previous findings for three other invasive ants, Wasmannia auropunctata (Roger), Pheidole megacephala (F.), and Linephithema humile (Mayr), that are hitchhiker pests on fresh horticultural commodities. A radiation dose of 150 Gy is proposed as a phytosanitary treatment to prevent reproduction in ants. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  17. Lactobacillus vespulae sp. nov., isolated from gut of a queen wasp (Vespula vulgaris).

    Science.gov (United States)

    Hoang, Van-An; Kim, Yeon-Ju; Nguyen, Ngoc-Lan; Kim, Si-Kwan; Yang, Deok-Chun

    2015-10-01

    A Gram-stain-positive, oxidase- and catalase-negative, rod-shaped, facultatively anaerobic bacterial strain, DCY75T, was isolated from a queen wasp (Vespula vulgaris). Growth occurred at 4–37 °C (optimum, 30 °C), at pH 3.5–8.0 (optimum, pH 5.0–6.0) and with ≤ 7.0 % (w/v) NaCl. Strain DCY75T produced gas during growth on glucose. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain DCY75T belonged to the genus Lactobacillus and was closely related to Lactobacillus sanfranciscensis ATCC 27651T and Lactobacillus lindneri DSM 20690T at sequence similarities of 96.7 and 96.4 %, respectively. A comparison of two housekeeping genes, pheS and rpoA, revealed that strain DCT75T was well separated from other species of the genus Lactobacillus. Strain DCY75T produced d- and l-lactic acid isomers in a ratio of 22.5 : 77.5 (v/v). The major fatty acids were summed feature 8 (comprising C18 :  1ω7c and/or C18 : 1ω6c), C16 : 0, C18 : 1ω9c and C18 : 0.The peptidoglycan structure was of the A4α (l-Lys–d-Asp) type. Cell-wall sugars were glucose, galactose and ribose. The DNA G+C content was 35.5 ± 1.3 mol%. Based on phenotypic and genotypic properties, strain DCY75T represents a novel species of the genus Lactobacillus, for which the name Lactobacillus vespulae sp. nov. is proposed. The type strain is DCY75T ( = KCTC 21023T = JCM 19742T).

  18. A queen pheromone induces workers to kill sexual larvae in colonies of the red imported fire ant (Solenopsis invicta).

    Science.gov (United States)

    Klobuchar, Emily A; Deslippe, Richard J

    2002-07-01

    We conducted five bioassays to study how queens control the execution of sexual larvae by workers in colonies of the red imported fire ant, Solenopsis invicta. In each assay, subset colonies were made from many large polygyne colonies, and the 20 sexual larvae they contained were monitored over time. Sexual larvae mostly survived in queenless colonies, but were mostly killed in colonies with a single dealated queen, regardless of whether or not the queen was fertilized. The larvae were also killed when fresh corpses of queens were added to queenless colonies. Whereas acetone extracts of queens did not produce a significant increase in killings, extracts in buffered saline induced workers to execute most sexual larvae, indicating successful extraction of an execution pheromone. We identified the probable storage location of the chemical as the poison sac, and found both fresh (1 day) and old (21 day) extracts of poison sacs to be equally effective in inducing executions. The pheromone is stable at room temperature, perhaps because venom alkaloids also present in the extracts keep the pheromone from degrading. It is apparently either proteinaceous or associated with a proteinaceous molecule, a novel finding, as no queen pheromone of a proteinaceous nature has been previously demonstrated in ants.

  19. Influence of toxic bait type and starvation on worker and queen mortality in laboratory colonies of Argentine ant (Hymenoptera: Formicidae).

    Science.gov (United States)

    Mathieson, Melissa; Toft, Richard; Lester, Philip J

    2012-08-01

    The efficacy of toxic baits should be judged by their ability to kill entire ant colonies, including the colony queen or queens. We studied the efficacy of four toxic baits to the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). These baits were Xstinguish that has the toxicant fipronil, Exterm-an-Ant that contains both boric acid and sodium borate, and Advion ant gel and Advion ant bait arena that both have indoxacarb. Experimental nests contained 300 workers and 10 queen ants that were starved for either 24 or 48 h before toxic bait exposure. The efficacy of the toxic baits was strongly influenced by starvation. In no treatment with 24-h starvation did we observe 100% worker death. After 24-h starvation three of the baits did not result in any queen deaths, with only Exterm-an-Ant producing an average of 25% mortality. In contrast, 100% queen and worker mortality was observed in colonies starved for 48 h and given Xstinguish or Exterm-an-Ant. The baits Advion ant gel and Advion ant bait arena were not effective against Argentine ants in these trials, resulting in ants are likely to be starved. Our results suggest queen mortality must be assessed in tests for toxic bait efficacy. Our data indicate that of these four baits, Xstinguish and Exterm-an-Ant are the best options for control of Argentine ants in New Zealand.

  20. Community-led cancer action councils in Queens, New York: process evaluation of an innovative partnership with the Queens library system.

    Science.gov (United States)

    Basu Roy, Upal; Michel, Tamara; Carpenter, Alison; Lounsbury, David W; Sabino, Eilleen; Stevenson, Alexis Jurow; Combs, Sarah; Jacobs, Jasmine; Padgett, Deborah; Rapkin, Bruce D

    2014-02-06

    Community-based participatory research (CBPR) has great potential to address cancer disparities, particularly in racially and ethnically diverse and underserved neighborhoods. The objective of this study was to conduct a process evaluation of an innovative academic-community partnership, Queens Library HealthLink, which aimed to reduce cancer disparities through neighborhood groups (Cancer Action Councils) that convened in public libraries in Queens, New York. We used a mixed-methods approach to conduct 69 telephone survey interviews and 4 focus groups (15 participants) with Cancer Action Council members. We used 4 performance criteria to inform data collection: action or attention to sustainability, library support for the council, social cohesion and group leadership, and activity level. Focus group transcripts were independently coded and cross-checked for consensus until saturation was achieved. Members reported benefits and barriers to participation. Thirty-three original focus group transcript codes were organized into 8 main themes related to member experiences: 1) library as a needed resource, 2) library as a reputable and nondenominational institution, 3) value of library staff, 4) need for a HealthLink specialist, 5) generation of ideas and coordination of tasks, 6) participation challenges, 7) use of community connections, and 8) collaboration for sustainability. In response to the process evaluation, Cancer Action Council members and HealthLink staff incorporated member suggestions to improve council sustainability. The councils merged to increase intercouncil collaboration, and institutional changes were made in funding to sustain a HealthLink specialist beyond the grant period.

  1. Anti-metastasis activity of black rice anthocyanins against breast cancer: analyses using an ErbB2 positive breast cancer cell line and tumoral xenograft model.

    Science.gov (United States)

    Luo, Li-Ping; Han, Bin; Yu, Xiao-Ping; Chen, Xiang-Yan; Zhou, Jie; Chen, Wei; Zhu, Yan-Feng; Peng, Xiao-Li; Zou, Qiang; Li, Sui-Yan

    2014-01-01

    Increasing evidence from animal, epidemiological and clinical investigations suggest that dietary anthocyanins have potential to prevent chronic diseases, including cancers. It is also noteworthy that human epidermal growth factor receptor 2 (ErbB2) protein overexpression or ErbB2 gene amplification has been included as an indicator for metastasis and higher risk of recurrence for breast cancer. The present experiments investigated the anti-metastasis effects of black rice anthocyanins (BRACs) on ErbB2 positive breast cancer cells in vivo and in vitro. Oral administration of BRACs (150 mg/kg/day) reduced transplanted tumor growth, inhibited pulmonary metastasis, and decreased lung tumor nodules in BALB/c nude mice bearing ErbB2 positive breast cancer cell MDA-MB-453 xenografts. The capacity for migration, adhesion, motility and invasion was also inhibited by BRACs in MDA-MB-453 cells in a concentration dependent manner, accompanied by decreased activity of a transfer promoting factor, urokinase-type plasminogen activator (u-PA). Together, our results indicated that BRACs possess anti-metastasis potential against ErbB2 positive human breast cancer cells in vivo and in vitro through inhibition of metastasis promoting molecules.

  2. Legal syringe purchases by injection drug users, Brooklyn and Queens, New York City, 2000-2001.

    Science.gov (United States)

    Des Jarlais, Don C; McKnight, Courtney; Friedmann, Patricia

    2002-01-01

    To assess preliminary results of the Expanded Syringe Access Demonstration Program (ESAP) in New York City. Temporal trends of pharmacy use among injection drug users (IDUs) in Brooklyn and Queens were analyzed from December 2000 through December 2001. Brooklyn and Queens, New York City. PARTIPANTS: IDUs. Attempts to purchase syringes from pharmacies and success in doing so. Of the 1,072 IDUs interviewed from December 2000 through December 2001, the majority were daily heroin injectors, but there was also substantial speedball and cocaine injection. There was a clear increase over time in both the percentage of subjects who attempted to purchase syringes in pharmacies and in the percentage who successfully purchased syringes. Among IDUs interviewed 4 or more months after ESAP began, large majorities of those who attempted to purchase syringes were successful in doing so. No differences in use of ESAP by IDUs were identified in Brooklyn versus Queens: 27% of IDUs interviewed in Queens reported that they had attempted to purchase syringes in pharmacies versus 28% in Brooklyn. Persons who reported injecting on a daily or more frequent basis were more likely to have attempted pharmacy purchases than persons who reported injecting less frequently, 32% versus 21%. The ESAP program has led to an increase in the use of pharmacies as sources of sterile injection equipment among IDUs in New York City. The extent to which pharmacies become an important source of sterile injection equipment and the effect of legal pharmacy sales on risk behaviors for human immunodeficiency virus (HIV) infection remain to be determined.

  3. An observation study on the effects of queen age on some characteristics of honey bee colonies

    Directory of Open Access Journals (Sweden)

    Ibrahim Çakmak

    2010-01-01

    Full Text Available This study was conducted to determine the effects of the queen’s age on performance of the honeybee (A. mellifera anatoliaca colonies at nomad beekeeping conditions. Performances of the colonies, which had 0, 1, 2 and 3 year-old queens, were compared. The number of combs, brood areas, wintering ability survival rate and honey yield were determined as performance criteria. The average number of combs with bees throughout the experiment in Group I, Group II, Group III and Group IV was 10.92±0.78, 14.68±0.55, 10.10±0.60, 7.88±0.45 number combs/colony; the average of brood areas was 3078±372.5 cm2, 3668±460.3 cm2, 2215±294.0 cm2, 1665.38±241.8 cm2; the average of wintering ability was 84.3±2.9%, 88.0±3.7%, 46.6±19.0%, 26.8±16.5%; the survival rate was 100%, 100%, 60%, 40%; and the average of honey yields was 31.4±1.89 kg, 41.5±1.05 kg, 20.4±2.62 kg and 12.0±1.41 kg per colony, respectively. A significant and negative correlation between queen age and brood production (r=-80.2, colony strength (r=-62.5, wintering ability (r=-66 and honey yield (r=-75.6 were calculated (P<0.01. The colonies headed by young queens had more brood areas, longer worker colony population, better wintering ability and greater honey yield in comparison to colonies headed by old queens.

  4. Impact of chronic neonicotinoid exposure on honeybee colony performance and queen supersedure.

    Directory of Open Access Journals (Sweden)

    Christoph Sandrock

    Full Text Available BACKGROUND: Honeybees provide economically and ecologically vital pollination services to crops and wild plants. During the last decade elevated colony losses have been documented in Europe and North America. Despite growing consensus on the involvement of multiple causal factors, the underlying interactions impacting on honeybee health and colony failure are not fully resolved. Parasites and pathogens are among the main candidates, but sublethal exposure to widespread agricultural pesticides may also affect bees. METHODOLOGY/PRINCIPAL FINDINGS: To investigate effects of sublethal dietary neonicotinoid exposure on honeybee colony performance, a fully crossed experimental design was implemented using 24 colonies, including sister-queens from two different strains, and experimental in-hive pollen feeding with or without environmentally relevant concentrations of thiamethoxam and clothianidin. Honeybee colonies chronically exposed to both neonicotinoids over two brood cycles exhibited decreased performance in the short-term resulting in declining numbers of adult bees (-28% and brood (-13%, as well as a reduction in honey production (-29% and pollen collections (-19%, but colonies recovered in the medium-term and overwintered successfully. However, significantly decelerated growth of neonicotinoid-exposed colonies during the following spring was associated with queen failure, revealing previously undocumented long-term impacts of neonicotinoids: queen supersedure was observed for 60% of the neonicotinoid-exposed colonies within a one year period, but not for control colonies. Linked to this, neonicotinoid exposure was significantly associated with a reduced propensity to swarm during the next spring. Both short-term and long-term effects of neonicotinoids on colony performance were significantly influenced by the honeybees' genetic background. CONCLUSIONS/SIGNIFICANCE: Sublethal neonicotinoid exposure did not provoke increased winter losses. Yet

  5. Intrinsic worker mortality depends on behavioral caste and the queens' presence in a social insect

    Science.gov (United States)

    Kohlmeier, Philip; Negroni, Matteo Antoine; Kever, Marion; Emmling, Stefanie; Stypa, Heike; Feldmeyer, Barbara; Foitzik, Susanne

    2017-04-01

    According to the classic life history theory, selection for longevity depends on age-dependant extrinsic mortality and fecundity. In social insects, the common life history trade-off between fecundity and longevity appears to be reversed, as the most fecund individual, the queen, often exceeds workers in lifespan several fold. But does fecundity directly affect intrinsic mortality also in social insect workers? And what is the effect of task on worker mortality? Here, we studied how social environment and behavioral caste affect intrinsic mortality of ant workers. We compared worker survival between queenless and queenright Temnothorax longispinosus nests and demonstrate that workers survive longer under the queens' absence. Temnothorax ant workers fight over reproduction when the queen is absent and dominant workers lay eggs. Worker fertility might therefore increase lifespan, possibly due to a positive physiological link between fecundity and longevity, or better care for fertile workers. In social insects, division of labor among workers is age-dependant with young workers caring for the brood and old ones going out to forage. We therefore expected nurses to survive longer than foragers, which is what we found. Surprisingly, inactive inside workers showed a lower survival than nurses but comparable to that of foragers. The reduced longevity of inactive workers could be due to them being older than the nurses, or due to a positive effect of activity on lifespan. Overall, our study points to behavioral caste-dependent intrinsic mortality rates and a positive association between fertility and longevity not only in queens but also in ant workers.

  6. A comparison of honeybee (Apis mellifera) queen, worker and drone larvae by RNA-Seq.

    Science.gov (United States)

    He, Xu-Jiang; Jiang, Wu-Jun; Zhou, Mi; Barron, Andrew B; Zeng, Zhi-Jiang

    2017-11-06

    Honeybees (Apis mellifera) have haplodiploid sex determination: males develop from unfertilized eggs and females develop from fertilized ones. The differences in larval food also determine the development of females. Here we compared the total somatic gene expression profiles of 2-day and 4-day-old drone, queen and worker larvae by RNA-Seq. The results from a co-expression network analysis on all expressed genes showed that 2-day-old drone and worker larvae were closer in gene expression profiles than 2-day-old queen larvae. This indicated that for young larvae (2-day-old) environmental factors such as larval diet have a greater effect on gene expression profiles than ploidy or sex determination. Drones had the most distinct gene expression profiles at the 4-day larval stage, suggesting that haploidy, or sex dramatically affects the gene expression of honeybee larvae. Drone larvae showed fewer differences in gene expression profiles at the 2-day and 4-day time points than the worker and queen larval comparisons (598 against 1190 and 1181), suggesting a different pattern of gene expression regulation during the larval development of haploid males compared to diploid females. This study indicates that early in development the queen caste has the most distinct gene expression profile, perhaps reflecting the very rapid growth and morphological specialization of this caste compared to workers and drones. Later in development the haploid male drones have the most distinct gene expression profile, perhaps reflecting the influence of ploidy or sex determination on gene expression. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  7. Asexual queen succession mediates an accelerated colony life cycle in the termite Silvestritermes minutus

    Czech Academy of Sciences Publication Activity Database

    Fougeyrollas, R.; Křivánek, Jan; Roy, V.; Dolejšová, Klára; Frechault, S.; Roisin, Y.; Hanus, Robert; Sillam-Dusses, D.

    2017-01-01

    Roč. 26, č. 12 (2017), s. 3295-3308 ISSN 0962-1083 R&D Projects: GA ČR(CZ) GA14-12774S Institutional support: RVO:61388963 Keywords : asexual queen succession * breeding system * life history * parthenogenesis * Silvestritermes minutus * termites Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 6.086, year: 2016

  8. Honey bee males and queens use glandular secretions to enhance sperm viability before and after storage

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Boomsma, Jacobus Jan; Baer, Boris

    2009-01-01

    on sperm survival. After sperm storage, the queens also provide sperm with secretions from spermathecal glands and we show that these secretions have a comparable positive effect on sperm viability. SDS gels show that the proteomic profiles of accessory gland secretion and spermathecal fluid secretion...... hardly overlap, which suggests that males and females use different proteins to enhance sperm viability during, respectively, ejaculation and final sperm storage....

  9. Volunteering as Red Queen mechanism for cooperation in public goods games

    DEFF Research Database (Denmark)

    Hauert, C.; De Monte, Silvia; Hofbauer, J.

    2002-01-01

    under very diverse assumptions on population structure and adaptation mechanisms, leading usually not to an equilibrium but to an unending cycle of adjustments (a Red Queen type of evolution). Thus, voluntary participation offers an escape hatch out of some social traps. Cooperation can subsist...... in sizable groups even if interactions are not repeated, defectors remain anonymous, players have no memory, and assortment is purely random....

  10. Techniques for the In Vitro Production of Queens in Stingless Bees (Apidae, Meliponini)

    OpenAIRE

    Baptistella, Ana Rita; Souza, Camila C. M.; Santana, Weyder Cristiano; Egea Soares, Ademilson Espencer

    2012-01-01

    Considering the ecological importance of stingless bees as caretakers and pollinators of a variety of native plants makes it necessary to improve techniques which increase of colonies' number in order to preserve these species and the biodiversity associated with them. Thus, our aim was to develop a methodology of in vitro production of stingless bee queens by offering a large quantity of food to the larvae. Our methodology consisted of determining the amount of larval food needed for the dev...

  11. The potential for arms race and Red Queen coevolution in a protist host-parasite system.

    Science.gov (United States)

    Råberg, Lars; Alacid, Elisabet; Garces, Esther; Figueroa, Rosa

    2014-12-01

    The dynamics and consequences of host-parasite coevolution depend on the nature of host genotype-by-parasite genotype interactions (G × G) for host and parasite fitness. G × G with crossing reaction norms can yield cyclic dynamics of allele frequencies ("Red Queen" dynamics) while G × G where the variance among host genotypes differs between parasite genotypes results in selective sweeps ("arms race" dynamics). Here, we investigate the relative potential for arms race and Red Queen coevolution in a protist host-parasite system, the dinoflagellate Alexandrium minutum and its parasite Parvilucifera sinerae. We challenged nine different clones of A. minutum with 10 clones of P. sinerae in a fully factorial design and measured infection success and host and parasite fitness. Each host genotype was successfully infected by four to ten of the parasite genotypes. There were strong G × Gs for infection success, as well as both host and parasite fitness. About three quarters of the G × G variance components for host and parasite fitness were due to crossing reaction norms. There were no general costs of resistance or infectivity. We conclude that there is high potential for Red Queen dynamics in this host-parasite system.

  12. On the causes of selection for recombination underlying the red queen hypothesis.

    Science.gov (United States)

    Salathé, Marcel; Kouyos, Roger D; Bonhoeffer, Sebastian

    2009-07-01

    The vast majority of plant and animal species reproduce sexually despite the costs associated with sexual reproduction. Genetic recombination might outweigh these costs if it helps the species escape parasite pressure by creating rare or novel genotypes, an idea known as the Red Queen hypothesis. Selection for recombination can be driven by short- and long-term effects, but the relative importance of these effects and their dependency on the parameters of an antagonistic species interaction remain unclear. We use computer simulations of a mathematical model of host-parasite coevolution to measure those effects under a wide range of parameters. We find that the real driving force underlying the Red Queen hypothesis is neither the immediate, next-generation, short-term effect nor the long-term effect but in fact a delayed short-term effect. Our results highlight the importance of differentiating clearly between immediate and delayed short-term effects when attempting to elucidate the mechanism underlying selection for recombination in the Red Queen hypothesis.

  13. Hill-Robertson interference maintained by Red Queen dynamics favours the evolution of sex.

    Science.gov (United States)

    da Silva, J; Galbraith, J D

    2017-05-01

    Although it is well established theoretically that selective interference among mutations (Hill-Robertson interference) favours meiotic recombination, genomewide mean rates of mutation and strengths of selection appear too low to support this as the mechanism favouring recombination in nature. A possible solution to this discrepancy between theory and observation is that selection is at least intermittently very strong due to the antagonistic coevolution between a host and its parasites. The Red Queen theory posits that such coevolution generates fitness epistasis among loci, which generates negative linkage disequilibrium among beneficial mutations, which in turn favours recombination. This theory has received only limited support. However, Red Queen dynamics without epistasis may provide the ecological conditions that maintain strong and frequent selective interference in finite populations that indirectly selects for recombination. This hypothesis is developed here through the simulation of Red Queen dynamics. This approach required the development of a method to calculate the exact frequencies of multilocus haplotypes after recombination. Simulations show that recombination is favoured by the moderately weak selection of many loci involved in the interaction between a host and its parasites, which results in substitution rates that are compatible with empirical estimates. The model also reproduces the previously reported rapid increase in the rate of outcrossing in Caenorhabditis elegans coevolving with a bacterial pathogen. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  14. The shift between the Red Queen and the Red King effects in mutualisms.

