WorldWideScience

Sample records for rein kuusik ants

  1. Rägavere mõisahoone restaureerimine / Toomas Rank, Rein Mõtus, Ants Hein

    Index Scriptorium Estoniae

    Rank, Toomas

    2005-01-01

    2 välis- ja 5 sisevaadet, joonis; uuringud: Ants Hein; projekt, muinsuskaitseline järelevalve: Toomas Rank; teostus: AS Sado Ehitus; sepised: Rein Mõtus; T. Rank pälvis Rägavere mõisa peahoone restaureerimise eest Eesti Kultuurkapitali 2004. a. aastapreemia

  2. Rägavere mõisahoone restaureerimine / Toomas Rank, Rein Mõtus, Ants Hein

    Index Scriptorium Estoniae

    Rank, Toomas

    2005-01-01

    2 välis- ja 5 sisevaadet, joonis; uuringud: Ants Hein; projekt, muinsuskaitseline järelevalve: Toomas Rank; teostus: AS Sado Ehitus; sepised: Rein Mõtus; T. Rank pälvis Rägavere mõisa peahoone restaureerimise eest Eesti Kultuurkapitali 2004. a. aastapreemia

  3. ANT

    DEFF Research Database (Denmark)

    van der Duim, René; Ren, Carina Bregnholm; Jóhannesson, Gunnar Thór

    2017-01-01

    Ten years ago actor-network theory (ANT) entered this journal. To illustrate how the relational ontology and sensibilities of ANT lend themselves to particular kinds of research, we first interrogate the main controversies as a way to open up and discuss the main premises of ANT. These debates...... concern the status and agency of objects and non-humans, ANT’s denial of the explanatory power of social structures, and the political implications of ANT. Second we present ANT’s relevance for tourism studies and discuss what ANT ‘does’ in practice. After summarizing a decade of relations between ANT...... and tourism, we conclude by tracing three future trajectories of how we have ‘moved away with’ ANT into new areas of discovery....

  4. Rein tension during canter

    NARCIS (Netherlands)

    Egenvall, Agneta; Eisersiö, Marie; Rhodin, Marie; van Weeren, P.R.; Roepstorff, Lars

    2015-01-01

    Riders generally use reins as a means for communication with the horse. At present, the signalling pattern is poorly understood. The aim of this study was to illustrate and analyse the rein tension patterns in a number of rider/horse combinations across a variety of exercises in the canter gait. Our

  5. Kapital annab Rein Kilgile loominguvabaduse / Nils Niitra

    Index Scriptorium Estoniae

    Niitra, Nils, 1975-

    2004-01-01

    Rein Kilgil on 28 ettevõtet, see võimaldab rakendada ettevõtluses loomingulisust. Vt. samas: Priit Rajalo. Rein Kilk hämmastab oskusega ajast kõik võtta. Lisa: Rein Kilgi enamusosalusega ettevõtted; Rein Kilk on tööandja ligi 1000 inimesele; Rein Kilgi enamusosaluseta ettevõtted; Rein Kilgiga on seotud veel

  6. Kapital annab Rein Kilgile loominguvabaduse / Nils Niitra

    Index Scriptorium Estoniae

    Niitra, Nils, 1975-

    2004-01-01

    Rein Kilgil on 28 ettevõtet, see võimaldab rakendada ettevõtluses loomingulisust. Vt. samas: Priit Rajalo. Rein Kilk hämmastab oskusega ajast kõik võtta. Lisa: Rein Kilgi enamusosalusega ettevõtted; Rein Kilk on tööandja ligi 1000 inimesele; Rein Kilgi enamusosaluseta ettevõtted; Rein Kilgiga on seotud veel

  7. Rein Veidemann elab vana kodulinna provintslusilminguid valusalt läbi / Rein Veidemann ; interv. Rein Hallik

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2007-01-01

    Pärnust pärit kirjanik-poliitik Rein Veidemann meenutab lapsepõlve, kooliaega, laulvat revolutsiooni. Vt. samas: Rein Veidemann; Kuidas Veidemann okupandiks sattus; Veidemann tegi koos Ojakääruga Rääma kooli hümni; Rein Kask. Meenutus

  8. Rein Veidemann elab vana kodulinna provintslusilminguid valusalt läbi / Rein Veidemann ; interv. Rein Hallik

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2007-01-01

    Pärnust pärit kirjanik-poliitik Rein Veidemann meenutab lapsepõlve, kooliaega, laulvat revolutsiooni. Vt. samas: Rein Veidemann; Kuidas Veidemann okupandiks sattus; Veidemann tegi koos Ojakääruga Rääma kooli hümni; Rein Kask. Meenutus

  9. Rein Raamat kunstnikest / Andri Ksenofontov

    Index Scriptorium Estoniae

    Ksenofontov, Andri, 1962-

    2009-01-01

    Dokumentaalfilm skulptor Jaan Varesest "Kahe peaga Jaanus", stsenarist ja režissöör Rein Raamat (Raamat-Film, 2009). Esilinastus 10. septembril Tallinna Kinomajas. Dokumentaalfilm "Siima Škopi muinasjutuline maailm", käsikiri Juta Kivimäe, režissöör Rein Raamat (Raamat-Film, 2009). Esilinastus 21. septembril Kumu auditooriumis

  10. Rein Raamat kunstnikest / Andri Ksenofontov

    Index Scriptorium Estoniae

    Ksenofontov, Andri, 1962-

    2009-01-01

    Dokumentaalfilm skulptor Jaan Varesest "Kahe peaga Jaanus", stsenarist ja režissöör Rein Raamat (Raamat-Film, 2009). Esilinastus 10. septembril Tallinna Kinomajas. Dokumentaalfilm "Siima Škopi muinasjutuline maailm", käsikiri Juta Kivimäe, režissöör Rein Raamat (Raamat-Film, 2009). Esilinastus 21. septembril Kumu auditooriumis

  11. Eesti Panga vaheehitus Tallinnas / Toomas Rein

    Index Scriptorium Estoniae

    Rein, Toomas, 1940-

    1999-01-01

    Arhitektuur, ruumikujundus, tehnilisi näitajaid. Kitsa vaheehituse Estonia pst. 11/13 projekteeris OÜ Arhitektuuribüroo Toomas Rein, arhitekt Toomas Rein. Sisekujundaja AS Stuudio Gadis, sisearhitekt Taevo Gans

  12. Anton Hansen Tammsaare Tõde / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2003-01-01

    Ilmunud ka kogumikus: Veidemann, Rein. Isiku tunnistus. Tallinn : SE & JS, 2006, lk. 221-224; Venek.: Pravda Antona Hansena Tammsaare / tlk. Marina Tervonen // Veidemann, Rein. Kollokvium po estonskoi literatute. Tallinn : Izd. "KPD", 2007, lk. 21-25

  13. Eesti Panga vaheehitus Tallinnas / Toomas Rein

    Index Scriptorium Estoniae

    Rein, Toomas, 1940-

    1999-01-01

    Arhitektuur, ruumikujundus, tehnilisi näitajaid. Kitsa vaheehituse Estonia pst. 11/13 projekteeris OÜ Arhitektuuribüroo Toomas Rein, arhitekt Toomas Rein. Sisekujundaja AS Stuudio Gadis, sisearhitekt Taevo Gans

  14. Tõlkimine kui avastamine / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2000-01-01

    Essee aluseks on ettekanne Tartu ülikooli semiootikaosakonna rahvusvahelisel seminaril "Kultuuritekst ja traditsioonitekst" 26. ja 27. nov. 1999. Ilmunud ka: Kultuuritekst ja traditsioonitekst. 26.-27. novembril 1999 Tartus toimunud seminari materjalid. - Tartu, 2000, lk. 63-70. Bibliograafia lk. 69. Kokkuvõte ingl. k. lk. 70; Veidemann, Rein. Tuikav tekst. Tartu : Tartu Ülikooli Kirjastus, 2006, lk. 196-202. Vene k.: Perevod kak otkrõtie / tlk. Marina Tervonen // Veidemann, Rein. Kollokvium po estonskoi literatute. Tallinn : Izd. "KPD", 2007, lk. 133-141

  15. Rein Pill tegi fantastilise sõidu / Rein Pill

    Index Scriptorium Estoniae

    Pill, Rein

    2008-01-01

    Septembris Chernjahovskis peetud CS14 taseme rahvusvahelistel ratsutamise takistussõiduvõistlustel tegi Rein Pill ajalugu, võites hobusel A Big Boy võistluste Grand Prix 160 cm kõrgusel parkuuril ja täites Euroopa meistrivõistluste kvalifikatsiooninormi

  16. Rein Lang : liitriiki ei tule / Rein Lang ; interv. Sten Hansson

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2003-01-01

    Ilmunud ka: Severnoje Poberezhje 16. juuli lk. 2, Lääne Elu 17. juuli lk. 4, Meie Maa 17. juuli lk. 2, Koit 17. juuli lk. 6, Vooremaa 17. juuli lk. 2, Hiiu Leht 22. juuli lk. 2, Nädaline 2. august lk. 4. Intervjuu Euroopa Liidu tulevikukonvendis osalenud Rein Lang'iga EL-i põhiseaduse projektist

  17. Rein Lang : liitriiki ei tule / Rein Lang ; interv. Sten Hansson

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2003-01-01

    Ilmunud ka: Severnoje Poberezhje 16. juuli lk. 2, Lääne Elu 17. juuli lk. 4, Meie Maa 17. juuli lk. 2, Koit 17. juuli lk. 6, Vooremaa 17. juuli lk. 2, Hiiu Leht 22. juuli lk. 2, Nädaline 2. august lk. 4. Intervjuu Euroopa Liidu tulevikukonvendis osalenud Rein Lang'iga EL-i põhiseaduse projektist

  18. Rein Pill tegi fantastilise sõidu / Rein Pill

    Index Scriptorium Estoniae

    Pill, Rein

    2008-01-01

    Septembris Chernjahovskis peetud CS14 taseme rahvusvahelistel ratsutamise takistussõiduvõistlustel tegi Rein Pill ajalugu, võites hobusel A Big Boy võistluste Grand Prix 160 cm kõrgusel parkuuril ja täites Euroopa meistrivõistluste kvalifikatsiooninormi

  19. Kirjandusloo semiootika poole / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2002-01-01

    Bibl. joonealustes märkustes. Resümee "Towards a semiotics of literary history", lk. 832. Järg artiklile "Kirjandusajalugu ja/kui kaos", Keel ja Kirjandus, 1999, nr. 12. Artikli alajaotised: Ajalugu ja kirjanduslugu ; Kirjandusloo mudelid ja kirjanduskriitika ; Eesti kirjandusloo mudelitest ; Kirjandusloo semiootika. Ilmunud ka: Veidemann, Rein. Tuikav tekst. Tartu : Tartu Ülikooli Kirjastus, 2006, lk. 171-173

  20. Rein Maran - Eesti looduse saadik maailmas / Rein Maran ; interv. Andres Laasik

    Index Scriptorium Estoniae

    Maran, Rein, 1931-

    2005-01-01

    Loodusfilmide meistril on esilinastunud uus film "Eesti kotkad". Lisad : "Rein Maran", "Digitaaltehnika muudab looduse elavamaks", "Eesti kõik kotkaliigid on kindlalt purgis", "Üliõpilased on Rein Maranile tänulikud"

  1. Rein Kilk : tahan saada Eesti suurimaks toiduainetöösturiks / Rein Kilk ; interv. Andres Reimer

    Index Scriptorium Estoniae

    Kilk, Rein, 1953-

    2007-01-01

    Suurärimees Rein Kilk vastab küsimustele, mis puudutavad Pere toiduainetetööstust ja teisi tema omanduses olevaid erinevatesse ärivaldkondadesse kuuluvaid ettevõtteid. Vt. samas: Rein Kilgiga seotud ettevõtted

  2. Rein Maran - Eesti looduse saadik maailmas / Rein Maran ; interv. Andres Laasik

    Index Scriptorium Estoniae

    Maran, Rein, 1931-

    2005-01-01

    Loodusfilmide meistril on esilinastunud uus film "Eesti kotkad". Lisad : "Rein Maran", "Digitaaltehnika muudab looduse elavamaks", "Eesti kõik kotkaliigid on kindlalt purgis", "Üliõpilased on Rein Maranile tänulikud"

  3. Rein Kilk : tahan saada Eesti suurimaks toiduainetöösturiks / Rein Kilk ; interv. Andres Reimer

    Index Scriptorium Estoniae

    Kilk, Rein, 1953-

    2007-01-01

    Suurärimees Rein Kilk vastab küsimustele, mis puudutavad Pere toiduainetetööstust ja teisi tema omanduses olevaid erinevatesse ärivaldkondadesse kuuluvaid ettevõtteid. Vt. samas: Rein Kilgiga seotud ettevõtted

  4. Kümnendikku riigikogust seovad peresidemed / Rein Sikk

    Index Scriptorium Estoniae

    Sikk, Rein, 1961-

    2007-01-01

    Vastvalitud riigikogus seovad kahtteist liiget perekondlikud sidemed. Vt. samas: Kas onupojapoliitika või juhus? Kommenteerivad: politoloog Rein Toomla, TÜ professor Marju Lauristin, TLÜ professor Rein Ruutsoo, emeriitprofessor Rein Taagepera

  5. Kümnendikku riigikogust seovad peresidemed / Rein Sikk

    Index Scriptorium Estoniae

    Sikk, Rein, 1961-

    2007-01-01

    Vastvalitud riigikogus seovad kahtteist liiget perekondlikud sidemed. Vt. samas: Kas onupojapoliitika või juhus? Kommenteerivad: politoloog Rein Toomla, TÜ professor Marju Lauristin, TLÜ professor Rein Ruutsoo, emeriitprofessor Rein Taagepera

  6. Rein Maran tähistab juubelit

    Index Scriptorium Estoniae

    2016-01-01

    85. sünnipäev on loodusdokumentalistil, kauaaegsel Tallinna Ülikooli filmiõppejõul ning filmiõppetooli juhil Rein Maranil. Balti filmi- ja meediakooli Supernova kinoülikool pühendab Rein Marani loomingule sügissemestri esimese filmiõhtu. Tallinna Ülikooli Nova maja 4. korruse kinokoridoris avatakse Rein Marani loomingule pühendatud näitus "Loodusfilmi tuhat nägu"

  7. Rein Maran tähistab juubelit

    Index Scriptorium Estoniae

    2016-01-01

    85. sünnipäev on loodusdokumentalistil, kauaaegsel Tallinna Ülikooli filmiõppejõul ning filmiõppetooli juhil Rein Maranil. Balti filmi- ja meediakooli Supernova kinoülikool pühendab sel puhul Rein Marani loomingule sügissemestri esimese filmiõhtu. Tallinna Ülikooli Nova maja 4. korruse kinokoridoris avatakse Rein Marani loomingule pühendatud näitus "Loodusfilmi tuhat nägu"

  8. Uskumatult põnev maailm läbi Rein Marani kaamerasilma / Rein Maran ; üles kirjutanud Alo Lõhmus

    Index Scriptorium Estoniae

    Maran, Rein, 1931-

    2011-01-01

    Valitud katkendeid Alo Lõhmuse koostatud peatselt ilmuvast Rein Marani filmilooraamatust "Ööbikut ei tohi reeta". Rein Maran tähistab 13. septembril 80. sünnipäeva. Andmeid Rein Marani elukäigu kohta

  9. Uskumatult põnev maailm läbi Rein Marani kaamerasilma / Rein Maran ; üles kirjutanud Alo Lõhmus

    Index Scriptorium Estoniae

    Maran, Rein, 1931-

    2011-01-01

    Valitud katkendeid Alo Lõhmuse koostatud peatselt ilmuvast Rein Marani filmilooraamatust "Ööbikut ei tohi reeta". Rein Maran tähistab 13. septembril 80. sünnipäeva. Andmeid Rein Marani elukäigu kohta

  10. 1 küsimus / Rein Raud

    Index Scriptorium Estoniae

    Raud, Rein

    2007-01-01

    Hiljuti andis kirjastus Kegan Paul välja Rein Raua koostatud kogumiku "Japan and Asian Modernities" (Jaapan ja Aasia modernsused), mis koondab teadusartiklid maailma tuntud Aasia uurijatelt Jaapanist, USAst, Prantsusmaalt, Hongkongist jne, sealhulgas on ka Rein Raua uurimus. Mis võiks olla kogumiku tähendus Eesti jaoks?

  11. Effects on behaviour and rein tension on horses ridden with or without martingales and rein inserts.

    Science.gov (United States)

    Heleski, C R; McGreevy, P D; Kaiser, L J; Lavagnino, M; Tans, E; Bello, N; Clayton, H M

    2009-07-01

    Unsteady hand position can cause discomfort to the horse, potentially leading to conflict behaviours (CB) such as head tossing or tail lashing. Some instructors feel that martingales or elastic rein inserts can reduce discomfort caused by inexperienced and unsteady hands. Others consider these devices to be inappropriate 'crutches'. Four horses and nine riders were tested under three conditions in random order: plain reins, adjustable training martingales (TM), and elasticised rein inserts (RI). Rein-tension data (7s) and behavioural data (30s) were collected in each direction. Rein-tension data were collected via strain-gauge transducers. Behavioural data were assessed using an ethogram of defined behaviours. No differences in the number of CB were observed. Mean rein tension for TM was higher than that of RI or controls. Relative to the withers, the head was lower for horses ridden with martingales. Carefully fitted martingales may have a place in riding schools that teach novices.

  12. Langi retseptid majanduse restartimiseks / Rein Lang

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2008-01-01

    Justiitsminister Rein Lang selgitab Maksumaksjale majanduse taaskäivitamise ideid, millest oli juttu 15. nov. 2008. aasta Reformierakonna majanduskonverentsil Restart ja Äripäev Onlines (15.11.2008)

  13. Ilmus Rein Neggo "Vastutuuli. I" / Hannes Oja

    Index Scriptorium Estoniae

    Oja, Hannes

    1999-01-01

    rets. rmt.: Vastutuuli. I : valimik EELK Los Angelese koguduse ajakirjas "Vastutuuli" (1950-1965) avaldatud kirjasõna / koostanud ja toimetanud Rein Neggo. Los Angeles : Eesti Evangeelse Luterliku Kiriku Los Angelese kogudus, 1999. 199 lk. : ill.

  14. Ilmus Rein Neggo "Vastutuuli. I" / Hannes Oja

    Index Scriptorium Estoniae

    Oja, Hannes

    1999-01-01

    rets. rmt.: Vastutuuli. I : valimik EELK Los Angelese koguduse ajakirjas "Vastutuuli" (1950-1965) avaldatud kirjasõna / koostanud ja toimetanud Rein Neggo. Los Angeles : Eesti Evangeelse Luterliku Kiriku Los Angelese kogudus, 1999. 199 lk. : ill.

  15. Rein Tammiku "Orgasmes" Vaalas / Eha Komissarov

    Index Scriptorium Estoniae

    Komissarov, Eha, 1947-

    1998-01-01

    Prantsusmaal elava kunstniku Rein Tammiku näitus "Orgasmes" 16. dets.-st 1988 9. jaan.-ni 1999 galeriis "Vaal". Kunstnik esitab "Väikeste Pariisi tüdrukute" sarja edasiarendust. Teema ئ erootika. Maal simuleerib fotograafiat.

  16. Rein Einasto : Eestis valitud ameerikalik valitsemise tee viib meid katastroofini / Rein Einasto ; interv. Kristi Leppik

    Index Scriptorium Estoniae

    Einasto, Rein, 1934-

    2008-01-01

    Kodanikuühiskonna edendamisest Eestis. Aasta missiooniinimese kandidaadiks esitatud professor Rein Einasto arvates päästaks meid avar mõtlemine, et viia inimkond tervikuna teisele teele. Praegune vaba turumajandus on pillamisele, raiskamisele ja kulutamisele üles ehitatud ummiktee. Lisa: Rein Einasto

  17. Rein Pakk: olen Jumala trumm, aga sina oled ka / Rein Pakk ; intervjueerinud Tiiu Laks

    Index Scriptorium Estoniae

    Pakk, Rein, 1968-

    2010-01-01

    Intervjuu Rein Pakuga, kellel meeldib kirjutada artikleid ja näidendeid, laval ja filmis mängida, teha sisekujunduslahendusi ja karikatuure. 27. augustil esietendus Tallinna Draamateatris tema esimene lavastajatöö, teatri Vanemuine lavastus "Kaos". Andmeid Rein Paku elu ja loomingu kohta

  18. Rein Einasto : Eestis valitud ameerikalik valitsemise tee viib meid katastroofini / Rein Einasto ; interv. Kristi Leppik

    Index Scriptorium Estoniae

    Einasto, Rein, 1934-

    2008-01-01

    Kodanikuühiskonna edendamisest Eestis. Aasta missiooniinimese kandidaadiks esitatud professor Rein Einasto arvates päästaks meid avar mõtlemine, et viia inimkond tervikuna teisele teele. Praegune vaba turumajandus on pillamisele, raiskamisele ja kulutamisele üles ehitatud ummiktee. Lisa: Rein Einasto

  19. Rein Pakk: olen Jumala trumm, aga sina oled ka / Rein Pakk ; intervjueerinud Tiiu Laks

    Index Scriptorium Estoniae

    Pakk, Rein, 1968-

    2010-01-01

    Intervjuu Rein Pakuga, kellel meeldib kirjutada artikleid ja näidendeid, laval ja filmis mängida, teha sisekujunduslahendusi ja karikatuure. 27. augustil esietendus Tallinna Draamateatris tema esimene lavastajatöö, teatri Vanemuine lavastus "Kaos". Andmeid Rein Paku elu ja loomingu kohta

  20. Director läks ja küsis : Milliste omadustega töötajaid te tahate tööle võtta ning millised inimesed teile ei sobi? / Janika Kuusik, Anni Pikk, Merike Jaamul... [jt.

    Index Scriptorium Estoniae

    2010-01-01

    Elioni personalijuht Janika Kuusik, TNT Eesti personalispetsialist Anni Pikk, Eesti Posti personalijuht Merike Jaamul, advokaadibüroo Sorainen personalijuht Kristiina Härms ning Webmedia personalijuht Kairi Pauskar vastavad küsimusele, milliseid inimesi nad eelistavad palgata

  1. Rein Aidma: "Ma ei lähe riigikogusse tukkuma" / Rein Aidma ; interv. Erik Gamzejev

    Index Scriptorium Estoniae

    Aidma, Rein, 1950-

    2003-01-01

    Ilmunud ka: Severnoje Poberezhje : Subbota 15. märts lk. 3. Riigikokku valitud Ida-Viru maavanem Rein Aidma astumisest Reformierakonda, möödunud valimiskampaaniast, Ida-Viru arengut pidurdavatest teguritest

  2. Rein Taagepera : "Euroopa peab muutuma föderatsiooniks" / Rein Taagepera ; interv. Teet Korsten

    Index Scriptorium Estoniae

    Taagepera, Rein, 1933-

    2008-01-01

    Ilmunud ka: Severnoje Poberezhje : Subbota 16. aug. lk. 5. Eesti/USA politoloog muutustest Eestis, Uppsala ülikooli Skytte auhinnast, konverentsist "Diasporaa roll Eesti iseseisvuse taastamisel?". Arvamust avaldab parlamendiliige Peeter Tulviste. Lisa: Rein Taagepera CV

  3. Mõõtmine ja intelligentsus / Rein Raud

    Index Scriptorium Estoniae

    Raud, Rein

    2007-01-01

    Geeniteadlane James Watson leidis, et Aafrikas elavate inimeste intelligentsustase ei ole võrdne valge nahavärviga inimeste omaga. Tallinna Ülikooli professor Rein Raud leiab, et selle väite peamine nõrkus on eeldus, et on vaid üks ja universaalne mõõtmisparameeter. Lisa: James Watson

  4. Tervistav ühiskonnavallatus / Rein Tootmaa

    Index Scriptorium Estoniae

    Tootmaa, Rein

    2003-01-01

    Lühimängufilm "Ferdinand" : stsenarist ja režissöör Andri Luup : produtsent Artur Talvik : operaatorid Rein Kotov ja Kristjan Jaak Nuudi : näitlejad Aleksander Eelmaa, Kaur Kender jt. : Allfilm 2002. Lisatud andmed Andri Luubi kohta

  5. Rein Raua kuraatoridebüüt

    Index Scriptorium Estoniae

    2001-01-01

    Hausi galeriis Rein Raua kureeritud rahvusvaheline kunstinäitus "KevadSuviSügisTalv. Murdumispunkt". Esinevad Eve Kask, Peeter Laurits, Dainius Lickevicius, Rehka Menon, Mall Nukke, Herkki Merila, Jorma Puranen, Rosita Raud, Ene-Liis Semper, Liina Siib, S. ja P. Stanikas

  6. Mõõtmine ja intelligentsus / Rein Raud

    Index Scriptorium Estoniae

    Raud, Rein

    2007-01-01

    Geeniteadlane James Watson leidis, et Aafrikas elavate inimeste intelligentsustase ei ole võrdne valge nahavärviga inimeste omaga. TLÜ professor Rein Raud leiab, et selle väite peamine nõrkus on eeldus, et on vaid üks ja universaalne mõõtmisparameeter

  7. Mõõtmine ja intelligentsus / Rein Raud

    Index Scriptorium Estoniae

    Raud, Rein, 1961-

    2007-01-01

    Geeniteadlane James Watson leidis, et Aafrikas elavate inimeste intelligentsustase ei ole võrdne valge nahavärviga inimeste omaga. TLÜ professor Rein Raud leiab, et selle väite peamine nõrkus on eeldus, et on vaid üks ja universaalne mõõtmisparameeter

  8. Zygmunt Bauman ja Rein Raud vestlesid kultuurist ja poliitikast

    Index Scriptorium Estoniae

    2014-01-01

    TLÜ Kultuuriteaduste ja kunstide doktorikooli kutsel Tallinnas viibinud sotsioloogi, Leedsi ülikooli emeriitprofessori Zygmunt Baumani ja TLÜ juhtivteadur Rein Raua vahel Kirjanike Liidu saalis toimunud avalikust vestlusest

  9. Lang : raudteeostu leping olgu avalik / Rein Lang ; interv. Hindrek Riikoja

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2006-01-01

    Justiitsminister Rein Lang vastab küsimustele, mis puudutavad majandusminister Edgar Savisaare tegevust raudtee taasriigistamisel ning Eesti Raudtee ostulepingut, pidades selle lepingu salastamist avaliku teabe seaduse rikkumiseks

  10. Lang : raudteeostu leping olgu avalik / Rein Lang ; interv. Hindrek Riikoja

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2006-01-01

    Justiitsminister Rein Lang vastab küsimustele, mis puudutavad majandusminister Edgar Savisaare tegevust raudtee taasriigistamisel ning Eesti Raudtee ostulepingut, pidades selle lepingu salastamist avaliku teabe seaduse rikkumiseks

  11. Honey Ants.

    Science.gov (United States)

    Conway, John R.