    Science.gov (United States)

    Gao, Lei; Li, Yao-Tang; Wang, Rui-Wu

    2015-02-04

    Interspecific mutualisms consist of partners trading services that yield common benefits to both species. Until now, understanding how the payoffs from mutualistic cooperation are allocated among the participants has been problematic. Two hypotheses have been proposed to resolve this problem. The Red Queen effect argues that faster-evolving species are favoured in co-evolutionary processes because they are able to obtain a larger share of benefits. Conversely, the Red King effect argues that the slower-evolving species gains a larger share of benefits. The model we propose shows that the allocations for a common benefit vary when the effect of a reward mechanism is included in the model. The outcome is a shift from the Red Queen effect to the Red King effect and vice versa. In addition, our model shows that either an asymmetry in payoff or an asymmetry in the number of cooperative partners causes a shift between the Red Queen effect and the Red King effect. Even in situations where the evolutionary rates are equal between the two species, asymmetries in rewards and in participant number lead to an uneven allocation of benefits among the partners.

  15. The Red Queen model of recombination hot-spot evolution: a theoretical investigation.

    Science.gov (United States)

    Latrille, Thibault; Duret, Laurent; Lartillot, Nicolas

    2017-12-19

    In humans and many other species, recombination events cluster in narrow and short-lived hot spots distributed across the genome, whose location is determined by the Zn-finger protein PRDM9. To explain these fast evolutionary dynamics, an intra-genomic Red Queen model has been proposed, based on the interplay between two antagonistic forces: biased gene conversion, mediated by double-strand breaks, resulting in hot-spot extinction, followed by positive selection favouring new PRDM9 alleles recognizing new sequence motifs. Thus far, however, this Red Queen model has not been formalized as a quantitative population-genetic model, fully accounting for the intricate interplay between biased gene conversion, mutation, selection, demography and genetic diversity at the PRDM9 locus. Here, we explore the population genetics of the Red Queen model of recombination. A Wright-Fisher simulator was implemented, allowing exploration of the behaviour of the model (mean equilibrium recombination rate, diversity at the PRDM9 locus or turnover rate) as a function of the parameters (effective population size, mutation and erosion rates). In a second step, analytical results based on self-consistent mean-field approximations were derived, reproducing the scaling relations observed in the simulations. Empirical fit of the model to current data from the mouse suggests both a high mutation rate at PRDM9 and strong biased gene conversion on its targets.This article is part of the themed issue 'Evolutionary causes and consequences of recombination rate variation in sexual organisms'. © 2017 The Authors.

  16. West Pearl Queen CO2 sequestration pilot test and modeling project 2006-2008.

    Energy Technology Data Exchange (ETDEWEB)

    Engler, Bruce Phillip; Cooper, Scott Patrick; Symons, Neill Phillip; Bartel, Lewis Clark; Byrer, Charles (National Energy Laboratory, Morgantown, WV); Elbring, Gregory Jay; McNemar, Andrea (National Energy Laboratory, Morgantown, WV); Aldridge, David Franklin; Lorenz, John Clay

    2008-08-01

    The West Pearl Queen is a depleted oil reservoir that has produced approximately 250,000 bbl of oil since 1984. Production had slowed prior to CO{sub 2} injection, but no previous secondary or tertiary recovery methods had been applied. The initial project involved reservoir characterization and field response to injection of CO{sub 2}; the field experiment consisted of injection, soak, and venting. For fifty days (December 20, 2002, to February 11, 2003) 2090 tons of CO{sub 2} were injected into the Shattuck Sandstone Member of the Queen Formation at the West Pearl Queen site. This technical report highlights the test results of the numerous research participants and technical areas from 2006-2008. This work included determination of lateral extents of the permeability units using outcrop observations, core results, and well logs. Pre- and post-injection 3D seismic data were acquired. To aid in interpreting seismic data, we performed numerical simulations of the effects of CO{sub 2} replacement of brine where the reservoir model was based upon correlation lengths established by the permeability studies. These numerical simulations are not intended to replicate field data, but to provide insight of the effects of CO{sub 2}.

  17. Quantum chemical study on the stability of honeybee queen pheromone against atmospheric factors.

    Science.gov (United States)

    Shi, Rongwei; Liu, Fanglin

    2016-06-01

    The managed honeybee, Apis mellifera, has been experienced a puzzling event, termed as colony collapse disorder (CCD), in which worker bees abruptly disappear from their hives. Potential factors include parasites, pesticides, malnutrition, and environmental stresses. However, so far, no definitive relationship has been established between specific causal factors and CCD events. Here we theoretically test whether atmospheric environment could disturb the chemical communication between the queen and their workers in a colony. A quantum chemistry method has been used to investigate for the stability of the component of A. mellifera queen mandibular pheromone (QMP), (E)-9-keto-2-decenoic acid (9-ODA), against atmospheric water and free radicals. The results show that 9-ODA is less likely to react with water due to the high barrier heights (~36.5 kcal · mol(-1)) and very low reaction rates. However, it can easily react with triplet oxygen and hydroxyl radicals because of low or negative energy barriers. Thus, the atmospheric free radicals may disturb the chemical communication between the queen and their daughters in a colony. Our pilot study provides new insight for the cause of CCD, which has been reported throughout the world.

  18. Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee ( Apis mellifera)

    Science.gov (United States)

    Shi, Yuan Yuan; Yan, Wei Yu; Huang, Zachary Y.; Wang, Zi Long; Wu, Xiao Bo; Zeng, Zhi Jiang

    2013-02-01

    The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation.

  19. Clinical and Epidemiological Evidence of the Red Queen Hypothesis in Pneumococcal Serotype Dynamics.

    Science.gov (United States)

    Stockmann, Chris; Ampofo, Krow; Pavia, Andrew T; Blaschke, Anne J; Mason, Edward O; Presson, Angela P; Forney, Larry J; Byington, Carrie L

    2016-09-01

    The Red Queen hypothesis is an evolutionary theory that describes the reciprocal coevolution of competing species. We sought to study whether introduction of the 7- and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13, respectively) altered pneumococcal serotype dynamics among children with invasive pneumococcal disease (IPD) as predicted by the Red Queen hypothesis. This study examined pneumococcal isolates (n = 641) obtained from children <18 years of age hospitalized with IPD from 1997 to 2014 in Utah. A review of the literature also identified several additional studies conducted in the United States and Europe that were used to test the external generalizability of our Utah findings. Simpson's index was used to quantify pneumococcal serotype diversity. In Utah, the introduction of PCV7 and PCV13 was associated with rapid increases in serotype diversity (P < .001). Serotypes rarely present before vaccine introduction emerged as common causes of IPD. Diversity then decreased (P < .001) as competition selected for the fittest serotypes and new evolutionary equilibriums were established. This pattern was also observed more broadly in the United States, the United Kingdom, Norway, and Spain. This vaccine-driven example of human/bacterial coevolution appears to confirm the Red Queen hypothesis, which reveals a limitation of serotype-specific vaccines and offers insights that may facilitate alternative strategies for the elimination of IPD. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  20. Thelytokous Parthenogenesis in Unmated Queen Honeybees (Apis mellifera capensis): Central Fusion and High Recombination Rates

    Science.gov (United States)

    Oldroyd, Benjamin P.; Allsopp, Michael H.; Gloag, Rosalyn S.; Lim, Julianne; Jordan, Lyndon A.; Beekman, Madeleine

    2008-01-01

    The subspecies of honeybee indigenous to the Cape region of South Africa, Apis mellifera capensis, is unique because a high proportion of unmated workers can lay eggs that develop into females via thelytokous parthenogenesis involving central fusion of meiotic products. This ability allows pseudoclonal lineages of workers to establish, which are presently widespread as reproductive parasites within the honeybee populations of South Africa. Successful long-term propagation of a parthenogen requires the maintenance of heterozygosity at the sex locus, which in honeybees must be heterozygous for the expression of female traits. Thus, in successful lineages of parasitic workers, recombination events are reduced by an order of magnitude relative to meiosis in queens of other honeybee subspecies. Here we show that in unmated A. m. capensis queens treated to induce oviposition, no such reduction in recombination occurs, indicating that thelytoky and reduced recombination are not controlled by the same gene. Our virgin queens were able to lay both arrhenotokous male-producing haploid eggs and thelytokous female-producing diploid eggs at the same time, with evidence that they have some voluntary control over which kind of egg was laid. If so, they are able to influence the kind of second-division meiosis that occurs in their eggs post partum. PMID:18716331

  1. Role of relative humidity in colony founding and queen survivorship in two carpenter ant species.

    Science.gov (United States)

    Mankowski, Mark E; Morrell, J J

    2011-06-01

    Conditions necessary for optimal colony foundation in two carpenter ant species, Camponotus modoc Wheeler and Camponotus vicinus Mayr, were studied. Camponotus modoc and C. vicinus queens were placed in Douglas-fir, Pseudotsuga menziesii (Mirb. Franco) and Styrofoam blocks conditioned in sealed chambers at 70, 80, or 100% RH. Nanitic workers produced after 12 wk were used to assess the effects of substrate and moisture content on colony initiation. Queens of C. vicinus in Douglas-fir and Styrofoam produced worker numbers that did not differ significantly with moisture content; however, the number of colonies initiated by C. modoc differed significantly with moisture content. The results indicate that colony founding in C. vicinus is less sensitive to moisture content than C. modoc for Douglas-fir and Styrofoam. In another test, groups of queens of each species were exposed to 20, 50, 70, and 100% RH and the time until 50% mortality occurred was recorded for each species. C. vicinus lived significantly longer at each of the test humidities than C. modoc, suggesting that the former species is adapted to better survive under xeric conditions.

  2. Genotoxic effects of three selected black toner powders and their dimethyl sulfoxide extracts in cultured human epithelial A549 lung cells in vitro.

    Science.gov (United States)

    Gminski, Richard; Decker, Katharina; Heinz, Christina; Seidel, Albrecht; Könczöl, Mathias; Goldenberg, Ella; Grobéty, Bernard; Ebner, Winfried; Gieré, Reto; Mersch-Sundermann, Volker

    2011-05-01

    Until now, the adverse effects of toner powders on humans have been considered to be minimal. However, several recent reports have suggested possible significant adverse health effects from toner dust inhalation. The aim of this study was to evaluate the genotoxic potential of black toner powders in vitro. For the study of DNA damage, A549 cells were exposed to toner-powder suspensions and to their DMSO extracts, and then subjected to the comet assay and to the in-vitro cytokinesis block micronucleus test (CB-MNvit). Cytotoxic effects of the toner samples were assessed by the erythrosin B assay. Furthermore, size, shape, and composition of the toner powders were investigated. None of the three toner powders or their DMSO extracts reduced cell viability; however, they did induce DNA damage and formed micronuclei at concentrations from 80 to 400 μg cm(-2) , although to a varying extent. All toner powders contain considerable amounts of the pigments carbon black and magnetite (Fe(3) O(4) ) as well as small amounts of polycyclic aromatic hydrocarbons (PAHs). The overall results of our in-vitro study suggest that the investigated toner-powder samples are not cytotoxic but genotoxic. From the results of the physical and chemical characterization, we conclude that metals and metalloids as components of magnetite, or PAHs as components of the carbon-bearing material, are responsible for the genotoxic effects. Further research is necessary to determine the relevance of these in-vitro observations for private and occupational toner powder exposure. Copyright © 2010 Wiley-Liss, Inc.

  3. Assessing the Cytotoxicity of Black Carbon As A Model for Ultrafine Anthropogenic Aerosol Across Human and Murine Cells: A Chronic Exposure Model of Nanosized Particulate Matter

    Science.gov (United States)

    Salinas, E.

    2015-12-01

    Combustion-derived nanomaterials or ultrafine (population density, meteorological conditions, and industrial productivity brings high levels of air pollution to the metropolitan area of El Paso, Texas, USA/ Ciudad Juarez, Chihuahua, Mexico, comprising the Paso del Norte air basin. A study conducted by scientists from the Research Triangle Park in North Carolina, analyzed sites adjacent to heavy-traffic highways in El Paso and elucidated higher UFP concentrations in comparison to previously published work exploring pollution and adverse health effects in the basin. UFPs can penetrate deep into the alveolar sacs of the lung, reaching distant alveolar sacs and inducing a series of immune responses that are detrimental to the body: evidence suggests that UFPs can also cross the alveolar-blood barrier and potentially endanger the body's immune response. The physical properties of UFPs and the dynamics of local atmospheric and topographical conditions indicate that emissions of nanosized carbonaceous aerosols could pose significant threats to biological tissues upon inhalation by local residents of the Paso del Norte. This study utilizes Black Carbon (BC) as a model for environmental UFPs and its effects on the immunological response. An in vitro approach is used to measure the ability of BC to promote cell death upon long-term exposure. Human epithelial lung cells (A549), human peripheral-blood monocytes (THP-1), murine macrophages (RAW264.7), and murine epithelial lung cells (LA-4) were treated with BC and assessed for metabolic activity after chronic exposure utilizing three distinct and independent cell viability assays. The cell viability experiments included a chronic study at 7, 10, and 14 days of UFP exposure at six different concentrations of BC: 100μM, 300μM, 600μM, 1,250μM, 2,500μM, and 5,000μM conducting the Trypan Blue (TB) Exclusion Assay, Calcein-AM Viability Assay, and CellTiter-Glo Viability Assay.

  4. Design of Polymer-Coated Multi-Walled Carbon Nanotube/Carbon Black-based Fuel Cell Catalysts with High Durability and Performance Under Non-humidified Condition

    International Nuclear Information System (INIS)

    Yang, Zehui; Berber, Mohamed R.; Nakashima, Naotoshi

    2015-01-01

    To realize a high catalyst utilization, better fuel cell performance and durability as well as low production cost, an efficient design strategy of the catalyst layer that can improve both the oxygen accessibility and structure stability is highly required. Here, we describe the preparation of fuel cell electrocatalysts with an efficient fuel cell performance and better stability based on hybrids of multi-walled carbon nanotubes (MWNTs) and carbon black (CB) which were wrapped by a proton conducting polymer, poly[2,2′-(2,6-pyridine)-5,5′-bibenzimidazole], before deposition of the platinum (Pt) metal catalyst. The catalyst mass activity after feeding only 10%-MWNTs to CB increased by 1.5 and 2 times than those of the MWNTs-based- and CB-based catalysts, respectively. The results also demonstrated that 90 wt% of the MWNTs in the catalyst layer allows it to be replaced by CB without any significant change in its durability and performance under 120 °C and non-humidified condition

  5. Lack of induction of epithelial cell proliferation by sodium saccharin and sodium L-ascorbate in the urinary bladder of NCI-black-Reiter (NBR) male rats.

    Science.gov (United States)

    Uwagawa, S; Saito, K; Okuno, Y; Kawasaki, H; Yoshitake, A; Yamada, H; Fukushima, S

    1994-08-01

    The susceptibility to induction of epithelial cell proliferation by three urinary bladder cancer promoters was investigated in NCI-Black-Reiter (NBR) rats, which lack alpha 2u-globulin-synthesizing ability. Six-week-old male NBR and F344 rats were given 5% sodium saccharin (Na-Sac), 5% sodium L-ascorbate (Na-AsA), or 3% uracil in the basal diet for 8 weeks. Administration of uracil evoked a marked cell proliferation response and papillomatosis associated with calculus formation in NBR as well as F344 rats. This result indicates that NBR rats are also susceptible to direct mechanical stimulation. In contrast, both strains of rats given Na-Sac or Na-AsA demonstrated an alkalization of urinary pH and an increase in urinary Na ion concentration, but increase in cell proliferation in the urinary bladder transitional epithelium was only observed in F344 rats. Since previous studies revealed that elevation of urinary pH and Na ion concentration are essential factors for exertion of promotion activity by Na-Sac and Na-AsA, the results of the present investigation suggest that alpha 2u-globulin might also be a necessary component of the mechanisms of their promotion of male rat urinary bladder carcinogenesis.

  6. Immunolocalization of the short neuropeptide F receptor in queen brains and ovaries of the red imported fire ant (Solenopsis invicta Buren).

    Science.gov (United States)

    Lu, Hsiao-Ling; Pietrantonio, Patricia V

    2011-06-14

    Insect neuropeptides are involved in diverse physiological functions and can be released as neurotransmitters or neuromodulators acting within the central nervous system, and as circulating neurohormones in insect hemolymph. The insect short neuropeptide F (sNPF) peptides, related to the vertebrate neuropeptide Y (NPY) peptides, have been implicated in the regulation of food intake and body size, and play a gonadotropic role in the ovaries of some insect species. Recently the sNPF peptides were localized in the brain of larval and adult Drosophila. However, the location of the sNPF receptor, a G protein-coupled receptor (GPCR), has not yet been investigated in brains of any adult insect. To elucidate the sites of action of the sNPF peptide(s), the sNPF receptor tissue expression and cellular localization were analyzed in queens of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera), an invasive social insect. In the queen brains and subesophageal ganglion about 164 cells distributed in distinctive cell clusters (C1-C9 and C12) or as individual cells (C10, C11) were immuno-positive for the sNPF receptor. Most of these neurons are located in or near important sensory neuropils including the mushroom bodies, the antennal lobes, the central complex, and in different parts of the protocerebrum, as well as in the subesophageal ganglion. The localization of the sNPF receptor broadly links the receptor signaling pathway with circuits regulating learning and feeding behaviors. In ovaries from mated queens, the detection of sNPF receptor signal at the posterior end of oocytes in mid-oogenesis stage suggests that the sNPF signaling pathway may regulate processes at the oocyte pole. The analysis of sNPF receptor immunolocalization shows that the sNPF signaling cascade may be involved in diverse functions, and the sNPF peptide(s) may act in the brain as neurotransmitter(s) or neuromodulator(s), and in the ovaries as neurohormone(s). To our knowledge, this is the

  7. Immunolocalization of the short neuropeptide F receptor in queen brains and ovaries of the red imported fire ant (Solenopsis invicta Buren

    Directory of Open Access Journals (Sweden)

    Pietrantonio Patricia V

    2011-06-01

    Full Text Available Abstract Background Insect neuropeptides are involved in diverse physiological functions and can be released as neurotransmitters or neuromodulators acting within the central nervous system, and as circulating neurohormones in insect hemolymph. The insect short neuropeptide F (sNPF peptides, related to the vertebrate neuropeptide Y (NPY peptides, have been implicated in the regulation of food intake and body size, and play a gonadotropic role in the ovaries of some insect species. Recently the sNPF peptides were localized in the brain of larval and adult Drosophila. However, the location of the sNPF receptor, a G protein-coupled receptor (GPCR, has not yet been investigated in brains of any adult insect. To elucidate the sites of action of the sNPF peptide(s, the sNPF receptor tissue expression and cellular localization were analyzed in queens of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera, an invasive social insect. Results In the queen brains and subesophageal ganglion about 164 cells distributed in distinctive cell clusters (C1-C9 and C12 or as individual cells (C10, C11 were immuno-positive for the sNPF receptor. Most of these neurons are located in or near important sensory neuropils including the mushroom bodies, the antennal lobes, the central complex, and in different parts of the protocerebrum, as well as in the subesophageal ganglion. The localization of the sNPF receptor broadly links the receptor signaling pathway with circuits regulating learning and feeding behaviors. In ovaries from mated queens, the detection of sNPF receptor signal at the posterior end of oocytes in mid-oogenesis stage suggests that the sNPF signaling pathway may regulate processes at the oocyte pole. Conclusions The analysis of sNPF receptor immunolocalization shows that the sNPF signaling cascade may be involved in diverse functions, and the sNPF peptide(s may act in the brain as neurotransmitter(s or neuromodulator(s, and in the ovaries

  8. Uncoupling Flight and Reproduction in Ants: Evolution of Ergatoid Queens in Two Lineages of Megalomyrmex (Hymenoptera: Formicidae).

    Science.gov (United States)

    Peeters, Christian; Adams, Rachelle M M

    2016-01-01

    Megalomyrmex Forel (Myrmicinae: Solenopsidini) consists of 44 species with diverse life history strategies. Most species are predatory and may also tend honeydew-producing insects. A morphologically derived group of species are social parasites that consume the brood and fungus garden within fungus-growing ant nests. The reproductive strategies of Megalomyrmex queens are somewhat aligned with these life-style patterns. Predatory species in the leoninus species group are large in body size and have ergatoid (i.e., permanently wingless) queens whereas the social parasitic species are smaller and typically have winged queens. We examined two ergatoid phenotypes of Megalomyrmex foreli Emery and Megalomyrmex wallacei Mann and compared them to winged species, one a social lestobiotic or "thief ant" parasite (Megalomyrmex mondabora Brandão) and the other a predator (Megalomyrmex modestus Emery). Megalomyrmex foreli colonies have a single queen with an enlarged gaster that is morphologically distinct from workers. Megalomyrmex wallacei colonies have several queens that are similar in body size to workers. Queens in both species showed a simplification of the thorax, but there was a dramatic difference in the number of ovarioles. Megalomyrmex foreli had 60-80 ovarioles compared to eight in M. wallacei and M. mondabora and M. modestus had 22-28. Along with flight loss in queens, there is an obligate shift to dependent colony founding (also called budding or fission) consequently influencing dispersal patterns. These constraints in life history traits may help explain the variation in nesting biology among Megalomyrmex species. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

  9. 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.

  10. Effects of instrumental insemination and insemination quantity on Dufour's gland chemical profiles and vitellogenin expression in honey bee queens (Apis mellifera).

    Science.gov (United States)

    Richard, Freddie-Jeanne; Schal, Coby; Tarpy, David R; Grozinger, Christina M

    2011-09-01

    Honey bee queens (Apis mellifera) mate in their early adult lives with a variable number of males (drones). Mating stimulates dramatic changes in queen behavior, physiology, gene expression, and pheromone production. Here, we used virgin, single drone- (SDI), and multi-drone- (MDI) inseminated queens to study the effects of instrumental insemination and insemination quantity on the pheromone profiles of the Dufour's gland, and the expression of the egg-yolk protein, vitellogenin, in the fat body. Age, environmental conditions, and genetic background of the queens were standardized to specifically characterize the effects of these treatments. Our data demonstrate that insemination and insemination quantity significantly affect the chemical profiles of the Dufour's gland secretion. Moreover, workers were more attracted to Dufour's gland extract from inseminated queens compared to virgins, and to the extract of MDI queens compared to extract of SDI queens. However, while there were differences in the amounts of some esters between MDI queens and the other groups, it appears that the differences in behavioral responses were elicited by subtle changes in the overall chemical profiles rather than dramatic changes in specific individual chemicals. We also found a decrease in vitellogenin gene expression in the fat body of the MDI queens, which is negatively correlated with the quantities of Dufour's gland content. The possible explanations of this reduction are discussed.

  11. Black holes

    International Nuclear Information System (INIS)

    Carter, B.

    1980-01-01

    In years 1920 as a result of quantum mechanics principles governing the structure of ordinary matter, a sudden importance for a problem raised a long time ago by Laplace: what happens when a massive body becomes so dense that even light cannot escape from its gravitational field. It is difficult to conceive how could be avoided in the actual universe the accumulation of important masses of cold matter having been submitted to gravitational breaking down followed by the formation of what is called to day a black hole [fr

  12. Synthesis of Nanoporous TiO2 and Its Potential Applicability for Dye-Sensitized Solar Cell Using Antocyanine Black Rice

    Directory of Open Access Journals (Sweden)

    Brian Yuliarto

    2010-01-01

    Full Text Available Nanoporous mesostructure TiO2 powders were synthesized by sol-gel method, with TiCl4 as a precursor in methanol solution. The Pluronic PE 6200 of block copolymer was used as the pores template. It was found from XRD measurements, both at 400∘C and 450∘C calcination temperatures, that the sol-gel technique yielded the nanoporous TiO2 with anatase phase. Based on N2 adsorption characterization using BET method, the TiO2 samples have surface area of 108 m2/g and 88 m2/g for calcination temperatures of 400∘C and of 450∘C, respectively. From small-angle neutron scattering (SANS patterns, TiO2 samples were observed to have nanoporous structures with pore sizes between 22–24 nm. The TiO2 also have order degree which depends on the calcination temperature. The potential applicability of the resulting TiO2 is confirmed for dye-sensitized solar cell (DSSC, composed of nanoporous anatase TiO2 and natural dye from antocyanine black rice. UV-Vis measurement of dye extracted from the black rice indicated that the antocyanine chelate can propagate into the TiO2 nanoporous network. The short circuit photocurrent density (Jsc under 100 mWcm−2 reached 1.287 mAcm−2 with open circuit photovoltage (Voc of 550 mV and the fill factor of 33.4%. The results show that the hybrid organic-inorganic structures are very attractive for future low-cost devices.

  13. Radio protective effect of black mulberry extract on radiation-induced damage in bone marrow cells and liver in the rat

    Science.gov (United States)

    Ghasemnezhad Targhi, Reza; Homayoun, Mansour; Mansouri, Somaieh; Soukhtanloo, Mohammad; Soleymanifard, Shokouhozaman; Seghatoleslam, Masoumeh

    2017-01-01

    Ionizing radiation by producing free radicals induces tissue oxidative stress and has clastogenic and cytotoxic effects. The radio protective effect of black mulberry extract (BME) has been investigated on liver tissue and bone marrow cells in the rat. Intraperitoneal (ip) administration of 200 mg/kg BME three days before and three days after 3 Gy and 6 Gy gamma irradiation significantly reduced the frequencies of micro nucleated polychromatic erythrocytes (MnPCEs) and micro nucleated norm chromatic erythrocyte (MnNCEs) and increased PCE/PCE+NCE ratio in rat bone marrow compared to the non-treated irradiated groups. Moreover, this concentration of BME extract decreased the level of malondialdehyde (MDA) and superoxide dismutase (SOD), as well as enhanced the total thiol content and catalase activity in rat's liver compared to the non-treated irradiated groups. It seems that BME extract with antioxidant activity reduced the genotoxicity and cytotoxicity induced by gamma irradiation in bone marrow cells and liver in the rat.

  14. Sub-lethal effects of dietary neonicotinoid insecticide exposure on honey bee queen fecundity and colony development

    Science.gov (United States)

    Wu-Smart, Judy; Spivak, Marla

    2016-08-01

    Many factors can negatively affect honey bee (Apis mellifera L.) health including the pervasive use of systemic neonicotinoid insecticides. Through direct consumption of contaminated nectar and pollen from treated plants, neonicotinoids can affect foraging, learning, and memory in worker bees. Less well studied are the potential effects of neonicotinoids on queen bees, which may be exposed indirectly through trophallaxis, or food-sharing. To assess effects on queen productivity, small colonies of different sizes (1500, 3000, and 7000 bees) were fed imidacloprid (0, 10, 20, 50, and 100 ppb) in syrup for three weeks. We found adverse effects of imidacloprid on queens (egg-laying and locomotor activity), worker bees (foraging and hygienic activities), and colony development (brood production and pollen stores) in all treated colonies. Some effects were less evident as colony size increased, suggesting that larger colony populations may act as a buffer to pesticide exposure. This study is the first to show adverse effects of imidacloprid on queen bee fecundity and behavior and improves our understanding of how neonicotinoids may impair short-term colony functioning. These data indicate that risk-mitigation efforts should focus on reducing neonicotinoid exposure in the early spring when colonies are smallest and queens are most vulnerable to exposure.

  15. Males are here to stay: fertilization enhances viable egg production by clonal queens of the little fire ant ( Wasmannia auropunctata)

    Science.gov (United States)

    Miyakawa, Misato O.; Mikheyev, Alexander S.

    2015-04-01

    Evolution of reproduction strategies is affected by both phylogenetic and physiological constraints. Although clonality may benefit females, it may not be selected if a male contribution is necessary to start egg laying and embryo development. In little fire ant, Wasmannia auropunctata, sexual populations employ a typical Hymenopteran system of reproduction. In clonal populations, however, queens and males are produced with only maternal and paternal genomes, respectively, whereas sterile workers are produced sexually. Although this system requires both sexes for worker production, previous work has shown that workers may also be produced clonally by the queens. If so, why are males maintained in this species? Our data suggest that fertilization is necessary to increase the hatching rate of eggs. Although clonal queens can indeed produce both workers and queens without mating, the hatching rate is far below the level necessary to maintain functional colonies. On the other hand, virgin queens from populations exhibiting the original Hymenopteran reproduction system also show low hatching rates, but produce only haploid male eggs. Reasons for the existence of W. auropunctata males have been disputed. However, our data suggest that physiological constraints, such as the requirement for insemination, must be considered in regard to evolution of reproduction systems, in addition to ecological data and theoretical considerations of fitness.

  16. Review of samples of sediment, tailings, and waters adjacent to the Cactus Queen gold mine, Kern County, California

    Science.gov (United States)

    Rytuba, James J.; Kim, Christopher S.; Goldstein, Daniel N.

    2011-01-01

    The Cactus Queen Mine is located in the western Mojave Desert in Kern County, California. The Cactus Queen gold-silver (Au-Ag) deposit is similar to other Au-Ag deposits hosted in Miocene volcanic rocks that consist of silicic domes and associated flows, pyroclastic rocks, and subvolcanic intrusions. The volcanic rocks were emplaced onto a basement of Mesozoic silicic intrusive rocks. A part of the Cactus Queen Mine is located on Federal land managed by the U.S. Bureau of Land Management (BLM). Staff from the BLM initially sampled the mine area and documented elevated concentrations of arsenic (As) in tailings and sediment. BLM then requested that the U.S. Geological Survey (USGS), in collaboration with Chapman University, measure and characterize As and other geochemical constituents in sediment, tailings, and waters on the part of the mine on Federal lands. This report is made in response to the request by the BLM, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to the potential removal of As-contaminated mine waste from the Cactus Queen Mine as a means of reducing As release and exposure to humans and biota. This report summarizes data obtained from field sampling of sediments, mine tailings, and surface waters at the Cactus Queen Mine on January 27, 2008. Our results provide a preliminary assessment of the sources of As and associated chemical constituents that could potentially impact humans and biota.

  17. Making Blackness, Making Policy

    OpenAIRE

    Geller, Peter

    2012-01-01

    Too often the acknowledgment that race is a social construction ignores exactly how this construction occurs. By illuminating the way in which the category of blackness and black individuals are made, we can better see how race matters in America. Antidiscrimination policy, social science research, and the state's support of its citizens can all be improved by an accurate and concrete definition of blackness. Making Blackness, Making Policy argues that blackness and black people are literally...

  18. Assessment of Cellular Responses to Oxidative Stress using MCF-7 Breast Cancer Cells, Black Seed (N. Sativa L. Extracts and H2O2

    Directory of Open Access Journals (Sweden)

    Ibrahim O. Farah

    2005-12-01

    Full Text Available Black seed (N. Sativa L is an oriental spice of the family Ranunculaceae that has long been rationally used as a natural medicine for treatment of many acute as well as chronic conditions including cardiovascular disease and immunological disorders. It has been used in the treatment of diabetes, hypertension, and dermatological conditions. There have been very few studies on the effects of N. Sativa as a chemoprevention of chronic diseases as well as in cancer prevention and/or therapy. Oxidative stress is a condition that underlies many acute as well as chronic conditions. The combination and role of oxidative stress and antioxidants in vivo is still a matter of conjecture. Our objective for the present study was to expose MCF-7 breast cancer cells in vitro (as a chronic disease example to aqueous and alcohol extracts and in combination with H2O2 as an oxidative stressor. Measurement of cell survival under various concentrations and mixtures was conducted using standard cell culture techniques, exposure protocols in 96 well plates and Fluorospectrosphotometry. Following cellular growth to 90% confluencey, exposure to water (WE and ethanol (AE extracts of N. sativa and H2O2 was performed. Cell survival indices were calculated from percent survival using regression analysis. Results showed that the alcohol extract and its mixtures were able to influence the survival of MCF-7 cells (indices ranged from 357.15- 809.50 Bg/ml in descending potency for H2O2+AE to the mix of 3. In contrast, H2O2 alone reduced effectively the survival of MCF-7 cells and the least effective combinations in descending potency were AE+H2O2, WE+H2O2, AE+WE, and WE+AE+H2O2. Mixtures other than AE+H2O2 showed possible interactions and loss of potency. In conclusion, N. Sativa alone or in combination with oxidative stress was found to be effective (in vitro in influencing the survival of MCF-7 breast cancer cells, unveiling promising opportunities in the field of cancer

  19. The honey bee epigenomes: differential methylation of brain DNA in queens and workers.

    Directory of Open Access Journals (Sweden)

    Frank Lyko

    2010-11-01

    Full Text Available In honey bees (Apis mellifera the behaviorally and reproductively distinct queen and worker female castes derive from the same genome as a result of differential intake of royal jelly and are implemented in concert with DNA methylation. To determine if these very different diet-controlled phenotypes correlate with unique brain methylomes, we conducted a study to determine the methyl cytosine (mC distribution in the brains of queens and workers at single-base-pair resolution using shotgun bisulfite sequencing technology. The whole-genome sequencing was validated by deep 454 sequencing of selected amplicons representing eight methylated genes. We found that nearly all mCs are located in CpG dinucleotides in the exons of 5,854 genes showing greater sequence conservation than non-methylated genes. Over 550 genes show significant methylation differences between queens and workers, revealing the intricate dynamics of methylation patterns. The distinctiveness of the differentially methylated genes is underscored by their intermediate CpG densities relative to drastically CpG-depleted methylated genes and to CpG-richer non-methylated genes. We find a strong correlation between methylation patterns and splicing sites including those that have the potential to generate alternative exons. We validate our genome-wide analyses by a detailed examination of two transcript variants encoded by one of the differentially methylated genes. The link between methylation and splicing is further supported by the differential methylation of genes belonging to the histone gene family. We propose that modulation of alternative splicing is one mechanism by which DNA methylation could be linked to gene regulation in the honey bee. Our study describes a level of molecular diversity previously unknown in honey bees that might be important for generating phenotypic flexibility not only during development but also in the adult post-mitotic brain.

  20. Holocene Tree Line and Climate Change on the Queen Charlotte Islands, Canada

    Science.gov (United States)

    Pellatt, Marlow G.; Mathewes, Rolf W.

    1997-07-01

    Palynological study of two subalpine ponds on the Queen Charlotte Islands reveals changes in tree line and climate during the Holocene. The findings agree with previous reconstructions, from nearby Louise Pond on the Queen Charlotte Islands, that suggest a warmer-than-present climate and higher-than-present tree lines in the early Holocene (ca. 9600-6600 14C yr B.P.). Basal ages at SC1 Pond and Shangri-La Bog indicate that the basins did not hold permanent water before 7200 14C yr B.P., consistent with a warmer and drier early Holocene previously inferred from Louise Pond. Pollen and plant macrofossils indicate the initial establishment of subalpine conditions by 6090 ± 90 14C yr B.P., similar to the 5790 ± 130 14C yr B.P. age for cooling inferred from Louise Pond. Conditions similar to present were established at SC1 Pond by 3460 ± 100 14C yr B.P., confirming the previous estimate of 3400 14C yr B.P. at Louise Pond. This 3400 14C yr B.P. vegetation shift on the Queen Charlotte Islands corresponds with the beginning of the Tiedemann glacial advance in the south-coastal mountains of British Columbia (ca. 3300 14C yr B.P.), the Peyto and Robson glacial advances between 3300 and 2800 14C yr B.P. in the Rocky Mountains, and climatic cooling inferred from palynological studies throughout southern British Columbia, northern Washington, and southeast Alaska. These findings confirm that changes in regional climate influenced changes in vegetation in coastal British Columbia.

  1. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Black holes; numerical relativity; nonlinear sigma. Abstract. Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. ... Theoretical and Computational Studies Group, Southampton College, Long Island University, Southampton, NY 11968, USA ...

  2. The state of affairs in the kingdom of the Red Queen.

    Science.gov (United States)

    Salathé, Marcel; Kouyos, Roger D; Bonhoeffer, Sebastian

    2008-08-01

    One of the most prominent hypotheses to explain the ubiquity of sex and recombination is based on host-parasite interactions. Under the name of the Red Queen hypothesis (RQH), it has had theoretical and empirical support since its conception, but recent theoretical work has shown that the circumstances under which the RQH works remain unclear. Here we review the current status of the theory of the RQH. We argue that recent theoretical work calls for new experimental data and an increased theoretical effort to reveal the driving force of the RQH.

  3. Parasites in sexual and asexual mollies (Poecilia, Poeciliidae, Teleostei): a case for the Red Queen?

    Science.gov (United States)

    Tobler, Michael; Schlupp, Ingo

    2005-06-22

    The maintenance of sexual reproduction in the face of its supposed costs is a major paradox in evolutionary biology. The Red Queen hypothesis, which states that sex is an adaptation to fast-evolving parasites, is currently one of the most recognized explanations for the ubiquity of sex and predicts that asexual lineages should suffer from a higher parasite load if they coexist with closely related sexuals. We tested this prediction using four populations of the sexual fish species Poecilia latipinna and its asexual relative Poecilia formosa. Contrary to expectation, no differences in parasite load could be detected between the two species.

  4. Mary Queen of Scots as Feminine and National Icon: Depictions in Film and Fiction

    OpenAIRE

    Ágústsdóttir, Ingibjörg

    2013-01-01

    This article focuses on twentieth and twenty-first century depictions of Mary Queen of Scots in film and fiction. It examines the ways in which Mary’s story is presented and in what manner the myths surrounding her personality and actions are either upheld or deconstructed. While the article demonstrates that modern portrayals of Mary tend to follow the long tradition of seeing her as a version of femininity, Mary’s position as a symbol of the victimization of Scotland by England is also disc...

  5. A Genetic Algorithm Based Approach for Solving the Minimum Dominating Set of Queens Problem

    Directory of Open Access Journals (Sweden)

    Saad Alharbi

    2017-01-01

    Full Text Available In the field of computing, combinatorics, and related areas, researchers have formulated several techniques for the Minimum Dominating Set of Queens Problem (MDSQP pertaining to the typical chessboard based puzzles. However, literature shows that limited research has been carried out to solve the MDSQP using bioinspired algorithms. To fill this gap, this paper proposes a simple and effective solution based on genetic algorithms to solve this classical problem. We report results which demonstrate that near optimal solutions have been determined by the GA for different board sizes ranging from 8 × 8 to 11 × 11.

  6. Drag queens' use of language and the performance of blurred gendered and racial identities.

    Science.gov (United States)

    Mann, Stephen L

    2011-01-01

    Building on Barrett (1998), this study provides a sociolinguistic analysis of the language used by Suzanne, a European-American drag queen, during her on-stage performance in the southeastern United States. Suzanne uses wigs and costumes to portray a female character on stage, but never hides the fact that she is biologically male. She is also a member of a predominantly African-American cast. Through her creative use of linguistic features such as stylemixing (i.e., the use of linguistic features shared across multiple language varieties) and expletives, Suzanne is able to perform an identity that frequently blurs gender and racial lines.

  7. Distribution, diversity, mesonotal morphology, gallery architecture, and queen physogastry of the termite genus Calcaritermes (Isoptera, Kalotermitidae

    Directory of Open Access Journals (Sweden)

    Rudolf Scheffrahn

    2011-11-01

    Full Text Available An updated New World distribution of the genus Calcaritermes is given along with photographs and a key to the New World species outside Mexico. Calcaritermes recessifrons is found to be a junior synonym of C. nigriceps. Except for C. temnocephalus, pseudergates of the other seven studied Calcaritermes species possess a mesonotal rasp. The rasps suggest a role in propagation of microbes on gallery surfaces and microbial infusion below the wood surface. Calcaritermes temoncephalus is shown to have an unusually large physogastric queens for a kalotermitid and several species produce large eggs.

  8. Distribution, diversity, mesonotal morphology, gallery architecture, and queen physogastry of the termite genus Calcaritermes (Isoptera, Kalotermitidae).

    Science.gov (United States)

    Scheffrahn, Rudolf H

    2011-01-01

    An updated New World distribution of the genus Calcaritermes is given along with photographs and a key to the New World species outside Mexico. Calcaritermes recessifrons is found to be a junior synonym of Calcaritermes nigriceps. Except for Calcaritermes temnocephalus, pseudergates of the other seven studied Calcaritermes species possess a mesonotal rasp. The rasps suggest a role in propagation of microbes on gallery surfaces and microbial infusion below the wood surface. Calcaritermes temoncephalus is shown to have an unusually large physogastric queens for a kalotermitid and several species produce large eggs.

  9. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2016-06-01

    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  10. The effects of black garlic on the working memory and pyramidal cell number of medial prefrontal cortex of rats exposed to monosodium glutamate.

    Science.gov (United States)

    Nurmasitoh, Titis; Sari, Dwi Cahyani Ratna; Partadiredja, Ginus

    2017-12-27

    Monosodium glutamate-induced exitotoxicity causes oxidative stress in many brain areas, including the medial prefrontal cortex. The ethanolic garlic (Allium sativum) extract is considered as a neuroprotective substance. The present study aimed at investigating the effects of the ethanolic fermented garlic extract on the working memory and the pyramidal cell number of the medial prefrontal cortex of adolescent male Wistar rats exposed to monosodium glutamate (MSG). Twenty-five rats were randomly divided into five groups. The C- group was given 0.9% NaCl solution. The C + group was given 2 mg/g bw of MSG. The T1, T2, and T3 groups were given MSG and garlic extract (0.0125, 0.025, and 0.05 mg/g bw, respectively). All treatments were conducted for 10 days. The working memory capability of the rats was measured using Y-maze test. The total number of pyramidal cells of the medial prefrontal cortex was estimated using physical fractionator method. The working memory performances of the T1, T2, and T3 groups were significantly better than that of the C + group. There were no significant differences between groups in the estimated total number of pyramidal cell of medial prefrontal cortex. The MSG may not cause the death of neurons, but it may modify neuronal architectures that are sufficient to disrupt memory functions. Black garlic may play a role as an antioxidant agent that prevents the prefrontal cortex from glutamate-induced oxidative stress. It is concluded that the ethanolic fermented garlic extract prevented the working memory impairment following MSG administration.