    1984-01-01

    Provides background information on honey ants. These ants are found in dry or desert regions of North America, Africa, and Australia. Also provides a list of activities using local species of ants. (JN)

  12. Rein Laur : arhitektuurne tervik maailmas pakutavast parimast / Gitte Hint

    Index Scriptorium Estoniae

    Hint, Gitte

    2003-01-01

    Korter Raekoja platsil. Sisearhitekt Rein Laur, tema kommentaarid. Võimalik on kasutada 70 erinevat valgustusviisi. Kujunduslikuks dominandiks on Yrjö Kukkapuro disainitud tool "Karusell". Seintel Anne Parmasto ja Rein Kelpmanni maalid. Vannitoa seinad on kaetud marmoriga. Ill.: plaan, 15 värv. vaadet

  13. Rein Ruutsoo: Vaenlase tegemine on ikka veel mõnede poliitikute ainus poliitika / Rein Ruutsoo

    Index Scriptorium Estoniae

    Ruutsoo, Rein, 1947-

    2007-01-01

    Nõukogude Eestist saladokumente Läände toimetanud Rein Ruutsoo kommenteerib riiklike teenetemärkide jagamist endistele kommunistidele president Arnold Rüütli ja president Toomas Hendrik Ilvese ajal. T.H. Ilves on arvanud autasustatavate hulka Eestimaa Kommunistliku Partei poolt juhitud ideoloogiatöö võitlejad Eesti Raadios Aarne Rannamäe ja Peeter Kaldre

  14. Rein Kilk ei loobu Pärnust / Rein Kilk ; interv. Tiiu Leis

    Index Scriptorium Estoniae

    Kilk, Rein, 1953-

    2007-01-01

    Ilmunud ka: Linnaleht : Tartu, 12. okt. 2007, lk. 7-8; Linnaleht : Pärnu, 12. okt. 2007, lk. 7-8. Suurärimees Rein Kilk vastab küsimustele vanade majade taastamisest, plaanidest Pärnus, suhtumisest heidikutesse. Kommenteerivad Peeter Raudsepp ja Elmar Lepp

  15. Rein Raamat tiris eestlased joonisfilmi juurde / Rein Raamat ; interv. Tiit Tuumalu

    Index Scriptorium Estoniae

    Raamat, Rein, 1931-

    2006-01-01

    Kunstnil, anima- ja dokumentaalfilmirežissöör tähistab 75-ndat sünnipäeva. 20. märtsil Kinomajas on autoriõhtu filmidega "Rein Raamat animatsiooni maailmas" ja "Kursi koolkond". Lisatud R. Raamatu loometee lühiandmed ning Priit Pärna kommentaar

  16. Rein Ruutsoo: Vaenlase tegemine on ikka veel mõnede poliitikute ainus poliitika / Rein Ruutsoo

    Index Scriptorium Estoniae

    Ruutsoo, Rein, 1947-

    2007-01-01

    Nõukogude Eestist saladokumente Läände toimetanud Rein Ruutsoo kommenteerib riiklike teenetemärkide jagamist endistele kommunistidele president Arnold Rüütli ja president Toomas Hendrik Ilvese ajal. T.H. Ilves on arvanud autasustatavate hulka Eestimaa Kommunistliku Partei poolt juhitud ideoloogiatöö võitlejad Eesti Raadios Aarne Rannamäe ja Peeter Kaldre

  17. Rein Raamat tiris eestlased joonisfilmi juurde / Rein Raamat ; interv. Tiit Tuumalu

    Index Scriptorium Estoniae

    Raamat, Rein, 1931-

    2006-01-01

    Kunstnil, anima- ja dokumentaalfilmirežissöör tähistab 75-ndat sünnipäeva. 20. märtsil Kinomajas on autoriõhtu filmidega "Rein Raamat animatsiooni maailmas" ja "Kursi koolkond". Lisatud R. Raamatu loometee lühiandmed ning Priit Pärna kommentaar

  18. Rein Kilk ei loobu Pärnust / Rein Kilk ; interv. Tiiu Leis

    Index Scriptorium Estoniae

    Kilk, Rein, 1953-

    2007-01-01

    Ilmunud ka: Linnaleht : Tartu, 12. okt. 2007, lk. 7-8; Linnaleht : Pärnu, 12. okt. 2007, lk. 7-8. Suurärimees Rein Kilk vastab küsimustele vanade majade taastamisest, plaanidest Pärnus, suhtumisest heidikutesse. Kommenteerivad Peeter Raudsepp ja Elmar Lepp

  19. Rein Ratase allkiri paneb rattad käima ; kommenteerinud Rein Ratas, Neeme Reinap, Vilmar Rei...[jt.

    Index Scriptorium Estoniae

    Jakobson, Kadri, 1970-

    2010-01-01

    Riigikogu keskkonnakomisjoni liige Rein Ratas surub läbi firma EcoPro, mille üks omanik on Ratase hea tuttav, arendust Saaremaal Ruhve poolsaarel, mis asub kaitsealal ja ehituskeeluvööndis. Rein Ratas on tuludeklaratsioonis jätnud märkimata firmast Adepte Ekspert saadava tulu

  20. Rein Randver : keskkonnaminister olen nüüd mina, mitte Villu Reiljan / Rein Randver ; interv. Rasmus Kagge

    Index Scriptorium Estoniae

    Randver, Rein, 1956-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 19. okt. lk. 4. Uus keskkonnaminister Rein Randver räägib talle varem esitatud ministriametite pakkumistest, oma tööplaanidest, avaldab seisukoha looduskaitsealuste maade vahetamise kohta. Lisa: Rein Randveri CV; Viis esimest tööd

  1. Rein Randver : keskkonnaminister olen nüüd mina, mitte Villu Reiljan / Rein Randver ; interv. Rasmus Kagge

    Index Scriptorium Estoniae

    Randver, Rein, 1956-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 19. okt. lk. 4. Uus keskkonnaminister Rein Randver räägib talle varem esitatud ministriametite pakkumistest, oma tööplaanidest, avaldab seisukoha looduskaitsealuste maade vahetamise kohta. Lisa: Rein Randveri CV; Viis esimest tööd

  2. Rein Ratase allkiri paneb rattad käima ; kommenteerinud Rein Ratas, Neeme Reinap, Vilmar Rei...[jt.

    Index Scriptorium Estoniae

    Jakobson, Kadri, 1970-

    2010-01-01

    Riigikogu keskkonnakomisjoni liige Rein Ratas surub läbi firma EcoPro, mille üks omanik on Ratase hea tuttav, arendust Saaremaal Ruhve poolsaarel, mis asub kaitsealal ja ehituskeeluvööndis. Rein Ratas on tuludeklaratsioonis jätnud märkimata firmast Adepte Ekspert saadava tulu

  3. Vaimsuse võlu / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2005-01-01

    Eesti Kultuurkapitali 2004. aasta kirjanduse aastapreemia laureaadid on: Rein Raud ("Hector ja Bernard"), fs (luulekogu "2004"), Mart Kivastik (näidend "Külmetava kunstniku portree"), Jaan Rannap ("Nelja nimega koer"), Toomas Haug ("Troojamäe tõotus"), Harald Rajamets (tõlkeluule kogumik "Pegasos ja peegel"), Antoine Chalvin ("Kalevipoja" tõlge prantsuse keelde"), Ilmar Talve ("Eesti kultuurilugu"), Lauri Sommer (artikkel Uku Masingu käsikirja "Saadik Magellani pilvest" vaimne, ajalis-ruumiline ja elulooline taust), Boris Tuch ("Gorjatshaja desjatka estonskihh pisatelei")

  4. Preemiad said Rein Raud, fs, Mart Kivastik

    Index Scriptorium Estoniae

    2005-01-01

    Eesti Kultuurkapitali 2004. aasta kirjanduse aastapreemia laureaadid on: Rein Raud ("Hector ja Bernard"), fs (luulekogu "2004"), Mart Kivastik (näidend "Külmetava kunstniku portree"), Jaan Rannap ("Nelja nimega koer"), Toomas Haug ("Troojamäe tõotus"), Harald Rajamets (tõlkeluule kogumik "Pegasos ja peegel"), Antoine Chalvin ("Kalevipoja" tõlge prantsuse keelde"), Ilmar Talve ("Eesti kultuurilugu"), Lauri Sommer (artikkel Uku Masingu käsikirja "Saadik Magellani pilvest" vaimne, ajalis-ruumiline ja elulooline taust), Boris Tuch ("Gorjatshaja desjatka estonskihh pisatelei")

  5. Preemiad said Rein Raud, fs, Mart Kivastik

    Index Scriptorium Estoniae

    2005-01-01

    Eesti Kultuurkapitali 2004. aasta kirjanduse aastapreemia laureaadid on: Rein Raud ("Hector ja Bernard"), fs (luulekogu "2004"), Mart Kivastik (näidend "Külmetava kunstniku portree"), Jaan Rannap ("Nelja nimega koer"), Toomas Haug ("Troojamäe tõotus"), Harald Rajamets (tõlkeluule kogumik "Pegasos ja peegel"), Antoine Chalvin ("Kalevipoja" tõlge prantsuse keelde"), Ilmar Talve ("Eesti kultuurilugu"), Lauri Sommer (artikkel Uku Masingu käsikirja "Saadik Magellani pilvest" vaimne, ajalis-ruumiline ja elulooline taust), Boris Tuch ("Gorjatshaja desjatka estonskihh pisatelei")

  6. Vaimsuse võlu / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2005-01-01

    Eesti Kultuurkapitali 2004. aasta kirjanduse aastapreemia laureaadid on: Rein Raud ("Hector ja Bernard"), fs (luulekogu "2004"), Mart Kivastik (näidend "Külmetava kunstniku portree"), Jaan Rannap ("Nelja nimega koer"), Toomas Haug ("Troojamäe tõotus"), Harald Rajamets (tõlkeluule kogumik "Pegasos ja peegel"), Antoine Chalvin ("Kalevipoja" tõlge prantsuse keelde"), Ilmar Talve ("Eesti kultuurilugu"), Lauri Sommer (artikkel Uku Masingu käsikirja "Saadik Magellani pilvest" vaimne, ajalis-ruumiline ja elulooline taust), Boris Tuch ("Gorjatshaja desjatka estonskihh pisatelei")

  7. TLÜ rektor Rein Raud valiti taas UNICA juhatusse / Maiki Voore

    Index Scriptorium Estoniae

    Voore, Maiki, 1983-

    2009-01-01

    Tallinna Ülikooli rektor Rein Raud valiti taas UNICA (Network of Universities from the Capitals of Europe) uue juhatuse liikmeks. UNICA rektorite 2010. aasta seminar otsustati korraldada Tallinna Ülikoolis

  8. Rein Müllerson - rahvusvahelise õiguse doktor / Eimar Rahumaa

    Index Scriptorium Estoniae

    Rahumaa, Eimar, 1948-

    1986-01-01

    1985. a. kaitses Rein Müllerson Moskva Riiklikus Ülikoolis doktoriväitekirja teemal "Rahvusvahelise avaliku, eraõiguse ja rahvusliku õiguse vahekord ning vastastikune mõju (teoreetilis-metodoloogiline uurimus)"

  9. Skandaalne kohukesereklaam võib olla ebaseaduslik / Rein Lang

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2005-01-01

    Ilmunud ka: Severnoje Poberezhje 5. okt. lk 2. Justiitsminister Rein Lang sõnul on AS-i Kohuke tellitud ja Keskerakonna reklaamibüroo tehtud reklaamis kasutatud kujundikeelt, mis on äravahetamiseni sarnane Keskerakonna valimisreklaamidega

  10. 48 minutit pommirühma elust / Rein Kotov

    Index Scriptorium Estoniae

    Kotov, Rein, 1965-

    1997-01-01

    Intervjuu R. Kotoviga, kuna Discovery Channel Europe näitab 30.10. dokumentaalfilmi "Profid. Pommirühm" ("Professionals : Bomb Squad"), stsenarist, režissöör ja operaator Rein Kotov : Inglismaa - Eesti - Taani 1997

  11. 48 minutit pommirühma elust / Rein Kotov

    Index Scriptorium Estoniae

    Kotov, Rein, 1965-

    1997-01-01

    Intervjuu R. Kotoviga, kuna Discovery Channel Europe näitab 30.10. dokumentaalfilmi "Profid. Pommirühm" ("Professionals : Bomb Squad"), stsenarist, režissöör ja operaator Rein Kotov : Inglismaa - Eesti - Taani 1997

  12. Kas võlad tapavad Kilgi lambakarja? / Rein Raudvere

    Index Scriptorium Estoniae

    Raudvere, Rein, 1955-

    2008-01-01

    Ärimees Rein Kilgile kuuluva lambakasvatusfirma Nurmus Grupp OÜ 4000pealist lambakarja ootab katastroof. Selgitusi lambakasvatusfirma olukorra kohta jagavad Palamuse vallavolikogu liige Enn Kivi, Nurmus Grupi OÜ tegevjuht Hillar Kalda, Jõgevamaa veterinaarkeskuse juhataja Harles Kaup ning juhataja asetäitja Arbo Kepp. Vt. samas: Firma võlausaldajatel on mõõt täis saamas; intervjuud ärimees Rein Kilgiga: Sügiseks saavad lambafirma võlad likvideeritud. Lisa: Loomad võlgade katteks tapamajja

  13. Kas võlad tapavad Kilgi lambakarja? / Rein Raudvere

    Index Scriptorium Estoniae

    Raudvere, Rein, 1955-

    2008-01-01

    Ärimees Rein Kilgile kuuluva lambakasvatusfirma Nurmus Grupp OÜ 4000pealist lambakarja ootab katastroof. Selgitusi lambakasvatusfirma olukorra kohta jagavad Palamuse vallavolikogu liige Enn Kivi, Nurmus Grupi OÜ tegevjuht Hillar Kalda, Jõgevamaa veterinaarkeskuse juhataja Harles Kaup ning juhataja asetäitja Arbo Kepp. Vt. samas: Firma võlausaldajatel on mõõt täis saamas; intervjuud ärimees Rein Kilgiga: Sügiseks saavad lambafirma võlad likvideeritud. Lisa: Loomad võlgade katteks tapamajja

  14. Arhitektuurne tervik maailmas pakutavast parimast : korter Raekoja platsil / Rein Laur, Yrjö Kukkapuro, Rein Kelpman...[jt.

    Index Scriptorium Estoniae

    2003-01-01

    plaan, 15 värv. vaadet; fotod: Kalle Veesaar; võimalik on kasutada 70 erinevat valgustusviisi; kujunduslikuks dominandiks on Yrjö Kukkapuro disainitud tool "Karusell"; seintel Anne Parmasto ja Rein Kelpmanni maalid; vannitoa seinad on kaetud marmoriga

  15. Isepäine modernist Toomas Rein / Toomas Rein ; intervjueerinud Mait Väljas ja Reet Varblane

    Index Scriptorium Estoniae

    Rein, Toomas, 1940-

    2010-01-01

    23. aprillil avatakse Eesti Arhitektuurimuuseumis arhitekt Toomas Reinu 70. sünnipäevale pühendatud näitus. Kataloogi ja näituse on koostanud Toomas Rein ja Mait Väljas, kujundanud Tiit Jürna. Toomas Rein endast, oma loomingust, eeskujudest, näitusest, nõukogude perioodi hoonete olukorrast, viimase aja töödest, koostööst teiste arhitektidega, teostamata projektidest

  16. Isepäine modernist Toomas Rein / Toomas Rein ; intervjueerinud Mait Väljas ja Reet Varblane

    Index Scriptorium Estoniae

    Rein, Toomas, 1940-

    2010-01-01

    23. aprillil avatakse Eesti Arhitektuurimuuseumis arhitekt Toomas Reinu 70. sünnipäevale pühendatud näitus. Kataloogi ja näituse on koostanud Toomas Rein ja Mait Väljas, kujundanud Tiit Jürna. Toomas Rein endast, oma loomingust, eeskujudest, näitusest, nõukogude perioodi hoonete olukorrast, viimase aja töödest, koostööst teiste arhitektidega, teostamata projektidest

  17. Stride-related rein tension patterns in walk and trot in the ridden horse

    NARCIS (Netherlands)

    Egenvall, Agneta; Roepstorff, Lars; Eisersiö, Marie; Rhodin, Marie; van Weeren, René

    2015-01-01

    BACKGROUND: The use of tack (equipment such as saddles and reins) and especially of bits because of rein tension resulting in pressure in the mouth is questioned because of welfare concerns. We hypothesised that rein tension patterns in walk and trot reflect general gait kinematics, but are also

  18. Rein tension acceptance in young horses in a voluntary test situation

    DEFF Research Database (Denmark)

    Christensen, Janne Winther; zharkikh, T.L.; Antoine, A.;

    2011-01-01

    Reasons for performing the study: During riding, horses are frequently exposed to pressure from the rider, e.g. through the bit and reins, but few studies have investigated at which point rein tension becomes uncomfortable for the horse. Objectives: To investigate how much rein tension young...

  19. Stride-related rein tension patterns in walk and trot in the ridden horse

    NARCIS (Netherlands)

    Egenvall, Agneta; Roepstorff, Lars; Eisersiö, Marie; Rhodin, Marie; van Weeren, René

    2015-01-01

    BACKGROUND: The use of tack (equipment such as saddles and reins) and especially of bits because of rein tension resulting in pressure in the mouth is questioned because of welfare concerns. We hypothesised that rein tension patterns in walk and trot reflect general gait kinematics, but are also det

  20. Ujumismedalite peensepistaja Rein Haljand sätib detailid paika / Jaan Martinson

    Index Scriptorium Estoniae

    Martinson, Jaan, 1960-

    2015-01-01

    Professor Rein Haljandi hoolealused võitsid ujumise MM-il Kaasanis hulga medaleid. Kinesioloogiaprofessorit, ujumistehnika spetsialisti Rein Haljandit seob Rootsi koondisega leping Rio de Janeiro olümpiamängude lõpuni. Rein Haljand jagab selgitusi ujumistehnika ja Rootsi ujumise eduloo kohta

  1. Beyond ANT

    DEFF Research Database (Denmark)

    Jansen, Till

    2017-01-01

    Actor-Network-Theory (ANT) offers an ‘infra-language’ of the social that allows one to trace social relations very dynamically, while at the same time dissolving human agency, thus providing a flat and de-centred way into sociology. However, ANT struggles with its theoretical design that may lead......, it offers an ‘infra-language’ of reflexive relations while maintaining ANT’s de-centred approach. This would enable us to conceptualize actor-networks as non-homogeneous, dynamic and connecting different societal rationales while maintaining the main strengths of ANT....

  2. Struggling Ants

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Some of China’s college graduates are barely scraping by The village of Tangjialing, 20 km north of down town Beijing, was thrust into the public consciousness in November. Publishers that month released a book titled Ants

  3. Le pouvoir d’une reine

    Directory of Open Access Journals (Sweden)

    Charles Garcia

    2006-08-01

    Full Text Available Les Chroniques anonymes de Sahagún rapportent les événements survenus dans cette ville au début du règne d’Urraque Ire de León-Castille. Or, curieusement, cette souveraine occupe une place relativement effacée dans la narration, bien qu’elle soit souvent dépeinte sous un jour favorable. Il faut dire que la reine, qui suivit la politique que son père avait engagée, fut d’un soutien constant pour les moines. Dans la Crónica, la vision positive d’Urraque, en tant que femme au pouvoir, contraste avec l’image que donnent d’elle les chroniques post-alphonsines. C’est donc à partir du croisement de ces sources, mais aussi d’autres documents, que nous tenterons de recomposer la place de cette femme à la tête du royaume et que nous essaierons de percer l’intention de l’image que donne l’auteur anonyme d’un récit bâti dans un but d’édification.Las Crónicas anónimas de Sahagún cuentan los acontecimientos que acaecieron en dicha ciudad en los primeros años del reinado de Urraca I de León-Castilla. No deja de extrañar que la reina no sea la principal protagonista del relato, aunque suela salir bien parada en él. Bien es verdad que la soberana no hizo sino proseguir una política favorable para con los benedictinos de Domnos Sanctos, una línea que ya había iniciado su padre. En la Crónica anónima la imagen positiva de Urraca, como mujer que ha conseguido izarse hasta el poder, contrasta con la percepción que de ella nos presentan las crónicas post-alfonsíes. Cruzando pues dichas fuentes, con otros más documentos, intentaremos acercarnos al papel que esta mujer desempeñó al frente del reino, así como al retrato que de ella hace el cronista anónimo en un relato que escribió con clara intención ejemplificadora.

  4. Kui Rahvarinne äratas eesti rahvuse / Rein Ruutsoo

    Index Scriptorium Estoniae

    Ruutsoo, Rein, 1947-

    2008-01-01

    13. aprillil 20 aastat tagasi ETV telesaates "Mõtleme veel" Edgar Savisaare poolt välja hõigatud Rahvarinde loomise idee käivitas Eestis võimsa rahvaliikumise, mille kaasabil murdis Eesti end vabadusse. Intervjuu sotsiaalteadlase Rein Ruutsooga

  5. Ant Farm

    OpenAIRE

    2012-01-01

    Publié à l’occasion de l’exposition d’Ant Farm au Frac Centre du 12 au 23 décembre 2007, ce très beau catalogue, qui fait état des dix ans de création du collectif californien, propose un nombre important de documents iconographiques, de notices et de textes concernant leurs différents projets. Fondé en 1968 par Doug Michels et Chip Lord, rejoints par la suite par Curtis Schreier, Hudson Marquez, Douglas Hurr et d’autres encore, le collectif Ant Farm a marqué les esprits par quelques œuvres s...

  6. Neutrinos and other matters collected works of Frederic Reines

    CERN Document Server

    Reines, Frederick; Moe, Michael; Price, LeRoy R; Schultz, J; Sobel, H

    This volume is a collection of the scientific papers of Frederick Reines. Its publication is to commemorate the 70th birthday, in 1988, of this distinguished scientist. The selected papers here cover many aspects of his work in neutrino physics, astrophysics and conservation law tests. They have been divided into logical groupings, each introduced by a leading authority in that field, who helps the reader to see the reprinted articles with a better historical and scientific perspective.

  7. Telegramme sent on June 14 1956 from physicists Fred Reines and Clyde Cowan to Wolfgang Pauli announcing the detection, for the first time, of neutrinos. The Physics Nobel Prize in 1995 was awarded to Reines for this discovery.

    CERN Multimedia

    Maximiliem Brice

    2006-01-01

    Telegramme sent on June 14 1956 from physicists Fred Reines and Clyde Cowan to Wolfgang Pauli announcing the detection, for the first time, of neutrinos. The Physics Nobel Prize in 1995 was awarded to Reines for this discovery.

  8. The Ants Have It!

    Science.gov (United States)

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  9. The Ants Have It!

    Science.gov (United States)

    Daugherty, Belinda

    2001-01-01

    Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)

  10. Rein Kilk jätab oma võlad maksmata / Kadi Heinsalu

    Index Scriptorium Estoniae

    Heinsalu, Kadi, 1966-

    2007-01-01

    Ärimees Rein Kilk registreeris oma Zelluloosi vabaajakeskust ehitanud ja arendanud firma AS-i L.Rei Nõva valda Läänemaal ning ettevõtte juhatusse kuulub ainuisikuliselt ettevõtete likvideerimisega tegelev Silver Eensaar. Vt. samas: Rein Kilk: kahju tekitas firma eelmine juhtkond; Kinnistud liikunud teistesse firmadesse; Zelluloosi kompleksi varade liikumine

  11. Fire Ant Allergy

    Science.gov (United States)

    ... Treatments ▸ Library ▸ Allergy Library ▸ Fire ant allergy Share | Fire Ant Allergy This article has been reviewed by Thanai Pongdee, MD, FAAAAI Fire ants are a stinging insect typically found in ...

  12. Fire Ant Bites

    Science.gov (United States)

    ... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...

  13. Rein and Zheng Elected to American Academy of Microbiology | Poster

    Science.gov (United States)

    By Nancy Parrish, Staff Writer Earlier this year, Alan Rein, Ph.D., and Zhi-Ming (Thomas) Zheng, M.D., Ph.D., were elected to fellowship in the American Academy of Microbiology, the honorific leadership group within the American Society for Microbiology (ASM). They were among 88 microbiologists who were elected to the academy “through a highly selective, peer-review process, based on their records of scientific achievement and original contributions that have advanced microbiology,” according to the society’s website.

  14. Identification of Haptic Based Guiding Using Hard Reins

    Science.gov (United States)

    Ranasinghe, Anuradha; Dasgupta, Prokar; Althoefer, Kaspar; Nanayakkara, Thrishantha

    2015-01-01

    This paper presents identifications of human-human interaction in which one person with limited auditory and visual perception of the environment (a follower) is guided by an agent with full perceptual capabilities (a guider) via a hard rein along a given path. We investigate several identifications of the interaction between the guider and the follower such as computational models that map states of the follower to actions of the guider and the computational basis of the guider to modulate the force on the rein in response to the trust level of the follower. Based on experimental identification systems on human demonstrations show that the guider and the follower experience learning for an optimal stable state-dependent novel 3rd and 2nd order auto-regressive predictive and reactive control policies respectively. By modeling the follower’s dynamics using a time varying virtual damped inertial system, we found that the coefficient of virtual damping is most appropriate to explain the trust level of the follower at any given time. Moreover, we present the stability of the extracted guiding policy when it was implemented on a planar 1-DoF robotic arm. Our findings provide a theoretical basis to design advanced human-robot interaction algorithms applicable to a variety of situations where a human requires the assistance of a robot to perceive the environment. PMID:26201076

  15. Identification of Haptic Based Guiding Using Hard Reins.

    Directory of Open Access Journals (Sweden)

    Anuradha Ranasinghe

    Full Text Available This paper presents identifications of human-human interaction in which one person with limited auditory and visual perception of the environment (a follower is guided by an agent with full perceptual capabilities (a guider via a hard rein along a given path. We investigate several identifications of the interaction between the guider and the follower such as computational models that map states of the follower to actions of the guider and the computational basis of the guider to modulate the force on the rein in response to the trust level of the follower. Based on experimental identification systems on human demonstrations show that the guider and the follower experience learning for an optimal stable state-dependent novel 3rd and 2nd order auto-regressive predictive and reactive control policies respectively. By modeling the follower's dynamics using a time varying virtual damped inertial system, we found that the coefficient of virtual damping is most appropriate to explain the trust level of the follower at any given time. Moreover, we present the stability of the extracted guiding policy when it was implemented on a planar 1-DoF robotic arm. Our findings provide a theoretical basis to design advanced human-robot interaction algorithms applicable to a variety of situations where a human requires the assistance of a robot to perceive the environment.