  11. Preparation, characterization and evaluation of electrocatalysts supported on functionalized carbon black for polymer exchange membrane fuel cell applications; Preparacao, caracterizacao e avaliacao de eletrocatalisadores suportados em carbono funcionalizado para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Marcelo do

    2008-12-18

    The fuel cell technology associated with the growing exigency of low environmental impact energy became prosperous in the world energy scenery. The fuel cell is basically a device that converts directly the chemical energy of a fuel into electrical and thermal energy with a continuous operation by the constant feed of a fuel. Especially, the carbon black Vulcan XC72 is usually employed as an electro catalyst support, and some factors as an accessible and high surface area in order to get maximum particles dispersion, pore size, adequate pore distribution and the presence of functional groups in the carbon black surface are considered fundamental characteristics for an innovative materials development. However, the Vulcan XC72 still reveals insufficient conditions for these purposes. This study consists in the preparation and in the physical chemical characterization of functionalized carbon black by hydrogen peroxide and by polymeric chains with proton conduction properties, and its posterior utilization as electro catalyst support for PEMFC and DMFC application. After the carbon functionalization, an improvement in the carbon black dispersion in water media was observed, a beneficial effect for electro catalyst preparation. It was also observed, that the functional groups and the polymeric chains worked as stabilizers in the particle growing, producing much more homogeneous electrocatalysts, exhibiting smaller average particle size. Especially, in the case of polymeric chains functionalization, a decrease in the ohmic drop was observed for this system, attributed to an improvement in the proton transference. (author)

  12. Intra- and inter-observer variability in ultrasonographical measurements of the uterus and ovaries in healthy, non-pregnant queens.

    Science.gov (United States)

    Gatel, Laure; Gory, Guillaume; Chalvet-Monfray, Karine; Saunders, Jimmy H; Rault, Delphine N

    2016-02-01

    We aimed to (1) evaluate how frequently the uterus and ovaries of healthy, non-pregnant queens are visible; (2) describe their appearance; (3) take their measurements; and (4) determine intra- and inter-observer variabilities in their measurements. We hypothesised that, using a high-frequency linear probe, the uterus and ovaries could be ultrasonographically visualised during any period of the sexual cycle and with any level of operator expertise. Eight queens were enrolled in the study and the ultrasonographical appearance of their uterus and ovaries assessed with a high-frequency linear probe of 15-19 MHz. The diameter of the uterine horns, body and cervix in transverse and longitudinal sections, and the length of the ovaries were recorded. Three observers of different expertise level participated in the study, and the differences between the separate measurements made per queen were evaluated. The ovaries and the entire uterus were visualised in every queen. The ovaries were ovoid structures with submillimetric follicles during anoestrus and additional larger follicles depending on the stage of the cycle. An ovarian pattern suggesting cortex and medulla was observed in half the cases. In the uterus, the serosa was a thin hyperechoic outer rim, and layering was observed in half the cases. The cervix was difficult to identify. The intra- and inter-observer variabilities in the uterine horns and the ovaries were minimal (coefficient of variation [CV] 1.4-4.1%) compared with the differences within the queens (CV 10.9-43.4%). The longitudinal and transverse measurements of the horns and the uterine body were the same. The ovaries and uterine horns in queens are accessible ultrasonographically at any stage of their cycle, and can be measured with low intra- and inter-observer variabilities. © ISFM and AAFP 2015.

  13. Effects of an insect growth regulator and a solvent on honeybee (Apis mellifera L.) brood development and queen viability.

    Science.gov (United States)

    Milchreit, Kathrin; Ruhnke, Haike; Wegener, Jakob; Bienefeld, Kaspar

    2016-04-01

    Honeybee toxicology is complex because effects on individual bees are modulated by social interactions between colony members. In the present study, we applied high doses of the insect growth regulator fenoxycarb to honeybee colonies to elucidate a possible interplay of individually- and colony-mediated effects regarding honey bee toxicology. Additionally, possible effects of the solvent dimethyl sulfoxide (DMSO) were assessed. We conducted studies on egg hatching and brood development to assess brood care by nurse bees as well as queen viability. Egg hatching was determined by the eclosion rate of larvae from eggs originating from colonies (i) treated with sugar syrup only, (ii) treated with sugar syrup containing DMSO and (iii) treated with sugar syrup containing fenoxycarb (dissolved in DMSO). To evaluate brood development, combs with freshly laid eggs were reciprocally transferred between colonies, and development of brood was examined in the recipient hive. Brood reared inside DMSO- and fenoxycarb-treated colonies as well as brood from DMSO- and from fenoxycarb-exposed queens showed higher mortality than brood not exposed to the chemicals. No differences were found in egg hatching among the treatments, but there was a higher variability of eclosion rates after queens were exposed to fenoxycarb. We also observed queen loss and absconding of whole colonies. Based on our results we infer that fenoxycarb has queen- as well as nurse bee-mediated effects on brood quality and development which can lead to the queen's death. There also is an effect of DMSO on the nurse bees' performance that could disturb the colony's equilibrium, at least for a delimited timespan.

  14. Effect of irradiation on queen survivorship and reproduction in the invasive fire ant Solenopsis invicta,(Hymenoptera: Formicidae) and a generic phytosanitary irradiation treatment for ants

    Science.gov (United States)

    Ants are common hitchhiker pests on traded agricultural commodities that could be controlled by postharvest irradiation treatment. We studied radiation tolerance in queens of the red imported fire ant Solenopsis invicta Buren to determine the dose sufficient for its control. Virgin or fertile queens...

  15. Anthocyanin Extracted from Black Soybean Seed Coats Prevents Autoimmune Arthritis by Suppressing the Development of Th17 Cells and Synthesis of Proinflammatory Cytokines by Such Cells, via Inhibition of NF-κB.

    Directory of Open Access Journals (Sweden)

    Hong Ki Min

    Full Text Available Oxidative stress plays a role in the pathogenesis of rheumatoid arthritis (RA. Anthocyanin is a plant antioxidant. We investigated the therapeutic effects of anthocyanin extracted from black soybean seed coats (AEBS in a murine model of collagen-induced arthritis (CIA and human peripheral blood mononuclear cells (PBMCs and explored possible mechanisms by which AEBS might exert anti-arthritic effects.CIA was induced in DBA/1J mice. Cytokine levels were measured via enzyme-linked immunosorbent assays. Joints were assessed in terms of arthritis incidence, clinical arthritis scores, and histological features. The extent of oxidative stress in affected joints was determined by measuring the levels of nitrotyrosine and inducible nitric oxide synthase. NF-κB activity was assayed by measuring the ratio of phosphorylated IκB to total IκB via Western blotting. Th17 cells were stained with antibodies against CD4, IL-17, and STAT3. Osteoclast formation was assessed via TRAP staining and measurement of osteoclast-specific mRNA levels.In the CIA model, AEBS decreased the incidence of arthritis, histological inflammation, cartilage scores, and oxidative stress. AEBS reduced the levels of proinflammatory cytokines in affected joints of CIA mice and suppressed NF-κB signaling. AEBS decreased Th17 cell numbers in spleen of CIA mice. Additionally, AEBS repressed differentiation of Th17 cells and expression of Th17-associated genes in vitro, in both splenocytes of naïve DBA/1J mice and human PBMCs. In vitro, the numbers of both human and mouse tartrate-resistant acid phosphatase+ (TRAP multinucleated cells fell, in a dose-dependent manner, upon addition of AEBS.The anti-arthritic effects of AEBS were associated with decreases in Th17 cell numbers, and the levels of proinflammatory cytokines synthesized by such cells, mediated via suppression of NF-κB signaling. Additionally, AEBS suppressed osteoclastogenesis and reduced oxidative stress levels.

  16. Utilisation of multiple queens and pupae transplantation to boost early colony growth of weaver ants Oecophylla smaragdina

    DEFF Research Database (Denmark)

    Peng, Renkang; Nielsen, Mogens Gissel; Offenberg, Joachim

    2013-01-01

    Weaver ants (Oecophylla smaragdina Fabricius) have been increasingly used as biocontrol agents of insect pests and as insect protein for human food and animals. For either of these purposes, mature ant colonies are essential. However, for a newly established colony to develop to a suitable mature...... donor colony was conducted in 2010 at Darwin, Australia. The survival rates of the imago workers from transplanted pupae ranged between 73 - 97%, suggesting that queens in incipient colonies accepted foreign pupae. Colony size was positively related to the number of founding queens. Compared...

  17. A General Class of Test Statistics for Van Valen's Red Queen Hypothesis.

    Science.gov (United States)

    Wiltshire, Jelani; Huffer, Fred W; Parker, William C

    2014-09-01

    Van Valen's Red Queen hypothesis states that within a homogeneous taxonomic group the age is statistically independent of the rate of extinction. The case of the Red Queen hypothesis being addressed here is when the homogeneous taxonomic group is a group of similar species. Since Van Valen's work, various statistical approaches have been used to address the relationship between taxon age and the rate of extinction. We propose a general class of test statistics that can be used to test for the effect of age on the rate of extinction. These test statistics allow for a varying background rate of extinction and attempt to remove the effects of other covariates when assessing the effect of age on extinction. No model is assumed for the covariate effects. Instead we control for covariate effects by pairing or grouping together similar species. Simulations are used to compare the power of the statistics. We apply the test statistics to data on Foram extinctions and find that age has a positive effect on the rate of extinction. A derivation of the null distribution of one of the test statistics is provided in the supplementary material.

  18. The Red Queen and the persistence of linkage-disequilibrium oscillations in finite and infinite populations.

    Science.gov (United States)

    Kouyos, Roger D; Salathé, Marcel; Bonhoeffer, Sebastian

    2007-11-06

    The Red Queen Hypothesis (RQH) suggests that the coevolutionary dynamics of host-parasite systems can generate selection for increased host recombination. Since host-parasite interactions often have a strong genetic basis, recombination between different hosts can increase the fraction of novel and potentially resistant offspring genotypes. A prerequisite for this mechanism is that host-parasite interactions generate persistent oscillations of linkage disequilibria (LD). We use deterministic and stochastic models to investigate the persistence of LD oscillations and its impact on the RQH. The standard models of the Red Queen dynamics exhibit persistent LD oscillations under most circumstances. Here, we show that altering the standard model from discrete to continuous time or from simultaneous to sequential updating results in damped LD oscillations. This suggests that LD oscillations are structurally not robust. We then show that in a stochastic regime, drift can counteract this dampening and maintain the oscillations. In addition, we show that the amplitude of the oscillations and therefore the strength of the resulting selection for or against recombination are inversely proportional to the size of the (host) population. We find that host parasite-interactions cannot generally maintain oscillations in the absence of drift. As a consequence, the RQH can strongly depend on population size and should therefore not be interpreted as a purely deterministic hypothesis.

  19. The red queen coupled with directional selection favours the evolution of sex.

    Science.gov (United States)

    Hodgson, E E; Otto, S P

    2012-04-01

    Why sexual reproduction has evolved to be such a widespread mode of reproduction remains a major question in evolutionary biology. Although previous studies have shown that increased sex and recombination can evolve in the presence of host-parasite interactions (the 'Red Queen hypothesis' for sex), many of these studies have assumed that multiple loci mediate infection vs. resistance. Data suggest, however, that a major locus is typically involved in antigen presentation and recognition. Here, we explore a model where only one locus mediates host-parasite interactions, but a second locus is subject to directional selection. Even though the effects of these genes on fitness are independent, we show that increased rates of sex and recombination are favoured at a modifier gene that alters the rate of genetic mixing. This result occurs because of selective interference in finite populations (the 'Hill-Robertson effect'), which also favours sex. These results suggest that the Red Queen hypothesis may help to explain the evolution of sex by contributing a form of persistent selection, which interferes with directional selection at other loci and thereby favours sex and recombination. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  20. The Red Queen and the persistence of linkage-disequilibrium oscillations in finite and infinite populations

    Directory of Open Access Journals (Sweden)

    Bonhoeffer Sebastian

    2007-11-01

    Full Text Available Abstract Background The Red Queen Hypothesis (RQH suggests that the coevolutionary dynamics of host-parasite systems can generate selection for increased host recombination. Since host-parasite interactions often have a strong genetic basis, recombination between different hosts can increase the fraction of novel and potentially resistant offspring genotypes. A prerequisite for this mechanism is that host-parasite interactions generate persistent oscillations of linkage disequilibria (LD. Results We use deterministic and stochastic models to investigate the persistence of LD oscillations and its impact on the RQH. The standard models of the Red Queen dynamics exhibit persistent LD oscillations under most circumstances. Here, we show that altering the standard model from discrete to continuous time or from simultaneous to sequential updating results in damped LD oscillations. This suggests that LD oscillations are structurally not robust. We then show that in a stochastic regime, drift can counteract this dampening and maintain the oscillations. In addition, we show that the amplitude of the oscillations and therefore the strength of the resulting selection for or against recombination are inversely proportional to the size of the (host population. Conclusion We find that host parasite-interactions cannot generally maintain oscillations in the absence of drift. As a consequence, the RQH can strongly depend on population size and should therefore not be interpreted as a purely deterministic hypothesis.

  1. Differences between selection on sex versus recombination in red queen models with diploid hosts.

    Science.gov (United States)

    Agrawal, Aneil F

    2009-08-01

    The Red Queen hypothesis argues that parasites generate selection for genetic mixing (sex and recombination) in their hosts. A number of recent papers have examined this hypothesis using models with haploid hosts. In these haploid models, sex and recombination are selectively equivalent. However, sex and recombination are not equivalent in diploids because selection on sex depends on the consequences of segregation as well as recombination. Here I compare how parasites select on modifiers of sexual reproduction and modifiers of recombination rate. Across a wide set of parameters, parasites tend to select against both sex and recombination, though recombination is favored more often than is sex. There is little correspondence between the conditions favoring sex and those favoring recombination, indicating that the direction of selection on sex is often determined by the effects of segregation, not recombination. Moreover, when sex was favored it is usually due to a long-term advantage whereas short-term effects are often responsible for selection favoring recombination. These results strongly indicate that Red Queen models focusing exclusively on the effects of recombination cannot be used to infer the type of selection on sex that is generated by parasites on diploid hosts.

  2. The Red Queen in mitochondria: cyto-nuclear co-evolution, hybrid breakdown and human disease

    Directory of Open Access Journals (Sweden)

    Jui-Yu eChou

    2015-05-01

    Full Text Available Cyto-nuclear incompatibility, a specific form of Dobzhansky-Muller incompatibility caused by incompatible alleles between mitochondrial and nuclear genomes, has been suggested to play a critical role during speciation. Several features of the mitochondrial genome (mtDNA, including high mutation rate, dynamic genomic structure, and uniparental inheritance, make mtDNA more likely to accumulate mutations in the population. Once mtDNA has changed, the nuclear genome needs to play catch-up due to the intimate interactions between these two genomes. In two populations, if cyto-nuclear co-evolution is driven in different directions, it may eventually lead to hybrid incompatibility. Although cyto-nuclear incompatibility has been observed in a wide range of organisms, it remains unclear what type of mutations drives the co-evolution. Currently, evidence supporting adaptive mutations in mtDNA remains limited. On the other hand, it has been known that some mutations allow mtDNA to propagate more efficiently but compromise the host fitness (described as selfish mtDNA. Arms races between such selfish mtDNA and host nuclear genomes can accelerate cyto-nuclear co-evolution and lead to a phenomenon called the Red Queen Effect. Here, we discuss how the Red Queen Effect may contribute to the frequent observation of cyto-nuclear incompatibility and be the underlying driving force of some human mitochondrial diseases.

  3. The Red Queen in mitochondria: cyto-nuclear co-evolution, hybrid breakdown and human disease.

    Science.gov (United States)

    Chou, Jui-Yu; Leu, Jun-Yi

    2015-01-01

    Cyto-nuclear incompatibility, a specific form of Dobzhansky-Muller incompatibility caused by incompatible alleles between mitochondrial and nuclear genomes, has been suggested to play a critical role during speciation. Several features of the mitochondrial genome (mtDNA), including high mutation rate, dynamic genomic structure, and uniparental inheritance, make mtDNA more likely to accumulate mutations in the population. Once mtDNA has changed, the nuclear genome needs to play catch-up due to the intimate interactions between these two genomes. In two populations, if cyto-nuclear co-evolution is driven in different directions, it may eventually lead to hybrid incompatibility. Although cyto-nuclear incompatibility has been observed in a wide range of organisms, it remains unclear what type of mutations drives the co-evolution. Currently, evidence supporting adaptive mutations in mtDNA remains limited. On the other hand, it has been known that some mutations allow mtDNA to propagate more efficiently but compromise the host fitness (described as selfish mtDNA). Arms races between such selfish mtDNA and host nuclear genomes can accelerate cyto-nuclear co-evolution and lead to a phenomenon called the Red Queen Effect. Here, we discuss how the Red Queen Effect may contribute to the frequent observation of cyto-nuclear incompatibility and be the underlying driving force of some human mitochondrial diseases.

  4. Drone exposure to the systemic insecticide Fipronil indirectly impairs queen reproductive potential.

    Science.gov (United States)

    Kairo, Guillaume; Provost, Bertille; Tchamitchian, Sylvie; Ben Abdelkader, Faten; Bonnet, Marc; Cousin, Marianne; Sénéchal, Jacques; Benet, Pauline; Kretzschmar, André; Belzunces, Luc P; Brunet, Jean-Luc

    2016-08-23

    A species that requires sexual reproduction but cannot reproduce is doomed to extinction. The important increasing loss of species emphasizes the ecological significance of elucidating the effects of environmental stressors, such as pesticides, on reproduction. Despite its special reproductive behavior, the honey bee was selected as a relevant and integrative environmental model because of its constant and diverse exposure to many stressors due to foraging activity. The widely used insecticide Fipronil, the use of which is controversial because of its adverse effects on honey bees, was chosen to expose captive drones in hives via syrup contaminated at 0.1 μg/L and gathered by foragers. Such environmental exposure led to decreased spermatozoa concentration and sperm viability coupled with an increased sperm metabolic rate, resulting in drone fertility impairment. Subsequently, unexposed queens inseminated with such sperm exhibited fewer spermatozoa with lower viability in their spermatheca, leaving no doubt about the detrimental consequences for the reproductive potential of queens, which are key for colony sustainability. These findings suggest that pesticides could contribute to declining honey bee populations through fertility impairment, as exemplified by Fipronil. More broadly, reproductive disorders should be taken into consideration when investigating the decline of other species.

  5. Induced chlorophyll variation in pineapple c v. 'queen' by gamma irradiation (60Cobalt)

    International Nuclear Information System (INIS)

    Valencia, Lolita DC.

    2012-01-01

    Irradiation using gamma rays ( 60 Cobalt) coupled with in vitro culture techniques was undertaken to induce variation or mutation in pineapple. Calli from crown meristem tips of pineapple cv 'Queen' [Ananas comosus (L.) Merr.] were initiated using Murashiege and Skoog's basal meduim supplemented with 10mg/liter 4-amino-3,5,6-trichloro-2-pyrodinecarboxylic acid (Picloram). High percentage of growth and shoot proliferation was observed in basal medium supplemented with 50 μM benzene adenine purine (BAP) and 10 μM gibberrelic acid (GA) after 8 weeks in vitro. Regenerants derived from shoots using different doses of gamma rays (0, 5, 10, 15, 20, 25 and 30 Gy) were evaluated under laboratory conditions. Of the different doses, 15 Gy produced the most variegation in young shoots (chlorophyll variants) maintained in vitro. The variants appeared to have yellow and green color combinations of the young leaves of pineapple 'Queen' variety. When transplanted inside the greenhouse, high percentage of plantlets survival was observed, ranging from 90-95%. Of the different irradiation doses, variegation in young leaves was observed at 15, 20, 25 and 30 Gy. Further assessment on the effect of irradiation is currently being unertaken under screen house conditions. The variants produced could serve a basis for selection of ornamental-type pineapple. In addition, protocols developed on the use of in vitro culture techniques could be utilized as a tool for induced mutation breeding in pineapple. (author)

  6. Temperature and Snowfall in Western Queen Maud Land Increasing Faster Than Climate Model Projections

    Science.gov (United States)

    Medley, B.; McConnell, J. R.; Neumann, T. A.; Reijmer, C. H.; Chellman, N.; Sigl, M.; Kipfstuhl, S.

    2018-02-01

    East Antarctic Ice Sheet (EAIS) mass balance is largely driven by snowfall. Recently, increased snowfall in Queen Maud Land led to years of EAIS mass gain. It is difficult to determine whether these years of enhanced snowfall are anomalous or part of a longer-term trend, reducing our ability to assess the mitigating impact of snowfall on sea level rise. We determine that the recent snowfall increases in western Queen Maud Land (QML) are part of a long-term trend (+5.2 ± 3.7% decade-1) and are unprecedented over the past two millennia. Warming between 1998 and 2016 is significant and rapid (+1.1 ± 0.7°C decade-1). Using these observations, we determine that the current accumulation and temperature increases in QML from an ensemble of global climate simulations are too low, which suggests that projections of the QML contribution to sea level rise are potentially overestimated with a reduced mitigating impact of enhanced snowfall in a warming world.