  16. Raamatukogudest läks kaduma info tuhandete raamatute kohta / Rein Sikk

    Index Scriptorium Estoniae

    Sikk, Rein, 1961-

    2011-01-01

    Detsembris 2010 kadusid infosüsteemi URRAM kasutavate raamatukogude arvutitest laenutusandmed, probleemid lugejateeninduses võivad kesta nädalaid. Vt. ka Sikk, Rein. Kultuuriministeeriumi sovetlik digitüng, lk. 2

  17. "She ain't no human being": le rock anglais chante sa reine

    OpenAIRE

    Chastagner, Claude

    1995-01-01

    The Beatles, The Smiths and The Sex Pistols have all sung the Queen, to celebrate or denigrate her. But in all cases, it is the sacrificial victim more than the human being or the official figure that is put forward.; The Beatles, The Smiths et The Sex Pistols ont tous les trois chanté la reine, une reine vilipendée ou célébrée mais toujours posée comme une victime sacrificielle.

  18. Rein Veidemann: meil oli valida - nüüd või mitte kunagi / Rein Veidemann ; küsitles Tõnu Prei

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2007-01-01

    Intervjuu Rein Veidemanniga, kes oli üks 1991.a. augustiputši päevil Eesti iseseisvust kinnitava otsuse poolt hääletanud 69 rahvasaadikust. Ülemnõukogu 20. augusti otsust peab ta sama tähtsaks kui Eesti Vabariigi väljakuulutamist 1918. aastal

  19. Reformierakonna "korrapidaja" riigikogus Rein Aidma: "Vajaliku hääletustulemuse saavutamisele eelneb peen mäng" / Rein Aidma ; interv. Erik Gamzejev

    Index Scriptorium Estoniae

    Aidma, Rein, 1950-

    2007-01-01

    Ilmunud ka: Severnoje Poberezhje : Subbota, 28. juuli 2007, lk. 5. Ida-Virumaalt Riigikokku valitud Rein Aidma roll erakonna fraktsiooni aseesimehena, saadikute ja riigiametnike privileegidest, Reformierakonna populaarsusest, riigiraha jagamisest. Arvamust avaldavad Jaanus Rahumägi ja Agu Värimäe

  20. Reformierakonna "korrapidaja" riigikogus Rein Aidma: "Vajaliku hääletustulemuse saavutamisele eelneb peen mäng" / Rein Aidma ; interv. Erik Gamzejev

    Index Scriptorium Estoniae

    Aidma, Rein, 1950-

    2007-01-01

    Ilmunud ka: Severnoje Poberezhje : Subbota, 28. juuli 2007, lk. 5. Ida-Virumaalt Riigikokku valitud Rein Aidma roll erakonna fraktsiooni aseesimehena, saadikute ja riigiametnike privileegidest, Reformierakonna populaarsusest, riigiraha jagamisest. Arvamust avaldavad Jaanus Rahumägi ja Agu Värimäe

  1. Rein Veidemann: meil oli valida - nüüd või mitte kunagi / Rein Veidemann ; küsitles Tõnu Prei

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2007-01-01

    Intervjuu Rein Veidemanniga, kes oli üks 1991.a. augustiputši päevil Eesti iseseisvust kinnitava otsuse poolt hääletanud 69 rahvasaadikust. Ülemnõukogu 20. augusti otsust peab ta sama tähtsaks kui Eesti Vabariigi väljakuulutamist 1918. aastal

  2. Alternatives to conventional evaluation of rideability in horse performance tests: suitability of rein tension and behavioural parameters.

    Science.gov (United States)

    König von Borstel, Uta; Glißman, Chantal

    2014-01-01

    Rideability, i.e. the ease and comfort with which a horse can be ridden, is considered to be one of the most important traits in riding horses. However, at present rideability is evaluated rather subjectively in breeding horse performance tests. The aim of the present study was to evaluate the role horse behaviour as well as degree and quality of rein tension might play in judges' evaluation of horses' rideability. Mares (n=33) and stallions (n=13) from two different mare- and one stallion-testing station were observed twice during their performance test dressage training. During these rides, rein tension was measured continuously, and frequency of behaviour patterns such as head-tossing, tail swishing, and snorting was recorded. Rein tension parameters showed reasonable repeatabilities within horse-rider pairs (e.g. mean rein tension: r(2)=0.61 ± 0.11; variance of rein tension: r(2)=0.52 ± 0.14). Regression analysis revealed that a larger proportion of variance in rideability scores could be explained by maximum (17%), mean (16%) and variance (15%) of rein tension compared to horses' or riders' behavioural parameters (tail-swishing: 5% and rider's use of hands: 5%, respectively). According to mixed model analysis, rideability scores dropped (all Prider comfort and horse welfare, potentially, measurements of rein tension along with behaviour observations assessing the quality of rein contact (e.g. distinguishing a light contact from attempts to evade contact) might be used to make the assessment of rideability more impartial.

  3. Riigikogulased ongi teistmoodi asendis. Aga mitte nii teistmoodi, kui nad hetkel arvavad / Rein Taagepera ; interv. Urmo Soonvald

    Index Scriptorium Estoniae

    Taagepera, Rein, 1933-

    2007-01-01

    Politoloog Rein Taagepera vastab Riigikogu suurust, tööd ning seaduseelnõu, mis vabastab parlamendiliikmed kuluhüvitiste avalikustamisest, puudutavatele küsimustele. Lisa: Soome parlamendist õpitakse kulutamist, mitte tööl käimist; Rein Taagepera: teadlane, presidendikandidaat, Res Publica looja

  4. Riigikogulased ongi teistmoodi asendis. Aga mitte nii teistmoodi, kui nad hetkel arvavad / Rein Taagepera ; interv. Urmo Soonvald

    Index Scriptorium Estoniae

    Taagepera, Rein, 1933-

    2007-01-01

    Politoloog Rein Taagepera vastab Riigikogu suurust, tööd ning seaduseelnõu, mis vabastab parlamendiliikmed kuluhüvitiste avalikustamisest, puudutavatele küsimustele. Lisa: Soome parlamendist õpitakse kulutamist, mitte tööl käimist; Rein Taagepera: teadlane, presidendikandidaat, Res Publica looja

  5. Riding with the ants

    NARCIS (Netherlands)

    Duarte, A. P. M.; Attili-Angelis, D.; Baron, N. C.; Groenewald, Johannes Z.; Crous, Pedro W.; Pagnocca, F. C.

    Isolates of Teratosphaeriaceae have frequently been found in the integument of attine ants, proving to be common and diverse in this microenvironment. The LSU phylogeny of the ant-isolated strains studied revealed that they cluster in two main lineages. The first was associated with the genus

  6. Riding with the ants

    NARCIS (Netherlands)

    Duarte, A.P.M.; Attili-Angelis, D.; Baron, N.C.; Groenewald, J.Z.; Crous, P.W.; Pagnocca, F.C.

    2017-01-01

    Isolates of Teratosphaeriaceae have frequently been found in the integument of attine ants, proving to be common and diverse in this microenvironment. The LSU phylogeny of the ant-isolated strains studied revealed that they cluster in two main lineages. The first was associated with the genus Xenope

  7. Riding with the ants

    NARCIS (Netherlands)

    Duarte, A. P. M.; Attili-Angelis, D.; Baron, N. C.; Groenewald, Johannes Z.; Crous, Pedro W.; Pagnocca, F. C.

    2016-01-01

    Isolates of Teratosphaeriaceae have frequently been found in the integument of attine ants, proving to be common and diverse in this microenvironment. The LSU phylogeny of the ant-isolated strains studied revealed that they cluster in two main lineages. The first was associated with the genus Xenope

  8. Minister Rein Lang ärkas hilja / Väinu Rozental, Kaisa Tahlfeld ; kommenteerinud Arvo Kivikas

    Index Scriptorium Estoniae

    Rozental, Väinu, 1957-

    2009-01-01

    Firmajuhid ei näe justiitsminister Rein Langi palgakärpe seaduse idees suurt kasu, sest erasektor juba vähendab töötajate palka. Vt. samas: Lang: palgakärbe on alternatiiv koondamisele ja firma sulgemisele. Diagramm

  9. Rein Pilli hobusel on hüppamine sisse kodeeritud / Maarja Värv

    Index Scriptorium Estoniae

    Värv, Maarja

    2008-01-01

    Tänavusest aastast A Big Boyga ratsutav takistussõitja Rein Pill võitis septembri alguses Venemaal kõrgetasemelise maailmakarikaetapi ning püüab saavutust korrata ka Tallinn International Horse Show'l. Lisa: Takistussõidu grand prix' rajaskeem

  10. Pärandkultuuri väärtustades ja kaitstes / Rein Einasto

    Index Scriptorium Estoniae

    Einasto, Rein, 1934-

    2009-01-01

    Looduslike ja loodud kultuuriväärtuste kaitsmise vajadusest. Teemaga seoses tutvustatakse kahte raamatut: Väike pärandkultuuri käsiraamat / Lembitu Tarang, Kristiina Hellström, Rein Kaljuvee ... jt. Tartu : Eesti Loodusfoto, 2007; Kõivupuu, Marju. Hinged puhkavad puudes. Tallinn : Huma, 2009

  11. Rein Taaramäe virutas protestiks liidrisärgi porri ja katkestas / Jaan Martinson

    Index Scriptorium Estoniae

    Martinson, Jaan, 1960-

    2007-01-01

    Velotuuri Tour de Le Pays Roannaisþ finishis jäi Rein Taaramäe koos klubikaaslaste Tanel Kangerti ja Kalle Kriidiga enne joont seisma, võttis seljast liidrisärgi ja viskas selle protestiks porri. Eestlased olid viimasel etapil suunatud valele teele, kuid kohtunik sõitu ei peatanud

  12. Kallavere külas tehti ajalugu / Rein Veski ; interv. Merike Metstak

    Index Scriptorium Estoniae

    Veski, Rein, 1933-

    2008-01-01

    Vestlus raamatu "KallΜuΜro. LillΜuerΜ. Pasies 1241-2006 : külalood = Kallavere. Lillevere. Pasies : the past, present and future of the villages" (Tallinn : Rootsi-Kallavere Küla Selts, 2008) projektijuhi ja toimetaja Rein Veskiga. Samas kommenteerinud: Kase, Priit. Kallavere küla oma raamat

  13. Biometry by ultrasonography of the epaxial and pelvic musculature in equines trained with Pessoa's rein

    Directory of Open Access Journals (Sweden)

    Kátia de Oliveira

    2014-11-01

    Full Text Available This study aimed to evaluate the use of Pessoa's rein in training equine, as a support in exercise training, on biometry by ultrasonography of the epaxial (Longíssimus Dorsi, Gluteus Medius e Musculus Multifidus and pelvic musculature (Biceps Femoris e Semitendinosus. Thereby, eight Quarter Horse mares was used, with eight years on average age, 400kg of body weight, trained with the Pessoa's rein twice a week, for two months. Variables were measured before and after training, consisting of assessment thickness (cm of the Longíssimus Dorsi and cross-sectional area (cm2 of muscles, Gluteus Medius, Biceps Femoris, Semitendinosus and Musculus Multifidus. It observed a significant effect of training with Pessoa's rein, on the Biceps Femoris (P<0.01 and Musculus Multifidus (P<0.01, which the average cross-sectional area at the final evaluation were of 28.66cm2 and 14.29cm2, respectively. Thus it can be conclude that training with Pessoa's rein modifies muscular function, promoting hypertrophy Musculus Multifidus and Biceps Femoris of horses

  14. Üliõpilased valisid aasta tudengisõbraks Rein Raua

    Index Scriptorium Estoniae

    2012-01-01

    Eesti Üliõpilaskondade Liit valis aasta tudengisõbraks Rein Raua, kes on tugevalt väljendanud ja kaitsnud üliõpilasliikumise jaoks olulisi seisukohti, nagu akadeemiline vabadus, tasuta õpe ja tudengite sotsiaalsed garantiid. Ära märgitud ka teised tunnustuse saajad

  15. A note on Rhipilia nigrescens Coppejans & Prud’homme van Reine (Chlorophyta)

    NARCIS (Netherlands)

    Coppejans, E.; Prud’homme van Reine, W.F.

    1990-01-01

    In our paper on seaweeds of the Snellius-II expedition (Coppejans & Prud’homme van Reine, 1989) we suggested that the new species Rhipilia nigrescens had been described in Phycologia. Due to regulations of that journal and corroborated by the short spell between acceptance and publication in Blumea,

  16. Rein Pill võitis Venemaal kõrgetasemelise võistluse / Maarja Värv

    Index Scriptorium Estoniae

    Värv, Maarja

    2008-01-01

    Ratsutaja Rein Pill tegi Venemaal Tsherjahovskis CS14* taseme rahvusvahelistel ratsutamise takistussõiduvõistlustel ajalugu, võites hobusel A Big Boy võistluste Grand Prix' 160 cm kõrgusel parkuuril ja täites seega Euroopa meistrivõistluste kvalifikatsiooninormi

  17. Milline oli teie esimene töökoht? / Raivo Vare, Rein Lang, Hans H Luik

    Index Scriptorium Estoniae

    Vare, Raivo, 1958-

    2002-01-01

    Oma esimest töökohta meenutavad Tallinna abilinnapea, AS-i Trio LSL nõukogu esimees Rein Lang, AS-i Pakterminal juhatuse esimees Raivo Vare ja Eesti Ekspressi vastutav väljaandja ning Ekspress Grupi nõukogu liige Hans H. Luik

  18. Mess TEHNOLOOGIA 2000 - teaduse, tehnika ja rahamaailma kohtumine / Rein Ruubel, Mart Min ; interv. Urmi Reinde

    Index Scriptorium Estoniae

    Ruubel, Rein

    2000-01-01

    Maikuus Tallinna Tehnikaülikoolis toimunud messi eesmärgiks oli ülevaate saamine innovaatilise ettevõtluse seisust ning arengu- ja arendamisvõimalustest Eestis : Vestlus messi projektijuhi Rein Ruubeli ja Elektroonika Instituudi direktori, professor Mart Miniga

  19. Rein Pill võitis Venemaal kõrgetasemelise võistluse / Maarja Värv

    Index Scriptorium Estoniae

    Värv, Maarja

    2008-01-01

    Ratsutaja Rein Pill tegi Venemaal Tsherjahovskis CS14* taseme rahvusvahelistel ratsutamise takistussõiduvõistlustel ajalugu, võites hobusel A Big Boy võistluste Grand Prix' 160 cm kõrgusel parkuuril ja täites seega Euroopa meistrivõistluste kvalifikatsiooninormi

  20. Scaling of crystal field parameters between Pd 2REIn and Pd 2RESn

    Science.gov (United States)

    Babateen, M.; Neumann, K.-U.; Ziebeck, K. R. A.

    1995-02-01

    Experimentally it is found that crystal field (CF) parameters between the same rare earth compounds in the alloy series Pd 2REIn and Pd 2RESn (RE = rare earth element) exhibit scaling properties. A phenomenological model is put forward to explain this observation.

  1. Tavatu juhtum / Toomas Rein, Helle Gans, Leonhard Lapin ; interv. Reet Varblane

    Index Scriptorium Estoniae

    Rein, Toomas, 1940-

    2007-01-01

    Arhitektid Toomas Rein ja Leonhard Lapin ning sisearhitekt Helle Gans meenutavad Valgevene näidiskolhoosile Rassvet projekteeritud lasteaeda, mis valmis 1987. aastal. Kompleks pälvis 1987. a. NSVL Arhitektide Liidu preemia ja üleliidulise ametiühingupreemia

  2. Rüütli asemel peaks Moskvasse sõitma Rein Lang

    Index Scriptorium Estoniae

    2005-01-01

    Peaminister Juhan Parts, välisminister Rein Lang ja kaitseminister Jaak Jõerüüt otsustasid töökohtumisel, et 9. mai pidustustel Moskvas võiks Eestit president Arnold Rüütli minematajätmise korral esindada välisminister. Ilmunud ka Järva Teataja, 2005/Mar/8, lk. 1

  3. Kes on Eesti teaduses tegijad? / Mats Estonius, Andres Metspalu, Rein Vaikmäe, Martin Zobel

    Index Scriptorium Estoniae

    2008-01-01

    Küsimusele vastavad Tallinna Ülikooli teadusprorektor Mats Estonius, Tartu Ülikooli biotehnoloogia professor Andres Metspalu, Tallinna Tehnikaülikooli teadusprorektor, teaduspoliitika komisjoni liige Rein Vaikmäe, Tartu Ülikooli taimeökoloogia professor, teaduskompetentsi nõukogu esimees Martin Zobel

  4. Üliõpilased valisid aasta tudengisõbraks Rein Raua

    Index Scriptorium Estoniae

    2012-01-01

    Eesti Üliõpilaskondade Liit valis aasta tudengisõbraks Rein Raua, kes on tugevalt väljendanud ja kaitsnud üliõpilasliikumise jaoks olulisi seisukohti, nagu akadeemiline vabadus, tasuta õpe ja tudengite sotsiaalsed garantiid. Ära märgitud ka teised tunnustuse saajad

  5. Mess TEHNOLOOGIA 2000 - teaduse, tehnika ja rahamaailma kohtumine / Rein Ruubel, Mart Min ; interv. Urmi Reinde

    Index Scriptorium Estoniae

    Ruubel, Rein

    2000-01-01

    Maikuus Tallinna Tehnikaülikoolis toimunud messi eesmärgiks oli ülevaate saamine innovaatilise ettevõtluse seisust ning arengu- ja arendamisvõimalustest Eestis : Vestlus messi projektijuhi Rein Ruubeli ja Elektroonika Instituudi direktori, professor Mart Miniga

  6. Alternatives to conventional evaluation of rideability in horse performance tests: suitability of rein tension and behavioural parameters.

    Directory of Open Access Journals (Sweden)

    Uta König von Borstel

    Full Text Available Rideability, i.e. the ease and comfort with which a horse can be ridden, is considered to be one of the most important traits in riding horses. However, at present rideability is evaluated rather subjectively in breeding horse performance tests. The aim of the present study was to evaluate the role horse behaviour as well as degree and quality of rein tension might play in judges' evaluation of horses' rideability. Mares (n=33 and stallions (n=13 from two different mare- and one stallion-testing station were observed twice during their performance test dressage training. During these rides, rein tension was measured continuously, and frequency of behaviour patterns such as head-tossing, tail swishing, and snorting was recorded. Rein tension parameters showed reasonable repeatabilities within horse-rider pairs (e.g. mean rein tension: r(2=0.61 ± 0.11; variance of rein tension: r(2=0.52 ± 0.14. Regression analysis revealed that a larger proportion of variance in rideability scores could be explained by maximum (17%, mean (16% and variance (15% of rein tension compared to horses' or riders' behavioural parameters (tail-swishing: 5% and rider's use of hands: 5%, respectively. According to mixed model analysis, rideability scores dropped (all P<0.05 with increasing mean, maximum and variability in rein tension (e.g. -0.37 ± 0.14 scores per additional 10 Newton in mean tension. However, mean rein tension differed between testing stations (P<0.0001 ranging between 9.1 ± 1.6 N in one station and 21.7 ± 1.3 N in another station. These results indicate that quantity and consistency of rein tension is either directly or indirectly an important factor for judges to derive rideability scores. Given the importance of rein tension parameters to both rider comfort and horse welfare, potentially, measurements of rein tension along with behaviour observations assessing the quality of rein contact (e.g. distinguishing a light contact from attempts to evade

  7. The first mesozoic ants.

    Science.gov (United States)

    Wilson, E O; Carpenter, F M; Brown, W L

    1967-09-01

    Two worker ants preserved in amber of Upper Cretaceous age have been found in New Jersey. They are the first undisputed remains of social insects of Mesozoic age, extending the existence of social life in insects back to approximately 100 million years. They are also the earliest known fossils that can be assigned with certainty to aculeate Hymenoptera. The species, Sphecomyrma freyi, is considered to represent a new subfamily (Sphecomyrminae), more primitive than any previously known ant group. It forms a near-perfect link between certain nonsocial tiphiid wasps and the most primitive myrmecioid ants.

  8. Lapsed ja digikultuur / Katrin Kuusik

    Index Scriptorium Estoniae

    Kuusik, Katrin

    2015-01-01

    Vestlusest TLÜ BFMi koolitusjuhi ja laste filmikooli juhendajaga tema poolt laste ja õpetajatega läbi viidud hariduslikest projektidest, mille eesmärgiks on tutvustada ja rakendada erinevaid filmi ja animatsiooni nippe koolitöös

  9. Field techniques for sampling ants

    Science.gov (United States)

    Ants occur in most environments and ecologists ask a diverse array of questions involving ants. Thus, a key consideration in ant studies is to match the environment and question (and associated environmental variables) to the ant sampling technique. Since each technique has distinct limitations, usi...

  10. Sick ants become unsociable.

    Science.gov (United States)

    Bos, N; Lefèvre, T; Jensen, A B; d'Ettorre, P

    2012-02-01

    Parasites represent a severe threat to social insects, which form high-density colonies of related individuals, and selection should favour host traits that reduce infection risk. Here, using a carpenter ant (Camponotus aethiops) and a generalist insect pathogenic fungus (Metarhizium brunneum), we show that infected ants radically change their behaviour over time to reduce the risk of colony infection. Infected individuals (i) performed less social interactions than their uninfected counterparts, (ii) did not interact with brood anymore and (iii) spent most of their time outside the nest from day 3 post-infection until death. Furthermore, infected ants displayed an increased aggressiveness towards non-nestmates. Finally, infected ants did not alter their cuticular chemical profile, suggesting that infected individuals do not signal their physiological status to nestmates. Our results provide evidence for the evolution of unsociability following pathogen infection in a social animal and suggest an important role of inclusive fitness in driving such evolution.

  11. Record dynamics in ants.

    Directory of Open Access Journals (Sweden)

    Thomas O Richardson

    Full Text Available The success of social animals (including ourselves can be attributed to efficiencies that arise from a division of labour. Many animal societies have a communal nest which certain individuals must leave to perform external tasks, for example foraging or patrolling. Staying at home to care for young or leaving to find food is one of the most fundamental divisions of labour. It is also often a choice between safety and danger. Here we explore the regulation of departures from ant nests. We consider the extreme situation in which no one returns and show experimentally that exiting decisions seem to be governed by fluctuating record signals and ant-ant interactions. A record signal is a new 'high water mark' in the history of a system. An ant exiting the nest only when the record signal reaches a level it has never perceived before could be a very effective mechanism to postpone, until the last possible moment, a potentially fatal decision. We also show that record dynamics may be involved in first exits by individually tagged ants even when their nest mates are allowed to re-enter the nest. So record dynamics may play a role in allocating individuals to tasks, both in emergencies and in everyday life. The dynamics of several complex but purely physical systems are also based on record signals but this is the first time they have been experimentally shown in a biological system.

  12. Utilization of Anting-Anting (Acalypha indica) Leaves as Antibacterial

    Science.gov (United States)

    Batubara, Irmanida; Wahyuni, Wulan Tri; Firdaus, Imam

    2016-01-01

    Anting-anting (Acalypha indica) plants is a species of plant having catkin type of inflorescence. This research aims to utilize anting-anting as antibacterial toward Streptococcus mutans and degradation of biofilm on teeth. Anting-anting leaves were extracted by maceration technique using methanol, chloroform, and n-hexane. Antibacterial and biofilm degradation assays were performed using microdilution technique with 96 well. n-Hexane extracts of anting-anting leaves gave the best antibacterial potency with minimum inhibitory concentration and minimum bactericidal concentration value of 500 μg/mL and exhibited good biofilm degradation activity. Fraction of F3 obtained from fractionation of n-hexane's extract with column chromatography was a potential for degradation of biofilm with IC50 value of 56.82 μg/mL. Alkaloid was suggested as antibacterial and degradation of biofilm in the active fraction.

  13. [The development of Rein van Bemmelens (1904-1983) undation theory: forty years of Dutch geology].

    Science.gov (United States)

    Barzilay, Willemjan

    2009-01-01

    The Dutch geologist Rein van Bemmelen was the greatest opponent of plate tectonics in The Netherlands. He lived and worked during an important period in the history of earth sciences. He had studied geology when Wegeners theory was introduced and enthusiastically received in the Netherlands and he worked as a geologists during the period in which, after Wegeners theory was rejected in The Netherlands, several Dutch geologists came with their own theories to explain the origin of continents and oceans and in which plate tectonics was introduced in The Netherlands. He had proposed his own theory, the undation theory, at the beginning of the 1930s and kept on developing it during the following years. He continued to do so until his death in 1983. The history of the undation theory thus sheds light on the history of geology in The Netherlands. I will trace the history of geology in The Netherlands using Rein van Bemmelen and his undation theory as a lens.

  14. Rein: Taming Tail Latency in Key-Value Stores via Multiget Scheduling

    KAUST Repository

    Reda, Waleed

    2017-04-17

    We tackle the problem of reducing tail latencies in distributed key-value stores, such as the popular Cassandra database.We focus on workloads of multiget requests, which batch together access to several data elements and parallelize read operations across the data store machines. We first analyze a production trace of a real system and quantify the skew due to multiget sizes, key popularity, and other factors. We then proceed to identify opportunities for reduction of tail latencies by recognizing the composition of aggregate requests and by carefully scheduling bottleneck operations that can otherwise create excessive queues. We design and implement a system called Rein, which reduces latency via inter-multiget scheduling using low overhead techniques. We extensively evaluate Rein via experiments in Amazon Web Services (AWS) and simulations. Our scheduling algorithms reduce the median, 95, and 99 percentile latencies by factors of 1.5, 1.5, and 1.9, respectively.