  7. Drone exposure to the systemic insecticide Fipronil indirectly impairs queen reproductive potential

    Science.gov (United States)

    Kairo, Guillaume; Provost, Bertille; Tchamitchian, Sylvie; Ben Abdelkader, Faten; Bonnet, Marc; Cousin, Marianne; Sénéchal, Jacques; Benet, Pauline; Kretzschmar, André; Belzunces, Luc P.; Brunet, Jean-Luc

    2016-01-01

    A species that requires sexual reproduction but cannot reproduce is doomed to extinction. The important increasing loss of species emphasizes the ecological significance of elucidating the effects of environmental stressors, such as pesticides, on reproduction. Despite its special reproductive behavior, the honey bee was selected as a relevant and integrative environmental model because of its constant and diverse exposure to many stressors due to foraging activity. The widely used insecticide Fipronil, the use of which is controversial because of its adverse effects on honey bees, was chosen to expose captive drones in hives via syrup contaminated at 0.1 μg/L and gathered by foragers. Such environmental exposure led to decreased spermatozoa concentration and sperm viability coupled with an increased sperm metabolic rate, resulting in drone fertility impairment. Subsequently, unexposed queens inseminated with such sperm exhibited fewer spermatozoa with lower viability in their spermatheca, leaving no doubt about the detrimental consequences for the reproductive potential of queens, which are key for colony sustainability. These findings suggest that pesticides could contribute to declining honey bee populations through fertility impairment, as exemplified by Fipronil. More broadly, reproductive disorders should be taken into consideration when investigating the decline of other species. PMID:27549030

  8. Drone exposure to the systemic insecticide Fipronil indirectly impairs queen reproductive potential

    Science.gov (United States)

    Kairo, Guillaume; Provost, Bertille; Tchamitchian, Sylvie; Ben Abdelkader, Faten; Bonnet, Marc; Cousin, Marianne; Sénéchal, Jacques; Benet, Pauline; Kretzschmar, André; Belzunces, Luc P.; Brunet, Jean-Luc

    2016-08-01

    A species that requires sexual reproduction but cannot reproduce is doomed to extinction. The important increasing loss of species emphasizes the ecological significance of elucidating the effects of environmental stressors, such as pesticides, on reproduction. Despite its special reproductive behavior, the honey bee was selected as a relevant and integrative environmental model because of its constant and diverse exposure to many stressors due to foraging activity. The widely used insecticide Fipronil, the use of which is controversial because of its adverse effects on honey bees, was chosen to expose captive drones in hives via syrup contaminated at 0.1 μg/L and gathered by foragers. Such environmental exposure led to decreased spermatozoa concentration and sperm viability coupled with an increased sperm metabolic rate, resulting in drone fertility impairment. Subsequently, unexposed queens inseminated with such sperm exhibited fewer spermatozoa with lower viability in their spermatheca, leaving no doubt about the detrimental consequences for the reproductive potential of queens, which are key for colony sustainability. These findings suggest that pesticides could contribute to declining honey bee populations through fertility impairment, as exemplified by Fipronil. More broadly, reproductive disorders should be taken into consideration when investigating the decline of other species.

  9. Increased oxidative stress and decreased activities of Ca2+/Mg2+-ATPase and Na+/K+-ATPase in the red blood cells of the hibernating black bear

    Science.gov (United States)

    Chauhan, V.P.S.; Tsiouris, J.A.; Chauhan, A.; Sheikh, A.M.; Brown, W. Ted; Vaughan, M.

    2002-01-01

    During hibernation, animals undergo metabolic changes that result in reduced utilization of glucose and oxygen. Fat is known to be the preferential source of energy for hibernating animals. Malonyldialdehyde (MDA) is an end product of fatty acid oxidation, and is generally used as an index of lipid peroxidation. We report here that peroxidation of lipids is increased in the plasma and in the membranes of red blood cells in black bears during hibernation. The plasma MDA content was about four fold higher during hibernation as compared to that during the active, non-hibernating state (P hibernation (P hibernating state as compared to the active state. Na+/K+-ATPase activity was also decreased, though not significant, during hibernation. These results suggest that during hibernation, the bears are under increased oxidative stress, and have reduced activities of membrane-bound enzymes such as Ca2+/Mg2+-ATPase and Na+/K+-ATPase. These changes can be considered part of the adaptive for survival process of metabolic depression. ?? 2002 Elsevier Science Inc. All rights reserved.

  10. Increased oxidative stress and decreased activities of Ca(2+)/Mg(2+)-ATPase and Na(+)/K(+)-ATPase in the red blood cells of the hibernating black bear.

    Science.gov (United States)

    Chauhan, Ved P S; Tsiouris, John A; Chauhan, Abha; Sheikh, Ashfaq M; Brown, W Ted; Vaughan, Michael

    2002-05-31

    During hibernation, animals undergo metabolic changes that result in reduced utilization of glucose and oxygen. Fat is known to be the preferential source of energy for hibernating animals. Malonyldialdehyde (MDA) is an end product of fatty acid oxidation, and is generally used as an index of lipid peroxidation. We report here that peroxidation of lipids is increased in the plasma and in the membranes of red blood cells in black bears during hibernation. The plasma MDA content was about four fold higher during hibernation as compared to that during the active, non-hibernating state (P hibernation (P hibernating state as compared to the active state. Na(+)/K(+)-ATPase activity was also decreased, though not significant, during hibernation. These results suggest that during hibernation, the bears are under increased oxidative stress, and have reduced activities of membrane-bound enzymes such as Ca(2+)/Mg(2+)-ATPase and Na(+)/K(+)-ATPase. These changes can be considered part of the adaptive for survival process of metabolic depression.

  11. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.

    1980-01-01

    Conditions for the formation of a black hole are considered, and the properties of black holes. The possibility of Cygnus X-1 as a black hole is discussed. Einstein's theory of general relativity in relation to the formation of black holes is discussed. (U.K.)

  12. Black Eye: First Aid

    Science.gov (United States)

    First aid Black eye Black eye: First aid By Mayo Clinic Staff A black eye is caused by bleeding under the skin around the eye. Most injuries that cause a ... 13, 2018 Original article: http://www.mayoclinic.org/first-aid/first-aid-black-eye/basics/ART-20056675 . Mayo ...

  13. Ground-water and geohydrologic conditions in Queens County, Long Island, New York

    Science.gov (United States)

    Soren, Julian

    1971-01-01

    Queens County is a heavily populated borough of New York City, at the western end of Long Island, N. Y., in which large amounts of ground water are used, mostly for public supply. Ground water, pumped from local aquifers, by privately owned water-supply companies, supplied the water needs of about 750,000 of the nearly 2 million residents of the county in 1967; the balance was supplied by New York City from surface sources outside the county in upstate New York. The county's aquifers consist of sand and gravel of Late Cretaceous and of Pleistocene ages, and the aquifers comprise a wedge-shaped ground-water reservoir lying on a southeastward-sloping floor of Precambrian(?) bedrock. Beds of clay and silt generally confine water in the deeper parts of the reservoir; water in the deeper aquifers ranges from poorly confined to well confined. Wisconsin-age glacial deposits in the uppermost part of the reservoir contain ground water under water-table conditions. Ground water pumpage averaged about 60 mgd (million gallons per day) in Queens County from about 1900 to 1967. Much of the water was used in adjacent Kings County, another borough of New York City, prior to 1950. The large ground-water withdrawal has resulted in a wide-spread and still-growing cone of depression in the water table, reflecting a loss of about 61 billion gallons of fresh water from storage. Significant drawdown of the water table probably began with rapid urbanization of Queens County in the 1920's. The county has been extensively paved, and storm and sanitary sewers divert water, which formerly entered the ground, to tidewater north and south of the county. Natural recharge to the aquifers has been reduced to about one half of the preurban rate and is below the withdrawal rate. Ground-water levels have declined more than 40. feet from the earliest-known levels, in 1903, to 1967, and the water table is below sea level in much of the county. The aquifers are being contaminated by the movement of

  14. NJEMANZE QUEEN

    African Journals Online (AJOL)

    user

    safeguards our values and experiences, our stories and artifacts and encourages continuity. The world is dynamic, it is going global; the introduction of the information ..... Ndukwe, E. (2007) “How ICT Drives the New Economy” in Daily Sun 12/11/07p.35. Njemanze, Q. (2007) “Language Endangerment: A Phenomenon of ...

  15. Drama Queen

    Science.gov (United States)

    Carpenter, Angelica Shirley

    2006-01-01

    This article presents an interview with Jacqueline Wilson, a popular British author of children's books. Wilson has published 86 books for children and young adults with more than 20 million copies sold in the U.K. alone. Wilson's fans--mostly seven- to 14-year-old girls--love her gripping plots about dysfunctional families, homelessness, and…

  16. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M

    2003-01-01

    Methods and results of searching for stellar mass black holes in binary systems and for supermassive black holes in galactic nuclei of different types are described. As of now (June 2002), a total of 100 black hole candidates are known. All the necessary conditions Einstein's General Relativity imposes on the observational properties of black holes are satisfied for candidate objects available, thus further assuring the existence of black holes in the Universe. Prospects for obtaining sufficient criteria for reliably distinguishing candidate black holes from real black holes are discussed. (reviews of topical problems)

  17. Finding out egyptian gods' secret using analytical chemistry: biomedical properties of egyptian black makeup revealed by amperometry at single cells.

    Science.gov (United States)

    Tapsoba, Issa; Arbault, Stéphane; Walter, Philippe; Amatore, Christian

    2010-01-15

    Lead-based compounds were used during antiquity as both pigments and medicines in the formulation of makeup materials. Chemical analysis of cosmetics samples found in Egyptians tombs and the reconstitution of ancient recipes as reported by Greco-Roman authors have shown that two non-natural lead chlorides (laurionite Pb(OH)Cl and phosgenite Pb(2)Cl(2)CO(3)) were purposely synthesized and were used as fine powders in makeup and eye lotions. According to ancient Egyptian manuscripts, these were essential remedies for treating eye illness and skin ailments. This conclusion seems amazing because today we focus only on the well-recognized toxicity of lead salts. Here, using ultramicroelectrodes, we obtain new insights into the biochemical interactions between lead(II) ions and cells, which support the ancient medical use of sparingly soluble lead compounds. Submicromolar concentrations of Pb(2+) ions are shown to be sufficient for eliciting specific oxidative stress responses of keratinocytes. These consist essentially of an overproduction of nitrogen monoxide (NO degrees ). Owing to the biological role of NO degrees in stimulating nonspecific immunological defenses, one may argue that these lead compounds were deliberately manufactured and used in ancient Egyptian formulations to prevent and treat eye illnesses by promoting the action of immune cells.

  18. Parthenogenetic flatworms have more symbionts than their coexisting, sexual conspecifics, but does this support the Red Queen?

    NARCIS (Netherlands)

    Michiels, N.K.; Beukeboom, L.W.; Pongratz, N.; Zeitlinger, J.

    2001-01-01

    The Red Queen hypothesis predicts that sexuality is favoured when virulent parasites adapt quickly to host genotypes. We studied a population of the flatworm Schmidtea polychroa in which obligate sexual and parthenogenetic individuals coexist. Infection rates by an amoeboid protozoan were

  19. Queen survival and oxalic acid residues in sugar stores after summer application against Varroa destructor in honey bees (Apis mellifera)

    NARCIS (Netherlands)

    Cornelissen, B.; Donders, J.N.L.C.; Stratum, van P.; Blacquière, T.; Dooremalen, van C.

    2012-01-01

    Methods using oxalic acid (OA) to control Varroa destructor in honey bee (Apis mellifera) colonies are widely applied. In this study, the effects of an OA spray application in early summer on the survival of young and old queens, and on OA residues in sugar stores were investigated. A questionnaire

  20. Morphometric study of newly emerged unmated queens of honey bee Apis mellifera L. in Ismailia Governorate, Egypt

    Directory of Open Access Journals (Sweden)

    S.M. Kamel

    2013-06-01

    Full Text Available Recently, morphometric analysis is being a very good tool for identification of honey bee races and characterization of genetic materials. This fact has motivated the present work to investigate the effects of two grafting methods, three types of artificial queen wax cups and four periods of queen rearing on some morphological characters of newly emerged queens. The developed technique used in the present study depends on the integration between Scanner unit and Photoshop program, called Scan Photo Method (SPM. The measurements of 23 morphological characteristics of reared queens were estimated by using SPM. Results indicated significant differences between periods in the measurements of the studied characteristics on forewing such as cubital index, distance C, distance D, radial field, inner wing length, inner wing width, dumb bell index, distance I, II, III and IV, except cubital A and cubital B. Regarding the effects of cup types and grafting methods, data also revealed significant differences in all measurements of studied characteristics, except tibial length, hind wing length, cubital B, radial field and distance IV. Further works in this area were recommended to find out a relation between some morphometric characters and important of some quantitative characters.

  1. 76 FR 68711 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-11-07

    .... 101217620-1654-02] RIN 0648-BA62 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef... fisheries are managed under the FMP for Reef Fish and the FMP for Coral and Reef Associated Plants and... Amendment 6 to the Fishery Management Plan (FMP) for the Reef Fish Fishery of Puerto Rico and the U.S...

  2. 76 FR 59377 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-09-26

    ...-BA62 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and... within the Reef Fish FMP and the Coral and Reef Associated Plants and Invertebrates FMP, revise the... alternatives to redefine the management of aquarium trade species within the Reef Fish FMP and within the Coral...

  3. 76 FR 23907 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto...

    Science.gov (United States)

    2011-04-29

    ..., Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto Rico and the U.S. Virgin Islands..., 263 13th Avenue South, St. Petersburg, FL 33701 or may be downloaded from the Southeast Regional... approximately $39,000. Even this value, as an extreme upper bound for average revenues for St. Croix fishermen...

  4. Differential effects of insemination volume and substance on reproductive changes in honey bee queens (Apis mellifera L.).

    Science.gov (United States)

    Niño, E L; Tarpy, D R; Grozinger, C M

    2013-06-01

    Mating causes dramatic changes in female insects at the behavioural, physiological and molecular level. The factors driving these changes (e.g. seminal proteins, seminal volume) and the molecular pathways by which these factors are operating have been characterized only in a handful of insect species. In the present study, we use instrumental insemination of honey bee queens to examine the role of the insemination substance and volume in triggering post-mating changes. We also examine differences in gene expression patterns in the fat bodies of queens with highly activated ovaries to determine if events during copulation can cause long-term changes in gene expression. We found that the instrumental insemination procedure alone caused cessation of mating flights and triggered ovary activation, with high-volume inseminated queens having the greatest ovary activation. Hierarchical clustering grouped queens primarily by insemination substance and then insemination volume, suggesting that while volume may trigger short-term physiological changes (i.e. ovary activation) substance plays a greater role in regulating long-term transcriptional changes. The results of gene ontology analysis and comparison with previous studies suggest that both insemination substance and volume trigger molecular post-mating changes by altering overlapping gene pathways involved in honey bee reproduction. We also discuss the effects on two genes (vitellogenin and transferrin) involved in reproduction and defence responses. © 2013 Royal Entomological Society.

  5. Tapping Teen Talent in Queens: A Library-Based, LSCA-Funded Youth Development Success Story from New York.

    Science.gov (United States)

    Williams, Barbara Osborne

    1996-01-01

    Describes a program developed by the Youth Services Division at the Queens Borough Public Library's Central Library to help teenagers maximize growth opportunities, build self-esteem, and see the library as a life resource. Highlights include securing funding through LSCA (Library Services and Construction Act), recruiting participants, and…

  6. 76 FR 59375 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and...

    Science.gov (United States)

    2011-09-26

    ... complexes that are classified as undergoing overfishing or that contain sub-units which are classified as undergoing overfishing (i.e. snapper, grouper and parrotfish); allocate ACLs among island management areas... parrotfishes. The intended effects of Amendments 2 and 5 are to prevent overfishing of queen conch and reef...

  7. How the clinical customization of an EMR means good business: a case study of Queen City Physicians.

    Science.gov (United States)

    Coyle-Toerner, Pam; Collins, Louise

    2003-01-01

    This article describes a case study of Queen City Physicians, a 38-provider internal medicine and pediatrics practice spread over eight locations in the Cincinnati, OH area. The authors share steps taken and lessons learned that can ensure success for any small to medium practice, from vendor/system selection to go-live. The financial feasibility of EMR systems is also discussed.

  8. 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

    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 sugg...

  9. Male scent-marking pheromone of Bombus ardens ardens (Hymenoptera; Apidae) attracts both conspecific queens and males

    Science.gov (United States)

    Kubo, Ryohei; Harano, Ken-ichi; Ono, Masato

    2017-10-01

    To explore the role of the volatiles emitted from male labial gland (LG) of the bumblebee Bombus ardens ardens, we investigated the responses of virgin queens and males to volatiles using a gas chromatography-electroantennographic detector (GC-EAD) system and Y-tube olfactometer. GC-EAD analysis revealed that citronellol, the main compound detected in the male LG, caused clear electrophysiological responses in the antennae of B. a. ardens virgin queens and males although two minor compounds elicited antennal responses when applied in a high concentration. Behavioral tests using a Y-tube olfactometer showed that queens and males were significantly attracted to both LG extracts and citronellol more than to the solvent alone. This is the first study to demonstrate that citronellol as a major compound of male scent-marking pheromone in B. a. ardens functions as a sex attractant for queens. The results also suggest that this compound has another function as a trail marker used by males.

  10. Report from the 2nd Summer School in Computational Biology organized by the Queen's University of Belfast

    Directory of Open Access Journals (Sweden)

    Frank Emmert-Streib

    2014-12-01

    Full Text Available In this paper, we present a meeting report for the 2nd Summer School in Computational Biology organized by the Queen's University of Belfast. We describe the organization of the summer school, its underlying concept and student feedback we received after the completion of the summer school.

  11. Brane world black rings

    International Nuclear Information System (INIS)

    Sahay, Anurag; Sengupta, Gautam

    2007-01-01

    Five dimensional neutral rotating black rings are described from a Randall-Sundrum brane world perspective in the bulk black string framework. To this end we consider a rotating black string extension of a five dimensional black ring into the bulk of a six dimensional Randall-Sundrum brane world with a single four brane. The bulk solution intercepts the four brane in a five dimensional black ring with the usual curvature singularity on the brane. The bulk geodesics restricted to the plane of rotation of the black ring are constructed and their projections on the four brane match with the usual black ring geodesics restricted to the same plane. The asymptotic nature of the bulk geodesics are elucidated with reference to a bulk singularity at the AdS horizon. We further discuss the description of a brane world black ring as a limit of a boosted bulk black 2 brane with periodic identification

  12. The effects of black garlic ethanol extract on the spatial memory and estimated total number of pyramidal cells of the hippocampus of monosodium glutamate-exposed adolescent male Wistar rats.

    Science.gov (United States)

    Hermawati, Ery; Sari, Dwi Cahyani Ratna; Partadiredja, Ginus

    2015-09-01

    Monosodium glutamate (MSG) is believed to exert deleterious effects on various organs, including the hippocampus, likely via the oxidative stress pathway. Garlic (Alium sativum L.), which is considered to possess potent antioxidant activity, has been used as traditional remedy for various ailments since ancient times. We have investigated the effects of black garlic, a fermented form of garlic, on spatial memory and estimated the total number of pyramidal cells of the hippocampus in adolescent male Wistar rats treated with MSG. Twenty-five rats were divided into five groups: C- group, which received normal saline; C+ group, which was exposed to 2 mg/g body weight (bw) of MSG; three treatment groups (T2.5, T5, T10), which were treated with black garlic extract (2.5, 5, 10 mg/200 g bw, respectively) and MSG. The spatial memory test was carried out using the Morris water maze (MWM) procedure, and the total number of pyramidal cells of the hippocampus was estimated using the physical disector design. The groups treated with black garlic extract were found to have a shorter path length than the C- and C+ groups in the escape acquisition phase of the MWM test. The estimated total number of pyramidal cells in the CA1 region of the hippocampus was higher in all treated groups than that of the C+ group. Based on these results, we conclude that combined administration of black garlic and MSG may alter the spatial memory functioning and total number of pyramidal neurons of the CA1 region of the hippocampus of rats.

  13. Chronic exposure of imidacloprid and clothianidin reduce queen survival, foraging, and nectar storing in colonies of Bombus impatiens.

    Directory of Open Access Journals (Sweden)

    Jamison Scholer

    Full Text Available In an 11-week greenhouse study, caged queenright colonies of Bombus impatiens Cresson, were fed treatments of 0 (0 ppb actual residue I, imidacloprid; C, clothianidin, 10 (14 I, 9 C, 20 (16 I, 17C, 50 (71 I, 39 C and 100 (127 I, 76 C ppb imidacloprid or clothianidin in sugar syrup (50%. These treatments overlapped the residue levels found in pollen and nectar of many crops and landscape plants, which have higher residue levels than seed-treated crops (less than 10 ppb, corn, canola and sunflower. At 6 weeks, queen mortality was significantly higher in 50 ppb and 100 ppb and by 11 weeks in 20 ppb-100 ppb neonicotinyl-treated colonies. The largest impact for both neonicotinyls starting at 20 (16 I, 17 C ppb was the statistically significant reduction in queen survival (37% I, 56% C ppb, worker movement, colony consumption, and colony weight compared to 0 ppb treatments. Bees at feeders flew back to the nest box so it appears that only a few workers were collecting syrup in the flight box and returning the syrup to the nest. The majority of the workers sat immobilized for weeks on the floor of the flight box without moving to fed at sugar syrup feeders. Neonicotinyl residues were lower in wax pots in the nest than in the sugar syrup that was provided. At 10 (14 ppb I and 50 (39 ppb C, fewer males were produced by the workers, but queens continued to invest in queen production which was similar among treatments. Feeding on imidacloprid and clothianidin can cause changes in behavior (reduced worker movement, consumption, wax pot production, and nectar storage that result in detrimental effects on colonies (queen survival and colony weight. Wild bumblebees depending on foraging workers can be negatively impacted by chronic neonicotinyl exposure at 20 ppb.

  14. Chronic exposure of imidacloprid and clothianidin reduce queen survival, foraging, and nectar storing in colonies of Bombus impatiens.

    Science.gov (United States)

    Scholer, Jamison; Krischik, Vera

    2014-01-01

    In an 11-week greenhouse study, caged queenright colonies of Bombus impatiens Cresson, were fed treatments of 0 (0 ppb actual residue I, imidacloprid; C, clothianidin), 10 (14 I, 9 C), 20 (16 I, 17C), 50 (71 I, 39 C) and 100 (127 I, 76 C) ppb imidacloprid or clothianidin in sugar syrup (50%). These treatments overlapped the residue levels found in pollen and nectar of many crops and landscape plants, which have higher residue levels than seed-treated crops (less than 10 ppb, corn, canola and sunflower). At 6 weeks, queen mortality was significantly higher in 50 ppb and 100 ppb and by 11 weeks in 20 ppb-100 ppb neonicotinyl-treated colonies. The largest impact for both neonicotinyls starting at 20 (16 I, 17 C) ppb was the statistically significant reduction in queen survival (37% I, 56% C) ppb, worker movement, colony consumption, and colony weight compared to 0 ppb treatments. Bees at feeders flew back to the nest box so it appears that only a few workers were collecting syrup in the flight box and returning the syrup to the nest. The majority of the workers sat immobilized for weeks on the floor of the flight box without moving to fed at sugar syrup feeders. Neonicotinyl residues were lower in wax pots in the nest than in the sugar syrup that was provided. At 10 (14) ppb I and 50 (39) ppb C, fewer males were produced by the workers, but queens continued to invest in queen production which was similar among treatments. Feeding on imidacloprid and clothianidin can cause changes in behavior (reduced worker movement, consumption, wax pot production, and nectar storage) that result in detrimental effects on colonies (queen survival and colony weight). Wild bumblebees depending on foraging workers can be negatively impacted by chronic neonicotinyl exposure at 20 ppb.

  15. Natural Larval Diet Differently Influences the Pattern of Developmental Changes in DNA 5-Methylcytosine Levels in Apis mellifera Queens as Compared with Workers and Drones.

    Science.gov (United States)

    Strachecka, A; Olszewski, K; Bajda, M; Demetraki-Paleolog, J

    2015-08-01

    The principal mechanism of gene activation/silencing is DNA 5-methylcytosine methylation. This study was aimed at determining global DNA methylation levels in larvae, prepupae, pupae, and 1-day-old adults of Apis mellifera queens, workers and drones. The Imprint Methylated DNA Quantification Kit MDQ1 was used. Percentages of DNA 5-methylcytosine were low and relatively similar in the larvae of all the castes until 4th day of larval development (3-5%). However, they were higher in the drone and worker larvae than in the queen larvae. Generally, the developmental patterns of changes in the DNA methylation levels were different in the queens in comparison with the drones and workers. While methylation increased in the queens, it decreased in the drones and workers. Methylated DNA methylcytosine percentages and weights in the queen prepupae (15%, 9.18 ng) and pupae (21%, 10.74 ng) were, respectively, three and four times higher than in the worker/drone brood of the same age (2.5-4%, 0.03-0.07 ng). Only in the queens, after a substantial increase, did DNA methylation decrease almost twice between the pupal stage and queen emergence (from 21% and 10.74 ng to 12% and 6.78 ng). This finding seems very interesting, particularly for experimental gerontology.

  16. Cyber against punk: Greg Bear’s Queen of Angels as metamorphosed cyberpunk

    Directory of Open Access Journals (Sweden)

    M. F. Blatchford

    1994-05-01

    Full Text Available Recent American science fiction (which commercially dominates world science fiction incorporates two schools of thought, ‘cyberpunk' and ‘hard SF’. which may be read to embody, respectively, radical/liberal and patriotic/ conservative propaganda. This article, after attempting to define aspects of these schools, examines Queen of Angels by Greg Bear (who before producing that text had been a proponent of hard SF. This text is shown to have strong elements of cyberpunk (possibly, to judge by one critical review, appealing to a cyberpunk audience but to have transformed and inverted the radical and liberal themes of cyberpunk into conservative themes. The text thus illuminates philosophical and technical differences between the schools. It is suggested that the imagery of cyberpunk, and perhaps that of science fiction in general, is liable to such reversals of ideological significance.

  17. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...... is known to include evolutionarily derived genera with obligate multiple mating (the Acromyrmex and Atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. Apterostigma, Cyphomyrmex, Myrmicocrypta). All attine genera share the unique characteristic of obligate...... dependence on symbiotic fungus gardens for food, but the sophistication of this symbiosis differs considerably across genera. The lower attine genera generally have small, short-lived colonies and relatively non-specialized fungal symbionts (capable of living independently of their ant hosts), whereas...

  18. Volunteering as Red Queen Mechanism for Cooperation in Public Goods Games

    Science.gov (United States)

    Hauert, Christoph; De Monte, Silvia; Hofbauer, Josef; Sigmund, Karl

    2002-05-01

    The evolution of cooperation among nonrelated individuals is one of the fundamental problems in biology and social sciences. Reciprocal altruism fails to provide a solution if interactions are not repeated often enough or groups are too large. Punishment and reward can be very effective but require that defectors can be traced and identified. Here we present a simple but effective mechanism operating under full anonymity. Optional participation can foil exploiters and overcome the social dilemma. In voluntary public goods interactions, cooperators and defectors will coexist. We show that this result holds under very diverse assumptions on population structure and adaptation mechanisms, leading usually not to an equilibrium but to an unending cycle of adjustments (a Red Queen type of evolution). Thus, voluntary participation offers an escape hatch out of some social traps. Cooperation can subsist in sizable groups even if interactions are not repeated, defectors remain anonymous, players have no memory, and assortment is purely random.

  19. A mean field model for competition: from neutral ecology to the Red Queen.

    Science.gov (United States)

    O'Dwyer, James P; Chisholm, Ryan

    2014-08-01

    Individual species are distributed inhomogeneously over space and time, yet, within large communities of species, aggregated patterns of biodiversity seem to display nearly universal behaviour. Neutral models assume that an individual's demographic prospects are independent of its species identity. They have successfully predicted certain static, time-independent patterns. But they have generally failed to predict temporal patterns, such as species ages or population dynamics. We construct a new, multispecies framework incorporating competitive differences between species, and assess the impact of this competition on static and dynamic patterns of biodiversity. We solve this model exactly for the special case of a Red Queen hypothesis, where fitter species are continually arising. The model predicts more realistic species ages than neutral models, without greatly changing predictions for static species abundance distributions. Our modelling approach may allow users to incorporate a broad range of ecological mechanisms. © 2014 John Wiley & Sons Ltd/CNRS.

  20. Joint coevolutionary-epidemiological models dampen Red Queen cycles and alter conditions for epidemics.

    Science.gov (United States)

    MacPherson, Ailene; Otto, Sarah P

    2017-12-28

    Host-parasite interactions in the form of infectious diseases are a topic of interest in both evolutionary biology and public health. Both fields have relied on mathematical models to predict and understand the dynamics and consequences of these interactions. Yet few models explicitly incorporate both epidemiological and coevolutionary dynamics, allowing for genetic variation in both hosts and parasites. By comparing a matching-alleles model of coevolution, a susceptible-infected-recovered-susceptible compartmental model from epidemiology, and a combined coevolutionary-epidemiology model we assess the effect of the coevolutionary feedback on the epidemiological dynamics and vice versa. We find that Red-Queen cycles are not robust in an epidemiological framework and that coevolutionary interactions can alter the conditions under which epidemic cycles arise. Incorporating both explicit epidemiology and genetic diversity may have important implications for the maintenance of sexual reproduction as well as disease management. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A new nuclear materials laboratory at Queen's University

    Energy Technology Data Exchange (ETDEWEB)

    Holt, R.A.; Daymond, M.R., E-mail: holt@queensu.ca, E-mail: daymond@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

    2015-07-01

    The Reactor Materials Testing Laboratory (RMTL) at Queen's University and the results of commissioning tests are described. RMTL uses energetic protons (up to 8MeV) to simulate fast neutron damage in materials for reactor components. The laboratory is also capable of He implantation (up to 12 MeV) to simulate the effects of transmutation He in reactor components. The $17.5M laboratory comprises a new building, a 4MV tandem accelerator, two electron microscopes, mechanical testing and specimen preparation equipment, and a radiation detection laboratory. RMTL focusses on studying dynamic effects of irradiation (irradiation creep, irradiation growth, irradiation induced swelling, fatigue under irradiation) in-situ. (author)

  2. Cloning of the queen variety pineapple (Ananas comosus (L.) merr) through the callus

    International Nuclear Information System (INIS)

    Lapade, A.G.; Veluz, A.M.S.; Santos, I.S.

    1988-01-01

    Crown sections of pineapple were inoculated aseptically in Murashige and Skoog (MS) medium with varying levels of benzyl adenine (BA) in combination with napthalene acetic acid (NAA). Callus was induced from crown sections that was grown in MS with 0 ppm BA + 2 ppm NAA, 2 ppm BA + 6 ppm NAA. These calli when grown continuously in the same medium developed profusely into shoots. Callus and shoots developed profusely at medium containing 2 ppm BA + 2 ppm NAA. Calli that were further sub-cultured in MS with 2 ppm BA + 2 ppm NAA produced multiple shoots. Calli and shoots that were further sub-cultured in 0 to 4 ppm BA to 4 to 6 ppm NAA formed roots. Results showed that complete plantlets were produced from crown sections of pineapple variety Queen in MS medium supplemented with the different treatment combinations of BA and NAA. (Author). 9 refs.; 1 fig

  3. The escalatory Red Queen: Population extinction and replacement following arms race dynamics in poplar rust.

    Science.gov (United States)

    Persoons, Antoine; Hayden, Katherine J; Fabre, Bénédicte; Frey, Pascal; De Mita, Stéphane; Tellier, Aurélien; Halkett, Fabien

    2017-04-01

    Host-parasite systems provide convincing examples of Red Queen co-evolutionary dynamics. Yet, a key process underscored in Van Valen's theory - that arms race dynamics can result in extinction - has never been documented. One reason for this may be that most sampling designs lack the breadth needed to illuminate the rapid pace of adaptation by pathogen populations. In this study, we used a 25-year temporal sampling to decipher the demographic history of a plant pathogen: the poplar rust fungus, Melampsora larici-populina. A major adaptive event occurred in 1994 with the breakdown of R7 resistance carried by several poplar cultivars widely planted in Western Europe since 1982. The corresponding virulence rapidly spread in M. larici-populina populations and nearly reached fixation in northern France, even on susceptible hosts. Using both temporal records of virulence profiles and temporal population genetic data, our analyses revealed that (i) R7 resistance breakdown resulted in the emergence of a unique and homogeneous genetic group, the so-called cultivated population, which predominated in northern France for about 20 years, (ii) selection for Vir7 individuals brought with it multiple other virulence types via hitchhiking, resulting in an overall increase in the population-wide number of virulence types and (iii) - above all - the emergence of the cultivated population superseded the initial population which predominated at the same place before R7 resistance breakdown. Our temporal analysis illustrates how antagonistic co-evolution can lead to population extinction and replacement, hence providing direct evidence for the escalation process which is at the core of Red Queen dynamics. © 2016 John Wiley & Sons Ltd.

  4. Diversity Generator Mechanisms Are Essential Components of Biological Systems: The Two Queen Hypothesis.

    Science.gov (United States)

    Muraille, Eric

    2018-01-01

    Diversity is widely known to fuel adaptation and evolutionary processes and increase robustness at the population, species and ecosystem levels. The Neo-Darwinian paradigm proposes that the diversity of biological entities is the consequence of genetic changes arising spontaneously and randomly, without regard for their usefulness. However, a growing body of evidence demonstrates that the evolutionary process has shaped mechanisms, such as horizontal gene transfer mechanisms, meiosis and the adaptive immune system, which has resulted in the regulated generation of diversity among populations. Though their origins are unrelated, these diversity generator (DG) mechanisms share common functional properties. They (i) contribute to the great unpredictability of the composition and/or behavior of biological systems, (ii) favor robustness and collectivism among populations and (iii) operate mainly by manipulating the systems that control the interaction of living beings with their environment. The definition proposed here for DGs is based on these properties and can be used to identify them according to function. Interestingly, prokaryotic DGs appear to be mainly reactive, as they generate diversity in response to environmental stress. They are involved in the widely described Red Queen/arms race/Cairnsian dynamic. The emergence of multicellular organisms harboring K selection traits (longer reproductive life cycle and smaller population size) has led to the acquisition of a new class of DGs that act anticipatively to stress pressures and generate a distinct dynamic called the "White Queen" here. The existence of DGs leads to the view of evolution as a more "intelligent" and Lamarckian-like process. Their repeated selection during evolution could be a neglected example of convergent evolution and suggests that some parts of the evolutionary process are tightly constrained by ecological factors, such as the population size, the generation time and the intensity of

  5. Seismic potential of the Queen Charlotte-Alaska-Aleutian seismic zone

    Energy Technology Data Exchange (ETDEWEB)

    Nishenko, S.P. (Geological Survey, Denver, CO (United States)); Jacob, K.H. (Columbia Univ., Palisades, NY (United States))

    1990-03-10

    The 5,000 km long Queen Charlotte-Alaska-Aleutian seismic zone is subdivided into 17 unequally sized segments. The 17 segments are chosen to represent areas likely to be ruptured by characteristic earthquakes. This term usually implies repeated breakage of a plate boundary segment by either a large or great earthquake, whose source dimensions remain consistent from cycle to cycle. Formal computations of the conditional probabilities for future large and great earthquakes in the 17 segments of the Queen Charlotte-Alaska-Aleutian seismic zone are based on the following data sets and findings: (1) recurrence intervals from historic and geologic data; (2) direct recurrence time estimates based on rates of relative plate motion and the size or displacement of the most recent characteristic event in each segment; and (3) the application of a lognormal distribution of recurrence times for large and great earthquakes. Results of these computations indicate seven areas that have high (i.e., {ge} 60%) conditional probabilities for the recurrence of either large or great earthquakes within the next 20 years (1988-2008). These areas include Cape St. James, Yakataga, the Shumagin Islands, Unimak Island, and the Fox, Delarof, and Near Islands segments of the Aleutian arc. When a shorter time interval is considered (1988-1998), those segments more likely to rupture in large (M{sub S} 7-7.7) rather than great earthquakes have a high conditional probability. These areas include the Unimak, Fox, and Delarof Islands segments. The largest uncertainties in these forecasts stem from the short historic record (providing a single recurrence time estimate for some segments, or widely varying estimates for others); from the unknown importance of aseismic slip; and from a vague definition of characteristic earthquake size. In fact, characteristic earthquake size may not be a time-invariant quantity.

  6. Study of the seasonal variation in the exchanges of food labelled with 198Au from a worker bee to a queen (Apis mellifica ligustica S.)

    International Nuclear Information System (INIS)

    Pain, Janine; Roger, Bernard; Douault, Philippe

    1975-01-01

    Food exchanges from a worker giver to a queen receiver were quantified throughout the year. 4 days old workers distribute great amounts of food to queens, about 74% in average, but variations are low. On the other hand workers of unknown age distribute amounts that are less high and varying in terms of the season. A parallelism exists between percentage variations of food shared by workers of unknown age and the seasonal cycle of the 9-oxodec-2-enoic acid content of queens [fr

  7. Ao38, a new cell line from eggs of the black witch moth, Ascalapha odorata (Lepidoptera: Noctuidae, is permissive for AcMNPV infection and produces high levels of recombinant proteins

    Directory of Open Access Journals (Sweden)

    Zhang Sheng

    2010-07-01

    Full Text Available Abstract Background The insect cell line is a critical component in the production of recombinant proteins in the baculovirus expression system and new cell lines hold the promise of increasing both quantity and quality of protein production. Results Seventy cell lines were established by single-cell cloning from a primary culture of cells derived from eggs of the black witch moth (Ascalapha odorata; Lepidoptera, Noctuidae. Among 8 rapidly growing lines, cell line 38 (Ao38 was selected for further analysis, based on susceptibility to AcMNPV infection and production of secreted alkaline phosphatase (SEAP from a baculovirus expression vector. In comparisons with low-passage High Five (BTI-Tn-5B1-4 cells, infected Ao38 cells produced β-galactosidase and SEAP at levels higher (153% and 150%, respectively than those measured from High Five cells. Analysis of N-glycans of SEAP produced in Ao38 cells revealed two N-glycosylation sites and glycosylation patterns similar to those reported for High Five and Sf9 cells. Glycopeptide isoforms consisted of pauci- or oligomannose, with and without fucose on N-acetylglucosamine(s linked to asparagine residues. Estimates of Ao38 cell volume suggest that Ao38 cells are approximately 2.5× larger than Sf9 cells but only approximately 74% of the size of High Five cells. Ao38 cells were highly susceptible to AcMNPV infection, similar to infectivity of Sf9 cells. Production of infectious AcMNPV budded virions from Ao38 cells peaked at approximately 4.5 × 107 IU/ml, exceeding that from High Five cells while lower than that from Sf9 cells. Ao38 cells grew rapidly in stationary culture with a population doubling time of 20.2 hr, and Ao38 cells were readily adapted to serum-free medium (Sf-900III and to a suspension culture system. Analysis of Ao38 and a parental Ascalapha odorata cell line indicated that these lines were free of the alphanodavirus that was recently identified as an adventitious agent in High Five cell

  8. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair - degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  9. The Black Studies Boondoggle

    Science.gov (United States)

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  10. Black-Body Radiation

    Indian Academy of Sciences (India)

    Keywords. Black-body radiation; thermal radiation; heat; electromagnetic radiation; Stefan's Law; Stefan–Boltzmann Law; Wien's Law; Rayleigh–Jeans Law; black-body spectrum; ultraviolet catastrophe; zero point energy; photon.

  11. Dynamics of black holes

    OpenAIRE

    Hayward, Sean A.

    2008-01-01

    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping h...

  12. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.

    1976-01-01

    Recent work, which has been investigating the use of the concept of entropy with respect to gravitating systems, black holes and the universe as a whole, is discussed. The resulting theory of black holes assigns a finite temperature to them -about 10 -7 K for ordinary black holes of stellar mass -which is in complete agreement with thermodynamical concepts. It is also shown that black holes must continuously emit particles just like ordinary bodies which have a certain temperature. (U.K.)

  13. Monopole black hole skyrmions

    OpenAIRE

    Moss, I.G.; Shiiki, N.; Winstanley, E.

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  14. Alcoholism and Blacks.

    Science.gov (United States)

    Mosley, Bertha; And Others

    1988-01-01

    Notes that in America, knowledge base concerning alcoholism is concentrated on drinking patterns of Whites, and that Black Americans often differ in their drinking behavior, resulting in a need to clarify issues regarding alcoholism and Blacks. Provides theoretical information useful in better discerning drinking behavior of Blacks. (Author/NB)

  15. What is black hole?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is black hole? Possible end phase of a star: A star is a massive, luminous ball of plasma having continuous nuclear burning. Star exhausts nuclear fuel →. White Dwarf, Neutron Star, Black Hole. Black hole's gravitational field is so powerful that even ...

  16. Genocide and Black Ecology

    Science.gov (United States)

    Sinnette, Calvin H.

    1972-01-01

    Contends that the survival of black people is in serious jeopardy as is evidenced in contemporary discussions on the worldwide plight of black people, and that an exhaustive study of the problem in its many dimensions is seriously lacking; the moral and ethical issues of genocide require examination from a black perspective. (JW)

  17. Regulation of oogenesis in honey bee workers via programed cell death.

    Science.gov (United States)

    Ronai, Isobel; Barton, Deborah A; Oldroyd, Benjamin P; Vergoz, Vanina

    2015-10-01

    Reproductive division of labour characterises eusociality. Currently little is known about the mechanisms that underlie the 'sterility' of the worker caste, but queen pheromone plays a major role in regulating the reproductive state. Here we investigate oogenesis in the young adult honey bee worker ovary in the presence of queen pheromone and in its absence. When queen pheromone is absent, workers can activate their ovaries and have well-developed follicles. When queen pheromone is present, even though workers have non-activated ovaries, they continually produce oocytes which are aborted at an early stage. Therefore, irrespective of the presence of the queen, the young adult worker ovary contains oocytes. By this means young workers retain reproductive plasticity. The degeneration of the germ cells in the ovarioles of workers in the presence of queen pheromone has the morphological hallmarks of programmed cell death. Therefore the mechanistic basis of 'worker sterility' relies in part on the regulation of oogenesis via programmed cell death. Our results suggest that honey bees have co-opted a highly conserved checkpoint at mid-oogenesis to regulate the fertility of the worker caste. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  19. Black hole levitron

    International Nuclear Information System (INIS)

    Arsiwalla, Xerxes D.; Verlinde, Erik P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.'s multicenter supersymmetric black hole solutions provides a supergravity description of such backgrounds within which a black hole can be trapped within a confined volume. This construction is realized by solving for a levitating black hole over a magnetic dipole base. We comment on how such a construction is akin to a mechanical levitron.

  20. C-Glycosylated flavonoids from black gram husk: Protection against DNA and erythrocytes from oxidative damage and their cytotoxic effect on HeLa cells

    OpenAIRE

    T.K. Girish; K. Anil Kumar; U.J.S. Prasada Rao

    2016-01-01

    C-Glycosyl flavones are present in different plant tissues and they exhibit health benefits. In the present study, it was found that C-glycosyl flavones are distributed in different milled fractions of black gram and among these fractions, husk had the highest content of C-glycosyl flavones. Two C-glycosyl flavones from black gram husk were extracted and purified by preparative high-performance liquid chromatography (HPLC) column. The purity of each compound was assessed by analytical C18 col...