  15. Rein Tammik : Pidu katku ajal = Feast during the plague / Anneli Porri

    Index Scriptorium Estoniae

    Epner, Eero, 1978-

    2007-01-01

    Rein Tammiku fotorealistlik pildimaailm on iseseisev organism, mis ajuti genereerib ootamatuid tähenduslikke lühiühendusi. Erinevalt loodusmaalijatest, portreemaalijatest, meremaalijatest ja teistest maalib Rein Tammik pilte. Ta on pildimaalija. Tammikut huvitavad eelkõige visuaalsed paradoksid. Tammik asus juba 1970. aastail ajastuid ühte pilti kokku keevitama. Rembrandti grupiportreele «Kangrute gildi eesistujaist» ilmusid «Visarite» näod, Manet’ «Eine murul» leidis järsku aseme punaruudulisel linal jne. Historitsistlik eklektika - postmodernismi peamisi strateegiaid - on Tammiku loomingus täiesti selgelt loetav, teda on nimetatud esimeseks nõukogude postmodernistiks. Teatav nõukogude ajastu traumaatiline tajumine ilmneb tema töödes suuresti igatsusest kestvuse, jätkuvuse ja üldkehtivuse järele, mida 1970-1980-ndad aastad ei võimaldanud. 1992. aastast resideerub Prantsusmaal

  16. Rein Tammik : Pidu katku ajal = Feast during the plague / Anneli Porri

    Index Scriptorium Estoniae

    Epner, Eero, 1978-

    2007-01-01

    Rein Tammiku fotorealistlik pildimaailm on iseseisev organism, mis ajuti genereerib ootamatuid tähenduslikke lühiühendusi. Erinevalt loodusmaalijatest, portreemaalijatest, meremaalijatest ja teistest maalib Rein Tammik pilte. Ta on pildimaalija. Tammikut huvitavad eelkõige visuaalsed paradoksid. Tammik asus juba 1970. aastail ajastuid ühte pilti kokku keevitama. Rembrandti grupiportreele «Kangrute gildi eesistujaist» ilmusid «Visarite» näod, Manet’ «Eine murul» leidis järsku aseme punaruudulisel linal jne. Historitsistlik eklektika - postmodernismi peamisi strateegiaid - on Tammiku loomingus täiesti selgelt loetav, teda on nimetatud esimeseks nõukogude postmodernistiks. Teatav nõukogude ajastu traumaatiline tajumine ilmneb tema töödes suuresti igatsusest kestvuse, jätkuvuse ja üldkehtivuse järele, mida 1970-1980-ndad aastad ei võimaldanud. 1992. aastast resideerub Prantsusmaal

  17. De ontwikkelingsgeschiedenis van Rein van Bemmelens (1904-1983 undatietheorie: veertig jaar Nederlandse geologie

    Directory of Open Access Journals (Sweden)

    Willemjan Barzilay

    2009-03-01

    Full Text Available The development of Rein van Bemmelens (1904-1983 undation theory: Forty years of Dutch geology The Dutch geologist Rein van Bemmelen was the greatest opponent of plate tectonics in the Netherlands. He lived and worked during an important period in the history of earth sciences. He had studied geology when Wegeners theory was introduced and enthusiastically received in the Netherlands and he worked as a geologists during the period in which, after Wegeners theory was rejected in the Netherlands, several Dutch geologists came with their own theories to explain the origin of continents and oceans and in which plate tectonics was introduced in the Netherlands. He had proposed his own theory, the undation theory, at the beginning of the 1930s and kept on developing it during the following years. He continued to do so until his death in 1983. The history of the undation theory thus sheds light on the history of geology in the Netherlands. I will trace the history of geology in the Netherlands using Rein van Bemmelen and his undation theory as a lense.

  18. Ant Colony Optimization for Control

    NARCIS (Netherlands)

    Van Ast, J.M.

    2010-01-01

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

  19. Ant Colony Optimization for Control

    NARCIS (Netherlands)

    Van Ast, J.M.

    2010-01-01

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

  20. Sick ants become unsociable

    DEFF Research Database (Denmark)

    Bos, Nicky Peter Maria; Lefevre, T.; Jensen, A.B.

    2012-01-01

    Parasites represent a severe threat to social insects, which form high-density colonies of related individuals, and selection should favour host traits that reduce infection risk. Here, using a carpenter ant (Camponotus aethiops) and a generalist insect pathogenic fungus (Metarhizium brunneum), w...

  1. ANT i arbejdslivsforskningen

    DEFF Research Database (Denmark)

    2012-01-01

    for Tidsskrift for Arbejdsliv at stille skarpt på, hvorledes teknologi kan forstås og udforskes, og her står nyere teoridannelser som STS (Science- and Technology Studies) og ANT (Actor-Network Theory) centralt. Dette temanummer af tidsskriftet har derfor disse teorier og deres anvendelse i studier af arbejdsliv...

  2. Tiny, Powerful, Awesome Ants!

    Science.gov (United States)

    Tate, Kathleen

    2007-01-01

    Peering through a thematic science lens--elementary students embarked on a one-week study of ants during a month-long summer school program. This integrated unit addressed reading and writing skills while developing the science-process skills of observation, inferring, and communicating in a motivating and authentic way. Pre- and post-assessments…

  3. The Dynamics of Foraging Ants

    Science.gov (United States)

    Baxter, G. William

    2009-03-01

    We experimentally study the foraging of small black ants, Formicinae lasius flavus, in order to describe their foraging behavior mathematically. Individual ants are allowed to forage on a two-dimensional surface in the absence of any food sources. The position of the ant as a function of time is determined using a high-resolution digital camera. Analysis of the average square displacements of many ants suggests that the foraging strategy is a non-reversing random walk. Moreover, the ants do not retrace their steps to return home but instead continue the random walk until it brings them back near their starting point.

  4. "Ant-egg" cataract revisited

    DEFF Research Database (Denmark)

    Clemmensen, Kåre; Enghild, Jan J; Ivarsen, Anders;

    2017-01-01

    PURPOSE: Hereditary congenital cataract varies immensely concerning location and form of the lens opacities. A specific and very rare phenotype is called "ant-egg" cataract first described in 1900. "Ant-eggs" have previously been examined using light microscopy, backscattered electron imaging and X......-ray scans and electron microscopy. The purpose of this study was to further characterize "ant-egg" cataract using modern technology and display the history of the "ant-eggs" after cataract extraction. METHODS: "Ant-eggs" were examined using Heidelberg SPECTRALIS Optical Coherence Tomography (OCT......-egg" structures in "ant-egg" cataract. Eighteen of these proteins are not natively found in the human lens. Moreover, "ant-eggs" do not vary over time, after cataract extraction, regarding size and location....

  5. Ante la ley

    Directory of Open Access Journals (Sweden)

    Kafka Franz

    1999-12-01

    Full Text Available Ante las puertas de la ley hay un guardian. Un campesino se llega hasta ese guardian y le pide que le permita entra en la ley, pero el guardian le dice que por ahora no se lo puede permitir. El hombre reflexiona y entonces pregunta si podria entrar despues. Es posible -dice el guardian-; pero no ahora. La puerta de entrada a la ley esta abierta como siempre.

  6. Carcinoïde primitif du rein métastasant après 12 ans

    Science.gov (United States)

    Bacha, Dhouha; Lahmar, Ahlem; Gharbi, Lassad; Slama, Sana Ben; Bouraoui, Saadia; Chatti, Samia; Regaya, Sabeh Mzabi

    2016-01-01

    Les carcinoïdes primitifs du rein sont rares avec une centaine de cas rapportés dans la littérature. Sur le plan histologique, il s'agit d'une tumeur bien différenciée dont la morphologie rejoint souvent celle des carcinoïdes dans les autres localisations. Nous rapportons un cas de carcinoïde primitif du rein survenant chez un homme de 41 ans, découvert à la suite de métastases hépatiques. La tumeur était particulière par son architecture tubulo-papillaire, suggérant à tort le diagnostic de carcinome papillaire du rein. Ce diagnostic a été redressé 12 ans après, à la suite de l'apparition d'autres métastases hépatiques, osseuses et pulmonaires. PMID:27217899

  7. Distributed nestmate recognition in ants.

    Science.gov (United States)

    Esponda, Fernando; Gordon, Deborah M

    2015-05-07

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response.

  8. "Ant-egg" cataract revisited.

    Science.gov (United States)

    Clemmensen, Kåre; Enghild, Jan J; Ivarsen, Anders; Riise, Ruth; Vorum, Henrik; Heegaard, Steffen

    2017-01-01

    Hereditary congenital cataract varies immensely concerning location and form of the lens opacities. A specific and very rare phenotype is called "ant-egg" cataract first described in 1900. "Ant-eggs" have previously been examined using light microscopy, backscattered electron imaging and X-ray scans and electron microscopy. The purpose of this study was to further characterize "ant-egg" cataract using modern technology and display the history of the "ant-eggs" after cataract extraction. "Ant-eggs" were examined using Heidelberg SPECTRALIS Optical Coherence Tomography (OCT)(Heidelberg Engineering, Heidelberg, Germany). Ten "ant-eggs" were extracted; four of these as well as control tissue were analyzed by mass spectrometry (AB Sciex). Proteins were identified and their approximate abundances were determined. Immunohistochemical staining was carried out on the remaining "ant-eggs" for cytokeratin and S100. In anterior OCT-images, the "ant-egg" structures are localized on the iris. Comparative pictures showed that they stayed in the same location for more than 45 years. Mass spectrometry of "ant-eggs" yielded a proteome of 56 different proteins. Eighteen of the 56 "ant-egg" proteins (32 %) were neither present in our controls nor in a known fetal lens proteome. Among these were cytokeratin and Matrix-Gla protein. Immunohistochemical reactions were positive for cytokeratin and S100. This study demonstrates the previously unknown protein composition of the "ant-egg" structures in "ant-egg" cataract. Eighteen of these proteins are not natively found in the human lens. Moreover, "ant-eggs" do not vary over time, after cataract extraction, regarding size and location.

  9. [RDPLF and Rein, 2 complementary registries: a comparison of the collected data].

    Science.gov (United States)

    Couchoud, Cécile; Duman, Mirela; Frimat, Luc; Ryckelynck, Jean-Philippe; Verger, Christian

    2007-03-01

    The 2 registries RDPLF and Rein are information systems concerning the treatment of end-stage renal disease. The aim of the study was to evaluate the representativeness and exhaustivity of the recorded cases as well as the accuracy of the informations in the 2 registries. Were included 375 adults, who started a first ESRD treatment between 1 January 2003 and 31 December 2003 in 7 French regions and were treated by peritoneal dialysis (PD) on the first day of the 4th month of ESRD treatment. 264 patients were identified found in both registries. Age, body mass index and albuminemia didn't differ significantly. The mean haemoglobin level was higher in RDPLF. There was a good concordance on sex, diabetes status but less so on primary renal disease and PD modalities. There were significant discrepancies between the two registries on the date of the first treatment. The analysis of outcomes (transplantation or death) showed 8 discrepancies related to the lack of recording of the event in one of the 2 registries. The good global agreement observed between Rein and RDPLF for the common data emphasizes the fiability and representativeness of the 2 structures and the synergy of their activities for a best evaluation of the quality of peritoneal dialysis. This study shows the necessity of a common patient identification that will allow us to maintain a good complementarity between the 2 registries and will favour common studies.

  10. Feng shui väärtus on vaimujõus / Marika Tomberg ; komment. Lea Eermann, komment. Rein Weber

    Index Scriptorium Estoniae

    Tomberg, Marika

    1999-01-01

    Feng shui järgi korraldatud Lea Eermanni kodust Nõmmel. Feng shui- ja geobioloogia-alase nõustamisega tegelev arhitekt Rein Weber keskkonna mõjust tervisele, magamistoast. Enda ja maja kaitsmisest halbade mõjude eest. 10 illustratsiooni

  11. Kas tõesti viimane liivlane elab Kanadas? / Alo Lõhmus ; kommenteerinud Vahur Laiapea ja Tiit-Rein Viitso

    Index Scriptorium Estoniae

    Lõhmus, Alo

    2010-01-01

    Režissöör Vahur Laiapea plaanist teha liivi keele teemaline film läänemeresoome keelte emeriitprofessorist Tiit-Rein Viitsost. Tegevuse käigus leiti Kanadast teadaolevalt vanim liivi keelt emakeelena kõnelev liivlanna Grizelda Kristina

  12. Õpilaskodud ei ole imerohi, aga rohi siiski / Rein Ansip, Pille Liblik, Kalev Saar...[jt.

    Index Scriptorium Estoniae

    2009-01-01

    Õpilaskodude kasvatajate suvekoolis Krabil arutlesid sotsiaalsete probleemidega kodudest pärit laste koolitamise üle Krabi põhikooli direktor Ale Sprenk, Varstu vallavanem Rein Ansip, Võru maavalitsuse haridusosakonna juhataja Pille Liblik, Viira kooli direktor Kalev Saar ja psühholoog Tõnu Ots

  13. Scaling of crystal field parameters between Pd{sub 2}REIn and Pd{sub 2}RESn

    Energy Technology Data Exchange (ETDEWEB)

    Babateen, M. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom); Neumann, K.U. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom); Ziebeck, K.R.A. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom)

    1995-02-09

    Experimentally it is found that crystal field (CF) parameters between the same rare earth compounds in the alloy series Pd{sub 2}REIn and Pd{sub 2}RESn (RE=rare earth element) exhibit scaling properties. A phenomenological model is put forward to explain this observation. ((orig.)).

  14. Feng shui väärtus on vaimujõus / Marika Tomberg ; komment. Lea Eermann, komment. Rein Weber

    Index Scriptorium Estoniae

    Tomberg, Marika

    1999-01-01

    Feng shui järgi korraldatud Lea Eermanni kodust Nõmmel. Feng shui- ja geobioloogia-alase nõustamisega tegelev arhitekt Rein Weber keskkonna mõjust tervisele, magamistoast. Enda ja maja kaitsmisest halbade mõjude eest. 10 illustratsiooni

  15. Temperature: Human Regulating, Ants Conforming

    Science.gov (United States)

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  16. The metapleural gland of ants.