  1. Who was the Red Queen? Identity of the female Maya dignitary from the sarcophagus tomb of Temple XIII, Palenque, Mexico.

    Science.gov (United States)

    Tiesler, V; Cucina, A; Pacheco, A Romano

    2004-01-01

    The present investigation aims at contributing to the ongoing discussion on the unconfirmed identity of the Red Queen, a Classic Maya dignitary discovered in Temple XIII at Palenque, Mexico, by comparing her reconstructed facial profile to the portraiture of known female personages from the site. The comparison rests upon individual cranial features, like buccal prognatism, nasal root and inclination, chin prominence and the artificially shaped forehead. The similarities between the reconstruction, the female's funerary mask and local portraiture appear to identify the Red Queen as Lady Ix Tz'akb'u Ajaw (Ahpo Hel), the wife of Janaab' Pakal, one of the famous Maya rulers of the Classic Period. The proposed match and her family relationship with the king might explain the spatial closeness of their burial places in the Temple of the Inscriptions and Temple XIII.

  2. ‘A token of their love’: Queen Victoria Memorials in New Zealand

    Directory of Open Access Journals (Sweden)

    Mark Stocker

    2016-06-01

    Full Text Available This article provides an overview of the four metropolitan sculptural memorials to Queen Victoria in late-colonial New Zealand, which all immediately precede the colony’s Dominion status (1907. In chronological order, they were erected in Auckland, Christchurch, Wellington, and Dunedin. While the Auckland memorial was unveiled within the Queen’s lifetime, her death in 1901 catalysed the commission of more ambitious counterparts in Wellington and Dunedin, and a degree of intercity rivalry was consciously articulated in advocacy for them. The memorials reflect a Pākeha (European New Zealand sense of identity as a loyal, pro-monarchical, and imperial colony, but also as a ‘Better Britain’, with a proud sense of prosperity and achievement. Local content features prominently in two of them, notably the signing with Māori of the Treaty of Waitangi (1840 in one of the reliefs for the capital city memorial (Wellington, and an ambitious celebration of fifty years of provincial achievement in the pedestal sculpture for the Christchurch counterpart. Due to a dearth of home-grown talent, together with the belief in the artistic superiority of Britain (often known at the time as ‘Home’, British sculptors were invariably commissioned for these memorials. Cost-effectiveness, prestige, and the ability to render a realistic likeness were all criteria behind the choice of artists, with Francis John Williamson commissioned for two of them (Auckland and Christchurch. In researching this article, extensive use has been made of primary newspaper sources to document the political context of the memorials. In all of them, particularly that of Christchurch, New Zealand’s loyalty to Britain in the South African War (1899–1902 was a leading issue. Artistic and aesthetic issues and analysis were less prominent, although there was a widespread belief that the Queen should be honoured for purely symbolic and not utilitarian causes. While emphasis is given

  3. Seismic potential of the Queen Charlotte-Alaska-Aleutian Seismic Zone

    Science.gov (United States)

    Nishenko, S. P.; Jacob, K. H.

    1990-03-01

    The 5000 km long Queen Charlotte-Alaska-Aleutian seismic zone is subdivided into 17 unequally sized segments. Their boundaries are delineated based on the prior distribution of large and great earthquakes. The 17 segments are chosen to represent areas likely to be ruptured by "characteristic" earthquakes. This term usually implies repeated breakage of a plate boundary segment by either a large or great earthquake, whose source dimensions remain consistent from cycle to cycle. This definition does not exclude the possibility that occasionally adjacent characteristic earthquake segments may break together in a single "giant" event that is larger than the characteristic size outlined. Conversely, a segment can also sometimes break in a series of smaller ruptures. Formal computations of the conditional probabilities for future large and great earthquakes in the 17 segments of the Queen Charlotte-Alaska-Aleutian seismic zone are based on the following data sets and findings: (1) recurrence intervals from historic and geologic data; (2) direct recurrence time estimates based on rates of relative plate motion and the size or displacement of the most recent characteristic event in each segment; and (3) the application of a lognormal distribution of recurrence times for large and great earthquakes. Results of these computations indicate seven areas that have high (i.e., ≥60%) conditional probabilities for the recurrence of either large or great earthquakes within the next 20 years (1988-2008). These areas include Cape St. James, Yakataga, the Shumagin Islands, Unimak Island, and the Fox, Delarof, and Near Islands segments of the Aleutian arc. When a shorter time interval is considered (1988-1998), those segments more likely to rupture in large (MS 7-7.7) rather than great earthquakes have a high conditional probability. These areas include the Unimak, Fox, and Delarof Islands segments. The largest uncertainties in these forecasts stem from the short historic record

  4. Ultrafiltration and valorisation of lignin in black liquor from South African Kraft mills: A focus on dead-end stirred cell filtration

    CSIR Research Space (South Africa)

    Kekana, PT

    2014-07-01

    Full Text Available The main aim of this project is to develop a method that can effectively extract lignin from Kraft black liquors from South African mills in the form that would be suitable for valorisation into high value products. In this study the effects...

  5. MicroRNA signatures characterizing caste-independent ovarian activity in queen and worker honeybees (Apis mellifera L.).

    Science.gov (United States)

    Macedo, L M F; Nunes, F M F; Freitas, F C P; Pires, C V; Tanaka, E D; Martins, J R; Piulachs, M-D; Cristino, A S; Pinheiro, D G; Simões, Z L P

    2016-06-01

    Queen and worker honeybees differ profoundly in reproductive capacity. The queen of this complex society, with 200 highly active ovarioles in each ovary, is the fertile caste, whereas the workers have approximately 20 ovarioles as a result of receiving a different diet during larval development. In a regular queenright colony, the workers have inactive ovaries and do not reproduce. However, if the queen is sensed to be absent, some of the workers activate their ovaries, producing viable haploid eggs that develop into males. Here, a deep-sequenced ovary transcriptome library of reproductive workers was used as supporting data to assess the dynamic expression of the regulatory molecules and microRNAs (miRNAs) of reproductive and nonreproductive honeybee females. In this library, most of the differentially expressed miRNAs are related to ovary physiology or oogenesis. When we quantified the dynamic expression of 19 miRNAs in the active and inactive worker ovaries and compared their expression in the ovaries of virgin and mated queens, we noted that some miRNAs (miR-1, miR-31a, miR-13b, miR-125, let-7 RNA, miR-100, miR-276, miR-12, miR-263a, miR-306, miR-317, miR-92a and miR-9a) could be used to identify reproductive and nonreproductive statuses independent of caste. Furthermore, integrative gene networks suggested that some candidate miRNAs function in the process of ovary activation in worker bees. © 2016 The Royal Entomological Society.

  6. General and species-specific impacts of a neonicotinoid insecticide on the ovary development and feeding of wild bumblebee queens.

    Science.gov (United States)

    Baron, Gemma L; Raine, Nigel E; Brown, Mark J F

    2017-05-17

    Bumblebees are essential pollinators of crops and wild plants, but are in decline across the globe. Neonicotinoid pesticides have been implicated as a potential driver of these declines, but most of our evidence base comes from studies of a single species. There is an urgent need to understand whether such results can be generalized across a range of species. Here, we present results of a laboratory experiment testing the impacts of field-relevant doses (1.87-5.32 ppb) of the neonicotinoid thiamethoxam on spring-caught wild queens of four bumblebee species: Bombus terrestris , B. lucorum , B. pratorum and B. pascuorum. Two weeks of exposure to the higher concentration of thiamethoxam caused a reduction in feeding in two out of four species, suggesting species-specific anti-feedant, repellency or toxicity effects. The higher level of thiamethoxam exposure resulted in a reduction in the average length of terminal oocytes in queens of all four species. In addition to providing the first evidence for general effects of neonicotinoids on ovary development in multiple species of wild bumblebee queens, the discovery of species-specific effects on feeding has significant implications for current practices and policy for pesticide risk assessment and use. © 2017 The Authors.

  7. Congenital cranial ventral abdominal hernia, peritoneopericardial diaphragmatic hernia and sternal cleft in a 4-year-old multiparous pregnant queen

    Directory of Open Access Journals (Sweden)

    Camille Bismuth

    2017-12-01

    Full Text Available Case summary Cranial ventral midline hernias, most often congenital, can be associated with other congenital abnormalities, such as sternal, diaphragmatic or cardiac malformations. A 4-year-old multiparous queen with a substernal hernia was admitted for evaluation of a mammary mass. During CT examination, a bifid sternum, the abdominal hernia containing the intestines, spleen, omentum, three fetuses, a mammary mass and an incidental peritoneopericardial diaphragmatic hernia were identified. Surgery consisted of a standard ovariohysterectomy and repair of the peritoneopericardial hernia. Primary closure of the abdominal hernia was attempted but deemed impossible even after the ovariohysterectomy, splenectomy and a partial omentectomy. An external abdominal oblique muscle flap was used to close with no tension on the cranial part of the hernia. One month postoperatively, the queen had no respiratory abnormalities and the herniorrhaphy was fully healed. Relevance and novel information This case is the first description of a 4-year-old multiparous pregnant queen with complex congenital malformations and surgical correction of a peritoneopericardial hernia and a 6 × 8 cmsubsternal hernia with an external abdominal oblique muscle flap. Life-threatening sequelae associated with large abdominal hernias can be attributed to space-occupying effects known as loss of domain and compartment syndrome, which is why a muscle flap was used in this case. The sternal cleft was not repaired because of the size of the cleft and the age of the cat.

  8. Sex allocation conflict between queens and workers in Formica pratensis wood ants predicts seasonal sex ratio variation.

    Science.gov (United States)

    Helanterä, Heikki; Kulmuni, Jonna; Pamilo, Pekka

    2016-10-01

    Sex allocation theory predicts parents should adjust their investment in male and female offspring in a way that increases parental fitness. This has been shown in several species and selective contexts. Yet, seasonal sex ratio variation within species and its underlying causes are poorly understood. Here, we study sex allocation variation in the wood ant Formica pratensis. This species displays conflict over colony sex ratio as workers and queens prefer different investment in male and female offspring, owing to haplodiploidy and relatedness asymmetries. It is unique among Formica ants because it produces two separate sexual offspring cohorts per season. We predict sex ratios to be closer to queen optimum in the early cohort but more female-biased and closer to worker optimum in the later one. This is because the power of workers to manipulate colony sex ratio varies seasonally with the availability of diploid eggs. Consistently, more female-biased sex ratios in the later offspring cohort over a three-year sampling period from 93 colonies clearly support our prediction. The resulting seasonal alternation of sex ratios between queen and worker optima is a novel demonstration how understanding constraints of sex ratio adjustment increases our ability to predict sex ratio variation. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  9. Effects of cross-feeding anarchistic and wild type honey bees: anarchistic workers are not queen-like.

    Science.gov (United States)

    Beekman, Madeleine; Oldroyd, Benjamin P

    2003-04-01

    Unlike normal (wild type) honey bee ( Apis mellifera) colonies, 'anarchistic' colonies are characterised by workers that activate their ovaries in the presence of the queen and brood and by the ability of their workers to lay eggs that evade worker policing. In the Cape honey bee ( A. m. capensis), female larvae can manipulate non- capensis nurse workers such that they receive more larval food and develop into worker-queen intermediates or intercastes. We speculated that, in anarchistic colonies, larvae might produce signals that result in excessive feeding of female larvae. Excessively fed female larvae may then develop into reproductively active workers. In this study we cross-fostered anarchistic and wild type brood and investigated the effect of cross-fostering on the amount of food fed to larvae and on the morphology of the resulting workers. We show that anarchistic larvae do not manipulate wild type nurse workers into feeding them more, nor do anarchistic workers develop into worker-queen intermediates. On the contrary, anarchistic larvae are fed less than wild type larvae and anarchistic workers seem to be poor nurses in that they feed larvae less, irrespective of brood genotype.

  10. Lytton Strachey : l’historien intime de deux reines Lytton Strachey’s Intimate Biographies of Two Queens

    Directory of Open Access Journals (Sweden)

    Jeannine Hayat

    2007-01-01

    Full Text Available The British writer Lytton Strachey (1880-1932 wrote biographies of the two most eminent Queens of England: Queen Victoria (1921 and Elizabeth and Essex (1928. The two books made him a very famous historian. However, he would personally have preferred to be admired for his poetry or his plays, for he was a very gifted literary author. Nevertheless many of Strachey’s readers have appreciated his conception of biography, as a means of personal confession while studying the destiny of a public figure. Indeed the Stracheyan way of life, free from Victorian moral standards and guided by the rules of the Bloomsbury group, inspired his story of Victoria and Elizabeth. Both Queens at the end of their lives and at the height of their power carried on strange love affairs: Victoria with her Scottish gillie and Elizabeth with the Earl of Essex, thirty years her younger. In fact, both romances subtly reflect Strachey’s own love affairs. He was himself engaged in a kind of common life with Dora Carrington— the painter, thirteen years younger than him, with whom he was not sexually involved— while he engaged in numerous homosexual love affairs.

  11. Treatment of squamous cell and adenocarcinoma of the esophagus

    Directory of Open Access Journals (Sweden)

    Rathbone B

    2012-11-01

    Full Text Available Barrie Rathbone,1 Janusz Jankowski,2 Michael Rathbone31University Hospitals of Leicester, Leicester, 2Sir James Black Professor Queen Mary University of London, 3St George's University of London, London, United KingdomAbstract: Esophageal cancer is the sixth commonest cause of cancer death worldwide. It predominantly occurs in two histological types, ie, squamous cell carcinoma and adenocarcinoma, each with its own distinct geographical distribution and natural history. The incidence of esophageal adenocarcinoma is rising, as is that of its precursor lesion, Barrett's esophagus, which consists of metaplastic change in the squamous mucosa of the esophagus in response to damage by gastroesophageal reflux disease. The principal risk factors for esophageal cancer are cigarette smoking and alcohol consumption, reflux disease, and obesity. In tumors without local invasion or distant metastases, surgery remains the treatment option of choice, although there are considerable differences of opinion regarding the roles of chemotherapy and radiotherapy. A wide variety of endoscopic treatments are available for dysplastic lesions and palliation. Despite the availability of increasingly complex imaging modalities and expensive and possibly ineffective attempts at screening, the evidence base is conflicted and the prognosis remains poor. However, from a recent large systematic review, three clear recommendations can be made, ie, use of endoscopic resection for high grade dysplasia, use of radiofrequency ablation for residual premalignant lesions, and, finally, prevention of risk factors for cancer, such as smoking, alcohol consumption, and obesity.Keywords: cancer, Barrett's, esophagus, squamous cell carcinoma, adenocarcinoma

  12. Fetal-maternal conflict, trophoblast invasion, preeclampsia, and the red queen.

    Science.gov (United States)

    Pijnenborg, Robert; Vercruysse, Lisbeth; Hanssens, Myriam

    2008-01-01

    The much publicized conflict hypothesis for understanding fetal-maternal interaction during pregnancy often invokes a 'battle' metaphor, rather than a well orchestrated interplay occurring as a series of well controlled moves and counter-moves as happens in a game of chess. Such stepwise interaction is particularly obvious in the spiral artery remodelling process, and it would be interesting to trace the history of the successive steps in histological adaptation throughout primate phylogeny. The restricted invasion observed in a few species on a 'lower' evolutionary scale suggests a tendency of progressive deeper invasion during primate evolution. Unfortunately, our knowledge of invasive processes in the placental bed in nonhuman primates is highly inadequate. A paradigm underscoring the stepwise interaction between mother and fetus may be provided by the Red Queen hypothesis, which is a useful model to explain co-evolutionary processes between different species. The apparent association between preeclampsia and restricted endovascular trophoblast invasion, combined with the absence of the disease in primate species showing shallow invasion, suggests that preeclampsia may result from a failure in one or more interactive steps necessary for deeper invasion. Evidence for a genetic component invokes the puzzling question as to why "preeclampsia genes" are not eliminated from human populations. As in other fields of medicine, a proper understanding of Darwinian selection processes may throw some light on the causes of preeclampsia.

  13. Do the HIV-1 subtypes circulating in Italy resemble the Red Queen running in Carroll's novel?

    Science.gov (United States)

    Ciccozzi, Massimo; Bon, Isabella; Ciotti, Marco

    2010-04-01

    The human immunodeficiency virus type 1 (HIV-1) pandemic is currently in its third decade and approximately 35 million people are infected worldwide. HIV-1 genetic variability results in 9 phylogenetic subtypes and several circulating recombinant forms (CRFs). In Italy, the first phase of the HIV epidemic was mainly confined to the intravenous drug users (IDU) risk group, moreover most studies have focused on different aspects of the non B subtype such as drugs and therapeutic protocols, laboratory methodologies (heteroduplex mobility assay, PCR screening methods) for the identification of phenotypic variants. These studies were mostly locally conducted. In this context, the Red Queen Hypothesis might be suggestive. In the first original expression that comes from Chapter 2, Through the Looking Glass. To improve our knowledge, in the near future, we will need to investigate the demographic and spatiotemporal history of different HIV-1 subtypes circulating in Italy in a large data set of sequences, involving a sample size comparable with the Italian population. To monitor the genetic evolution of the HIV-1 in a large data-set represent an essential strategy to control the local as well as the global HIV-1 epidemic and to develop efficient preventive and therapeutic strategies, with a great impact in clinical practice.

  14. Mode of transmission, host switching, and escape from the Red Queen by viviparous gyrodactylids (Monogenoidea).

    Science.gov (United States)

    Boeger, Walter A; Kritsky, Delane C; Pie, Marcio R; Engers, Kerlen B

    2005-10-01

    Compared to other monogenoidean groups, viviparous gyrodactylids exhibit extraordinary species diversity and broad host range. It has been suggested that this evolutionary success is associated with a suite of morphological and life-history traits that include, in part, continuous transmission (i.e., ability to infect new hosts throughout the gyrodactylid life cycle). Experiments were conducted to explore the putative adaptive advantage of continuous transmission within viviparous gyrodactylids during colonization of new host resources. Differences in infrapopulation growth, such as abundance, prevalence, and duration of the infection, of Gyrodactylus anisopharynx on 3 species of fish--Corydoras paleatus and Corydoras ehrhardti (both natural hosts) as well as Corydoras schwartzi (a host not known to harbor G. anisopharynx)--held under isolated and grouped conditions were determined. Results showed that infrapopulations of G. anisopharynx on C. paleatus and C. schwartzi had higher growth when the parasite had the opportunity for host transfer (grouped hosts). Infrapopulations of G. anisopharynx on isolated and grouped C. ehrhardti showed an opposite trend, although differences in mean duration and maximum abundance were not statistically different. Results obtained from experiments with C. paleatus and C. schwartzi support the hypothesis that continuous transmission in viviparous gyrodactylids enhances colonization success, probably by allowing initial avoidance of Red Queen dynamics. The absence of statistical differences between infrapopulations on isolated and grouped C. ehrhardti suggests that parasite dynamics may be influenced by factors other than continuous transmission in this host.

  15. The Red Queen and her king: cooperation at all levels of life.

    Science.gov (United States)

    Weiss, Kenneth M; Buchanan, Anne V; Lambert, Brian W

    2011-01-01

    The Red Queen in "Through the Looking Glass" is often used as a metaphor for the relentless, unremitting competitive struggle by which Darwin described life. That imagery fits comfortably in our culture, with its emphasis on competition and inequity, but less so for nature herself. Life is manifestly much more about cooperation, at all levels and through a variety of ubiquitous mechanisms, than it is about competition. Most organisms of most species are nowhere near the proverbial Malthusian edge of survival, such that selection will detect the tiniest difference in their performance and enhance its genetic basis. Cooperation through interaction of multiple entities is inherent in many fundamental aspects of life, and its importance is not widely enough appreciated. Here we discuss a set of principles by which this works. We illustrate the points with a computer simulation of a topic of interest to anthropology, the development of the head. In a sense, our culture has its metaphors reversed. The red royal family is a more accurate symbol for the true nature of life, human or otherwise. Copyright © 2011 Wiley Periodicals, Inc.

  16. Infection dynamics in coexisting sexual and asexual host populations: support for the Red Queen hypothesis.

    Science.gov (United States)

    Vergara, Daniela; Jokela, Jukka; Lively, Curtis M

    2014-08-01

    The persistence of sexual reproduction is a classic problem in evolutionary biology. The problem stems from the fact that, all else equal, asexual lineages should rapidly replace coexisting sexual individuals due to the cost of producing males in sexual populations. One possible countervailing advantage to sexual reproduction is that, on average, outcrossed offspring are more resistant than common clones to coevolving parasites, as predicted under the Red Queen hypothesis. In this study, we evaluated the prevalence of infection by a sterilizing trematode (Microphallus sp.) in a natural population of freshwater snails that was composed of both sexual and asexual individuals (Potamopyrgus antipodarum). More specifically, we compared the frequency of infection in sexual and asexual individuals over a 5-year period at four sites at a natural glacial lake (Lake Alexandrina, South Island, New Zealand). We found that at most sites and over most years, the sexual population was less infected than the coexisting asexual population. Moreover, the frequency of uninfected sexual females was periodically greater than two times the frequency of uninfected asexual females. These results give clear support for a fluctuating parasite-mediated advantage to sexual reproduction in a natural population.

  17. The role of biotic forces in driving macroevolution: beyond the Red Queen.

    Science.gov (United States)

    Voje, Kjetil L; Holen, Øistein H; Liow, Lee Hsiang; Stenseth, Nils Chr

    2015-06-07

    A multitude of hypotheses claim that abiotic factors are the main drivers of macroevolutionary change. By contrast, Van Valen's Red Queen hypothesis is often put forward as the sole representative of the view that biotic forcing is the main evolutionary driver. This imbalance of hypotheses does not reflect our current knowledge: theoretical work demonstrates the plausibility of biotically driven long-term evolution, whereas empirical work suggests a central role for biotic forcing in macroevolution. We call for a more pluralistic view of how biotic forces may drive long-term evolution that is compatible with both phenotypic stasis in the fossil record and with non-constant extinction rates. Promising avenues of research include contrasting predictions from relevant theories within ecology and macroevolution, as well as embracing both abiotic and biotic proxies while modelling long-term evolutionary data. By fitting models describing hypotheses of biotically driven macroevolution to data, we could dissect their predictions and transcend beyond pattern description, possibly narrowing the divide between our current understanding of micro- and macroevolution. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  18. Damped long-term host-parasite Red Queen coevolutionary dynamics: a reflection of dilution effects?

    Science.gov (United States)

    Decaestecker, Ellen; De Gersem, Herbert; Michalakis, Yannis; Raeymaekers, Joost A M

    2013-12-01

    An increase in biological diversity leads to a greater stability of ecosystem properties. For host-parasite interactions, this is illustrated by the 'dilution effect': a negative correlation between host biodiversity and disease risk. We show that a similar mechanism might stabilise host-parasite dynamics at a lower level of diversity, i.e. at the level of genetic diversity within host species. A long-term time shift experiment, based on a historical reconstruction of a Daphnia-parasite coevolution, reveals infectivity cycles with more stable amplitude in experienced than in naive hosts. Coevolutionary models incorporating an increase in host allelic diversity over time explain the detected asymmetry. The accumulation of resistance alleles creates an opportunity for the host to stabilise Red Queen dynamics. It leads to a larger arsenal enhancing the host performance in its coevolution with the parasite in which 'it takes all the running both antagonists can do to keep in the same place'. © 2013 John Wiley & Sons Ltd/CNRS.

  19. Domestic queens under natural temperate photoperiod do not manifest seasonal anestrus.

    Science.gov (United States)

    Faya, M; Carranza, A; Priotto, M; Abeya, M; Diaz, J D; Gobello, C

    2011-11-01

    Domestic cat seasonality between the tropics and the arctic zones is scarcely described and results are inconsistent. The aim of this study was to describe domestic feline seasonal patterns under a natural temperate photoperiod. A total of 372 estrous cycles were studied in 34 post pubertal cats during 900 days. The queens were housed in a cat colony (31°25' South Latitude, 64°11' West Longitude), acclimated under natural photoperiod and daily observed for reproductive behavior. Vaginal cytology was conducted three times a week. For each cat the number of estrous cycles and days in estrus per month for each year were recorded. The months of the year were grouped in four periods of 3 months each according to day length and photoperiod. Comparisons of estrous days among periods were performed by ANOVA for repeated measures. All the cats had estrous cycles throughout the year without intervals of anestrus. Mean number of estrous days differed among the periods (Pphotoperiod being greater (12.5±0.6) to those of descending photoperiod either with long (8.9±0.7) or short (9.3±0.7) days. When the two periods with ascending day lengths were merged and compared to the two periods with descending day lengths merged, the number of estrous days were greater when day length ascended (Pphotoperiod have estrous cycles throughout the year showing peak activity the months with increasing photoperiod. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Eco-evolutionary feedback promotes Red Queen dynamics and selects for sex in predator populations.

    Science.gov (United States)

    Haafke, Julia; Abou Chakra, Maria; Becks, Lutz

    2016-03-01

    Although numerous hypotheses exist to explain the overwhelming presence of sexual reproduction across the tree of life, we still cannot explain its prevalence when considering all inherent costs involved. The Red Queen hypothesis states that sex is maintained because it can create novel genotypes with a selective advantage. This occurs when the interactions between species induce frequent environmental change. Here, we investigate whether coevolution and eco-evolutionary feedback dynamics in a predator-prey system allows for indirect selection and maintenance of sexual reproduction in the predator. Combining models and chemostat experiments of a rotifer-algae system we show a continuous feedback between population and trait change along with recurrent shifts from selection by predation and competition for a limited resource. We found that a high propensity for sex was indirectly selected and was maintained in rotifer populations within environments containing these eco-evolutionary dynamics; whereas within environments under constant conditions, predators evolved rapidly to lower levels of sex. Thus, our results indicate that the influence of eco-evolutionary feedback dynamics on the overall evolutionary change has been underestimated. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  1. Late Miocene mollusks from the Queen Charlotte Islands, British Columbia, Canada

    Science.gov (United States)

    Addicott, Warren O.

    1978-01-01

    A fauna of bivalve mollusks, scattered gastropods, and an echinoid from exposures of the Skonun Formation in the northeastern part of Graham Island is indicative of an early late Miocene age and correlation with the provincial Wishkahan Stage. The molluscan assemblages are from the upper 600 of the 1800-m-thick marine and nonmarine formation, which appears to be entirely of late Miocene age. The Skonun Formation is the strandline fa.cies of marginal marine and nonmarine deposits of the northwestern part of the Queen Charlotte basin, a Nieogene embayment paralleling the modern mainland coast. The molluscan fauna and associated lignite beds are known from a few widely scattered outcrops; they are indicative of alternating marine and nonmarine to brackish-water environments in the upper part of the formation. The Skonun fauna occurs near the northern boundary of the Pacific Northwest Neogene molluscan province. It is the only marine Neogene molluscan fauna known from the British Columbia coast. The fauna has strong taxonomic ties with the fauna of the Empire Formation of southwestern Oregon and has several species in common with the upper Miocene of the Lituya district, southeastern Alaska, implying that these three faunas are coeval.

  2. Adopting a blended approach to learning: Experiences from Radiography at Queen Margaret University, Edinburgh

    Energy Technology Data Exchange (ETDEWEB)

    Cockbain, M.M. [Radiography, School of Health Sciences, Queen Margaret University, Queen Margaret University Drive, Musselburgh, Edinburgh EH21 6UU (United Kingdom)], E-mail: mcockbain@qmu.ac.uk; Blyth, C.M. [Radiography, School of Health Sciences, Queen Margaret University, Queen Margaret University Drive, Musselburgh, Edinburgh EH21 6UU (United Kingdom); Bovill, C. [Edinburgh and Teaching and Learning Service, University of Glasgow, Glasgow (United Kingdom); Morss, K. [Centre for Academic Practice, Queen Margaret University (United Kingdom)

    2009-08-15

    The perspective of the radiography teaching team at Queen Margaret University (QMU) was that a transmission mode of programme delivery was sub-optimal in helping students to learn and make links between theory and practice. Programme redesign adopted a blended learning approach with both face-to-face and online learning aimed at enhancing the students' control over their own learning. Online tasks within Web Classroom Tools (WebCT) were used as an integral part of careful programme design, which resulted in a programme enabling synthesis of the skills, knowledge and competencies acquired in the academic and clinical environments. With the move towards a more learner-centred, blended educational experience for the students the lecturers' role shifted to that of facilitator with WebCT providing the tutor with a more transparent view of student learning. Lecturers plan learning activities that build upon the skills students have developed through learning in groups, online and in class. The explicit connections that now exist between the academic programme and the opportunities for applying knowledge in practice allow students to engage more deeply in their learning.

  3. Perspectives of patients towards medical students' at the Queen Elizabeth Central Hospital, Blantyre, Malawi.

    Science.gov (United States)

    Molapo, M; Muula, A S

    2010-01-01

    Medical students gaining experience in outpatient's clinics and admission wards are exposed to clinical clerkship as this is an important part of their training. There is paucity of reported patients' experiences and perceptions of medical students in low-income settings. The present study was conducted at the Queen Elizabeth Central Hospital (QECH), Malawi to describe patients' and perceptions of, and experience with medical students being present when patients are seen by a medical doctor or students' individual clerking. Participants mostly felt that medical students were compassionate, enthusiastic and helpful to them. The participants' who had been ever clerked by students felt motivated to be present for student learning for altruistic reasons as well as for mutual benefit between student and patient. Patients attending the QECH in Blantyre, Malawi are generally satisfied with the attention and support they obtain from students. Balancing the need for appropriate supervision of students, and facilitating the retention of this patient-cantered approach to care should be maintained.

  4. Experimental Study on Boiling Regime During Quenching Process in Heated Rod Bundle Queen

    International Nuclear Information System (INIS)

    J, Mulya; Antariksawan, A.R.; PW, Joko; S, Edy; H, Khairul; H, Ismu; Kiswanta; Giarno

    2003-01-01

    Following loss-of-coolant accident in light water reactor, the emergency core cooling must be injected. During flooding the core, the fuel cladding quenching occurred. The fuel quenching velocity is key factor for reactor safety. Various parameter influence the quenching velocity. It can also be related to the boiling regime change during transient. Current experimental study is performed to observe and apprehend boiling regime during quenching process and to measure its velocity. Experiment is conducted using Queen heated rod bundle. The quenching occurred from bottom flooding with flow rate of 0.0417 kg/s. The initial temperature of heated rod varies from 334 o C at zero point and 499 o C at top of heated zone. The visual observation method and rod surface temperature measurements is used to discus the change of boiling regime and quench front velocity. From the observation, it is obvious that at a one defined point, the boiling regime change from film boiling to single phase convection. On the other hand, the quench front velocity was affected by surface temperature and boiling regime. At the heated zone and at the beginning of quench, the quench front velocity was relatively low. While the surface temperature decreases, the quench front velocity was increase until all vapor film collapse. The average quench front velocity is about 11.5 mm/s

  5. Theology: Still a queen of science in the post-modern era

    Directory of Open Access Journals (Sweden)

    Erna Oliver

    2016-08-01

    Full Text Available Theology is just as relevant today as it was in the time of Aquinas who called theology ‘the queen of science’ although the knowledge-driven network society does not seem to be in agreement. By using the tools provided by the fourth revolution in the development of society, theology can, as part of the academic world of higher education that is supposed to lead society, strengthen ties with the past, seek explanations and solutions to current problems and produce guidelines for future investigation through multi- and interdisciplinary discourse. Theology can and should influence people to become positive change agents, re-shape the way in which the message of salvation is brought to the world in order to stay relevant in changing circumstances and be on the forefront of progressive transformation in society. This should be achieved through constant dialogue with other academic disciplines, the Church as institution and with society in general.

  6. Sulimar Queen environmental restoration project closure package Sandia environmental stewardship exemplar.

    Energy Technology Data Exchange (ETDEWEB)

    Tillman, Jack B.

    2008-09-01

    In March 2008, Sandia National Laboratories (Sandia), in partnership with the Bureau of Land Management, Roswell Field Office, completed its responsibilities to plug and abandon wells and restore the surface conditions for the Sulimar Queens Unit, a 2,500 acre oil field, in Chaves County, Southeast New Mexico. Sandia assumed this liability in an agreement to obtain property to create a field laboratory to perform extensive testing and experimentation on enhanced oil recovery techniques for shallow oil fields. In addition to plugging and abandoning 28 wells, the project included the removal of surface structures and surface reclamation of disturbed lands associated with all plugged and abandoned wells, access roads, and other auxiliary facilities within unit boundaries. A contracting strategy was implemented to mitigate risk and reduce cost. As the unit is an important wildlife habitat for prairie chickens, sand dune lizards, and mule deer, the criteria for the restoration and construction process were designed to protect and enhance the wildlife habitat. Lessons learned from this project include: (1) extreme caution should be exercised when entering agreements that include future liabilities, (2) partnering with the regulator has huge benefits, and (3) working with industry experts, who were familiar with the work, and subcontractors, who provided the network to complete the project cost effectively.

  7. How counterfactuals of Red-Queen theory shed light on science and its historiography.

    Science.gov (United States)

    Dagg, Joachim L

    2017-08-01

    A historical episode of evolutionary theory, which has lead to the Red Queen theory of the evolutionary maintenance of sex, includes two striking contingencies. These are used to explore alternative what-if scenarios, in order to test some common opinions about such counterfactuals. This sheds new light on the nature of science and its historiography. One counterfactual leads to an unexpected convergence of its result to that of the actual science but, nevertheless, differs in its causal structure. The other diverges towards an incompatible alternative, but this requires further contingent choices that also diverge from actual science. The convergence in the first counterfactual is due to a horizontal transfer of knowledge. Similar transfers of knowledge are typical for innovations of actual science. This suggests that contingent choices can merge as well as fork research traditions both in actual research and counterfactual history. Neither the paths of the actual history of science nor those of its counterfactual alternatives will form a tree of exclusively diverging bifurcations, but a network instead. Convergencies in counterfactuals may, therefore, be due to the web-structure of science as much as to the aims of the historians in question. Furthermore, the difference in causal structure between the actual science and its convergent counterfactual might become diagnostic for external factors rather than internal aims forcing a historian towards convergence. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Adopting a blended approach to learning: Experiences from Radiography at Queen Margaret University, Edinburgh

    International Nuclear Information System (INIS)

    Cockbain, M.M.; Blyth, C.M.; Bovill, C.; Morss, K.

    2009-01-01

    The perspective of the radiography teaching team at Queen Margaret University (QMU) was that a transmission mode of programme delivery was sub-optimal in helping students to learn and make links between theory and practice. Programme redesign adopted a blended learning approach with both face-to-face and online learning aimed at enhancing the students' control over their own learning. Online tasks within Web Classroom Tools (WebCT) were used as an integral part of careful programme design, which resulted in a programme enabling synthesis of the skills, knowledge and competencies acquired in the academic and clinical environments. With the move towards a more learner-centred, blended educational experience for the students the lecturers' role shifted to that of facilitator with WebCT providing the tutor with a more transparent view of student learning. Lecturers plan learning activities that build upon the skills students have developed through learning in groups, online and in class. The explicit connections that now exist between the academic programme and the opportunities for applying knowledge in practice allow students to engage more deeply in their learning.

  9. The role of biotic forces in driving macroevolution: beyond the Red Queen

    Science.gov (United States)

    Voje, Kjetil L.; Holen, Øistein H.; Liow, Lee Hsiang; Stenseth, Nils Chr.

    2015-01-01

    A multitude of hypotheses claim that abiotic factors are the main drivers of macroevolutionary change. By contrast, Van Valen's Red Queen hypothesis is often put forward as the sole representative of the view that biotic forcing is the main evolutionary driver. This imbalance of hypotheses does not reflect our current knowledge: theoretical work demonstrates the plausibility of biotically driven long-term evolution, whereas empirical work suggests a central role for biotic forcing in macroevolution. We call for a more pluralistic view of how biotic forces may drive long-term evolution that is compatible with both phenotypic stasis in the fossil record and with non-constant extinction rates. Promising avenues of research include contrasting predictions from relevant theories within ecology and macroevolution, as well as embracing both abiotic and biotic proxies while modelling long-term evolutionary data. By fitting models describing hypotheses of biotically driven macroevolution to data, we could dissect their predictions and transcend beyond pattern description, possibly narrowing the divide between our current understanding of micro- and macroevolution. PMID:25948685

  10. The Big Rust and the Red Queen: Long-Term Perspectives on Coffee Rust Research.

    Science.gov (United States)

    McCook, Stuart; Vandermeer, John

    2015-09-01

    Since 2008, there has been a cluster of outbreaks of the coffee rust (Hemileia vastatrix) across the coffee-growing regions of the Americas, which have been collectively described as the Big Rust. These outbreaks have caused significant hardship to coffee producers and laborers. This essay situates the Big Rust in a broader historical context. Over the past two centuries, coffee farmers have had to deal with the "curse of the Red Queen"-the need to constantly innovate in the face of an increasing range of threats, which includes the rust. Over the 20th century, particularly after World War II, national governments and international organizations developed a network of national, regional, and international coffee research institutions. These public institutions played a vital role in helping coffee farmers manage the rust. Coffee farmers have pursued four major strategies for managing the rust: bioprospecting for resistant coffee plants, breeding resistant coffee plants, chemical control, and agroecological control. Currently, the main challenge for researchers is to develop rust control strategies that are both ecologically and economically viable for coffee farmers, in the context of a volatile, deregulated coffee industry and the emergent challenges of climate change.

  11. Recreations in the theory of numbers the queen of mathematics entertains

    CERN Document Server

    Beiler, Albert H

    1966-01-01

    Number theory, the Queen of Mathematics, is an almost purely theoretical science. Yet it can be the source of endlessly intriguing puzzle problems, as this remarkable book demonstrates. This is the first book to deal exclusively with the recreational aspects of the subject and it is certain to be a delightful surprise to all devotees of the mathematical puzzle, from the rawest beginner to the most practiced expert. Almost every aspect of the theory of numbers that could conceivably be of interest to the layman is dealt with, all from the recreational point of view. Readers will become acquainted with divisors, perfect numbers, the ingenious invention of congruences by Gauss, scales of notation, endless decimals, Pythagorean triangles (there is a list of the first 100 with consecutive legs; the 100th has a leg of 77 digits), oddities about squares, methods of factoring, mysteries of prime numbers, Gauss's Golden Theorem, polygonal and pyramidal numbers, the Pell Equation, the unsolved Last Theorem of Fermat, a...

  12. Matilda, Edgith and Adelaide: conflicts between generations and the doweries of the queens in Germany

    Directory of Open Access Journals (Sweden)

    Giovanni Isabella

    2012-10-01

    Full Text Available The reconstruction of the size and geographical distribution of properties that made up the dowers of the first three Ottonian queens makes possible to see the great importance of these assets, both for their large extension, both for the relevant strategic role dues to their location. Already Henry I, the first king of the dynasty, endowed his wife Matilda with numerous curtes that belonged to the area of oldest and strong presence of the Ottonian family, namely the eastern Saxony and Thuringia. Precisely, the control of these important goods was the cause of the fight between Matilda and her son Otto I when, in 938, the mother supported the claims to the throne of her younger son Henry during a revolt against Otto. The dower of Edgith, the first wife of Otto, was made from the large curtis of Magdeburg, which became a place of great symbolic and political importance thanks to the burial of the royal couple and for its elevation to Archdiocese which was entrusted with the supervision of slavic territories east of the Elbe. The set of the assets granted in Germany by Otto to Adelaide, his second wife, it's difficult to reconstruct in detail, but it was definitely of great extent in continuity with the dower of Matilda, although compared to this the curtes were spread across a wider area encompassing both the eastern Saxony and Thuringia, both Alsace and Franconia.

  13. The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa

    International Nuclear Information System (INIS)

    Chattopadhyay, Koushik; Williamson, Anna-Lise; Hazra, Annapurna; Dandara, Collet

    2015-01-01

    Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (−1377G > A and -670A > G), FasL (−844 T > C) and CASP8 (−652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins. In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection. Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2. CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = −2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = −2.28) of HSV-2 infection in both black African and mixed-ancestry population. Our results show that the combined risks of variants in cell death pathway genes

  14. The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa.

    Science.gov (United States)

    Chattopadhyay, Koushik; Williamson, Anna-Lise; Hazra, Annapurna; Dandara, Collet

    2015-10-12

    Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (-1377G > A and -670A > G), FasL (-844 T > C) and CASP8 (-652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins. In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection. Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2. CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = -2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = -2.28) of HSV-2 infection in both black African and mixed-ancestry population. Our results show that the combined risks of

  15. Interacting black holes

    International Nuclear Information System (INIS)

    Costa, Miguel S.; Perry, Malcolm J.

    2000-01-01

    We revisit the geometry representing l collinear Schwarzschild black holes. It is seen that the black holes' horizons are deformed by their mutual gravitational attraction. The geometry has a string like conical singularity that connects the holes but has nevertheless a well defined action. Using standard gravitational thermodynamics techniques we determine the free energy for two black holes at fixed temperature and distance, their entropy and mutual force. When the black holes are far apart the results agree with Newtonian gravity expectations. This analyses is generalized to the case of charged black holes. Then we consider black holes embedded in string/M-theory as bound states of branes. Using the effective string description of these bound states and for large separation we reproduce exactly the semi-classical result for the entropy, including the correction associated with the interaction between the holes

  16. Black silicon integrated aperture

    Science.gov (United States)

    Liu, Tianbo; Dickensheets, David L.

    2017-10-01

    This paper describes the incorporation of nanotextured black silicon as an optical absorbing material into silicon-based micro-optoelectromechanical systems devices to reduce stray light and increase optical contrast during imaging. Black silicon is created through a maskless dry etch process and characterized for two different etch conditions, a cold etch performed at 0°C and a cryogenic etch performed at -110°C. We measure specular reflection at visible wavelengths to be black velvet paint used to coat optical baffles and compare favorably with other methods to produce black surfaces from nanotextured silicon or using carbon nanotubes. We illustrate the use of this material by integrating a black silicon aperture around the perimeter of a deformable focus-control mirror. Imaging results show a significant improvement in contrast and image fidelity due to the effective reduction in stray light achieved with the self-aligned black aperture.

  17. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  18. Black branes as piezoelectrics.

    Science.gov (United States)

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  19. Naked black holes

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Ross, S.F.

    1997-01-01

    It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. copyright 1997 The American Physical Society

  20. Nonextremal stringy black hole

    International Nuclear Information System (INIS)

    Suzuki, K.

    1997-01-01

    We construct a four-dimensional BPS saturated heterotic string solution from the Taub-NUT solution. It is a nonextremal black hole solution since its Euler number is nonzero. We evaluate its black hole entropy semiclassically. We discuss the relation between the black hole entropy and the degeneracy of string states. The entropy of our string solution can be understood as the microscopic entropy which counts the elementary string states without any complications. copyright 1997 The American Physical Society