    Science.gov (United States)

    Yek, Sze Huei; Mueller, Ulrich G

    2011-11-01

    The metapleural gland (MG) is a complex glandular structure unique to ants, suggesting a critical role in their origin and ecological success. We synthesize the current understanding of the adaptive function, morphology, evolutionary history, and chemical properties of the MG. Two functions of the MG, sanitation and chemical defence, have received the strongest empirical support; two additional possible functions, recognition odour and territorial marking, are less well supported. The design of the MG is unusual for insects; glandular secretions are stored in a rigid, non-compressible invagination of the integument and the secretion is thought to ooze out passively through the non-closable opening of the MG or is groomed off by the legs and applied to target surfaces. MG loss has occurred repeatedly among the ants, particularly in the subfamilies Formicinae and Myrmicinae, and the MG is more commonly absent in males than in workers. MG chemistry has been characterized mostly in derived ant lineages with unique biologies (e.g. leafcutter ants, fire ants), currently precluding any inferences about MG chemistry at the origin of the ants. A synthetic approach integrating functional morphology, phylogenetic transitions and chemical ecology of the MGs of both the derived and the unstudied early-branching (basal) ant lineages is needed to elucidate the evolutionary origin and diversification of the MG of ants.

  17. Temperature: Human Regulating, Ants Conforming

    Science.gov (United States)

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  18. Invasive ants of Bermuda revisited

    Directory of Open Access Journals (Sweden)

    James K. Wetterer

    2017-02-01

    Full Text Available For 60+ years, two of the world’s most widespread and destructive invasive ant species, the African big-headed ant (Pheidole megacephala from tropical Africa and the Argentine ant (Linepithema humile from subtropical South America, have been engaged in an epic battle on the islands of Bermuda. Both species are completely intolerant of the other and are also well-known for killing off native invertebrates, particularly other ants. Here I surveyed sites across Bermuda in 2016, including resurveys of the locations previously surveyed in 1963, 1966, 1973, 1986, and 2002, to provide an update on this conflict. The status of all other ant species present in the islands, including previous records from literature, is also provided. In addition, I surveyed ants nesting in red mangrove (Rhizophora mangle trees to evaluate whether this arboreal habitat may serve as a refuge for previously overlooked ant species. In 2016, L. humile occurred at most surveyed sites in Bermuda, including all ten resurveyed sites. Pheidole megacephala was present at only two resurveyed sites, a lower proportion of sites than any of the five earlier surveys. Still, P. megacephala occupied substantial areas, particularly in and around Hamilton, the capital of Bermuda. This survey increased the number of ant species with verified records from Bermuda to 25, including four exotic species recorded for the first time: Cardiocondyla minutior, Pheidole navigans, Strumigenys emmae, and Strumigenys membranifera. I found five ant species nesting in mangroves: L. humile plus four Old World exotics, C. minutior, Cardiocondyla obscurior, Monomorium floricola, and Plagiolepis alluaudi. It appears that L. humile may be better suited to the subtropical climate of Bermuda than P. megacephala, except perhaps in warmer and sunnier habitats, such as plantings along urban streets and in open parks, where P. megacephala may hold the advantage. The dataset on the new ant records from 2016 is

  19. Hospitales seguros ante desastres

    Directory of Open Access Journals (Sweden)

    Celso Vladimir Bambaren Alatrista

    2007-07-01

    Full Text Available Entre 1982 a 2005 se registraron daños en 1 143 establecimientos de salud en el Perú, generalmente debido a sismos, lluvias e inundaciones. Los daños en los servicios de salud producen la interrupción de la atención de la población y de los programas de salud, así como generan un gran gasto para la rehabilitación y reconstrucción. Por ello, se requiere proteger a los establecimientos de salud y desarrollar una política de hospitales seguros ante desastres que incluya medidas para prevenir o reducción de la vulnerabilidad estructural, no estructural y funcional en los nuevos establecimientos y en los existentes.(Rev Med Hered 2007;18:149-154.

  20. FORMIDABEL: The Belgian Ants Database.

    Science.gov (United States)

    Brosens, Dimitri; Vankerkhoven, François; Ignace, David; Wegnez, Philippe; Noé, Nicolas; Heughebaert, André; Bortels, Jeannine; Dekoninck, Wouter

    2013-01-01

    FORMIDABEL is a database of Belgian Ants containing more than 27.000 occurrence records. These records originate from collections, field sampling and literature. The database gives information on 76 native and 9 introduced ant species found in Belgium. The collection records originated mainly from the ants collection in Royal Belgian Institute of Natural Sciences (RBINS), the 'Gaspar' Ants collection in Gembloux and the zoological collection of the University of Liège (ULG). The oldest occurrences date back from May 1866, the most recent refer to August 2012. FORMIDABEL is a work in progress and the database is updated twice a year. THE LATEST VERSION OF THE DATASET IS PUBLICLY AND FREELY ACCESSIBLE THROUGH THIS URL: http://ipt.biodiversity.be/resource.do?r=formidabel. The dataset is also retrievable via the GBIF data portal through this link: http://data.gbif.org/datasets/resource/14697 A dedicated geo-portal, developed by the Belgian Biodiversity Platform is accessible at: http://www.formicidae-atlas.be FORMIDABEL is a joint cooperation of the Flemish ants working group "Polyergus" (http://formicidae.be) and the Wallonian ants working group "FourmisWalBru" (http://fourmiswalbru.be). The original database was created in 2002 in the context of the preliminary red data book of Flemish Ants (Dekoninck et al. 2003). Later, in 2005, data from the Southern part of Belgium; Wallonia and Brussels were added. In 2012 this dataset was again updated for the creation of the first Belgian Ants Atlas (Figure 1) (Dekoninck et al. 2012). The main purpose of this atlas was to generate maps for all outdoor-living ant species in Belgium using an overlay of the standard Belgian ecoregions. By using this overlay for most species, we can discern a clear and often restricted distribution pattern in Belgium, mainly based on vegetation and soil types.

  1. Runtime analysis of the 1-ANT ant colony optimizer

    DEFF Research Database (Denmark)

    Doerr, Benjamin; Neumann, Frank; Sudholt, Dirk

    2011-01-01

    The runtime analysis of randomized search heuristics is a growing field where, in the last two decades, many rigorous results have been obtained. First runtime analyses of ant colony optimization (ACO) have been conducted only recently. In these studies simple ACO algorithms such as the 1-ANT...... are investigated. The influence of the evaporation factor in the pheromone update mechanism and the robustness of this parameter w.r.t. the runtime behavior have been determined for the example function OneMax.This work puts forward the rigorous runtime analysis of the 1-ANT on the example functions Leading......Ones and BinVal. With respect to Evolutionary Algorithms (EAs), such analyses were essential to develop methods for the analysis on more complicated problems. The proof techniques required for the 1-ANT, unfortunately, differ significantly from those for EAs, which means that a new reservoir of methods has...

  2. [SIMS REIN: a multi-source information system for end-stage renal disease].

    Science.gov (United States)

    Landais, Paul; Simonet, Ana; Guillon, Didier; Jacquelinet, Christian; Ben Saïd, Mohamed; Mugnier, Claude; Simonet, Michel

    2002-04-01

    In France, the prevalence of End-Stage Renal Disease (ESRD) is not precisely known. The sources of information are scattered and not coordinated. Consequently, care is ill adapted to meet the demand. The Multi-Source Information System is the basis of the Renal Epidemiology and Information Network (REIN). It is dedicated to improve and organise our medical and epidemiological knowledge of ESRD and to aid public health decision-making in this area. The proposed approach is based on the datawarehouses. This model allows a unified vision of scattered data into distinct databases, for a better management, be it particular (patient follow-up) or global (regional follow-up), with a finality of aid in decision-making. Several categories of problems were considered: the global conception of the information system, the organisation of the datawarehouse, which offers different viewpoints of the data, the integration of heterogeneous data coming from different sources, data exchange and definition of a specific ontology.

  3. Ex uno plures´est e pluribus unum´ini? / Rein Müllerson ; inglise keelest tõlkinud Marek Laane

    Index Scriptorium Estoniae

    Müllerson, Rein, 1944-

    2010-01-01

    Õigusteadlane Rein Müllerson ühiskondliku mitmekesisuse ja homogeensuse arengutest, dissimilatsiooni asendumisest assimilatsiooniga, Ida ja Lääne ühiskondade ühildumisest üleilmastumise protsessis

  4. Rein Raud on Tallinna Ülikooli uus juht : 20 keelt valdav Raud lubab ülikoolist teha teadusasutuse, mille ümber koondub pealinna hariduseliit / Anneli Lepp

    Index Scriptorium Estoniae

    Lepp, Anneli

    2006-01-01

    Eile Tallinna Ülikooli uueks rektoriks valitud Rein Raud lubab teha kõik selleks, et ülikoolist saaks rahvusvaheline teadusasutus, mille juhtimisel võetakse senisest rohkem kuulda ka tudengite häält

  5. Ex uno plures´est e pluribus unum´ini? / Rein Müllerson ; inglise keelest tõlkinud Marek Laane

    Index Scriptorium Estoniae

    Müllerson, Rein, 1944-

    2010-01-01

    Õigusteadlane Rein Müllerson ühiskondliku mitmekesisuse ja homogeensuse arengutest, dissimilatsiooni asendumisest assimilatsiooniga, Ida ja Lääne ühiskondade ühildumisest üleilmastumise protsessis

  6. Pest repelling properties of ant pheromones

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2014-01-01

    Ants control pests via predation and physical deterrence; however, ant communication is based on chemical cues which may serve as warning signals to potential prey and other intruders. The presence of ant pheromones may, thus, be sufficient to repel pests from ant territories. This mini...

  7. Pest repellent properties of ant pheromones

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2012-01-01

    Many ant species are efficient control agents against a wide range of pest insects in many crops. They control pest insects via predation; however, ant communication is based on chemical cues which may be eavesdropped by potential prey and serve as chemical warning signals. Thus, the presence...... of ant pheromones may be sufficient to repel pest insects from ant territories. The study of ant semiochemicals is in its infancy, yet, evidence for their potential use in pest management is starting to build up. Pheromones from four of five tested ant species have been shown to deter herbivorous insect...... prey and competing ant species are also deterred by ant deposits, whereas ant symbionts may be attracted to them. Based on these promising initial findings, it seems advisable to further elucidate the signaling properties of ant pheromones and to test and develop their use in future pest management....

  8. ANT, tourism and situated globality

    DEFF Research Database (Denmark)

    Jóhannesson, Gunnar Thór; Ren, Carina Bregnholm; van der Duim, René

    2015-01-01

    are used to define as the separate spheres of nature and culture. This paper explores and relates the central tenets of ANT in tourism with regard to the concept of the Anthropocene. It presents the ANT approach as a flat and object-oriented ontology and methodology and explores its potentials to carve out......In recent years Actor-network theory (ANT) has increasingly been felt in the field of tourism studies (Van der Duim, Ren, & Jóhannesson, 2012). An important implication of the meeting between ANT and tourism studies is the notion of tourism being described as a heterogeneous assemblage of what we...... viable descriptions of the collective condition of humans and more-than-humans in the Anthropocene. Also and moving past a merely descriptive approach, it discusses it as a useful tool to engage with the situated globalities which come into being through the socio-spatial coupling of tourism...

  9. Ants Orase kultuurisõnum

    Index Scriptorium Estoniae

    2007-01-01

    26. jaanuaril toimub Tallinna Ülikooli Akadeemilises Raamatukogus seminar silmapaistvast Eesti teadlasest ja tõlkijast Ants Orasest. Esinevad kirjandusteadlased Tallinna Ülikoolist, Tartu Ülikoolist ja Eesti Kirjandusmuuseumist. Avaettekandeks on sõna Oklahoma Ülikooli professoril Vincent B. Leitchil, kes oli Ants Orase viimaseks juhendatavaks doktorandiks. Seminari korraldavad Tallinna Ülikool ja Eesti Kirjandusmuuseum. Vt ka Postimees, 26, jaan., lk. 18

  10. Rein Maran soovitab / Rein Maran

    Index Scriptorium Estoniae

    Maran, Rein, 1931-

    2007-01-01

    Silmas pidades 19. septembril avatavat 5. Matsalu rahvusvahelist loodusfilmide festivali kirjutab autor loodusfilmi rollist ja olemusest ning tutvustab Gay ja Anita Chaumette'i filmi "Räägime kaladega" ("Talking with Fishes") : Suurbritannia 2003

  11. Rein Maran soovitab / Rein Maran

    Index Scriptorium Estoniae

    Maran, Rein, 1931-

    2007-01-01

    Silmas pidades 19. septembril avatavat 5. Matsalu rahvusvahelist loodusfilmide festivali kirjutab autor loodusfilmi rollist ja olemusest ning tutvustab Gay ja Anita Chaumette'i filmi "Räägime kaladega" ("Talking with Fishes") : Suurbritannia 2003

  12. Rein Lang: Eesti kõige väärtuslikum ressurss on mõistus / Rein Lang ; interv. Peep Lillemägi ; komment. Siim Kallas, Jüri Pihl, Väino Linde

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2009-01-01

    Justiitsminister Rein Lang vastab küsimustele, mis puudutavad Ameerika Ühendriike kui vabaduse kantsi, ettevõtlusvabadust Ameerika Ühendriikides ja Eestis, tööd justiitsministrina, varasemat karjääri, Eesti põhiseaduse loomist, Euroopa Liidu aluslepingu välja töötamist, avaliku võimu rolli tänapäeva maailmas ning Eesti jõudmist Euroopa rikkamate riikide hulka

  13. Rein Lang: Eesti kõige väärtuslikum ressurss on mõistus / Rein Lang ; interv. Peep Lillemägi ; komment. Siim Kallas, Jüri Pihl, Väino Linde

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2009-01-01

    Justiitsminister Rein Lang vastab küsimustele, mis puudutavad Ameerika Ühendriike kui vabaduse kantsi, ettevõtlusvabadust Ameerika Ühendriikides ja Eestis, tööd justiitsministrina, varasemat karjääri, Eesti põhiseaduse loomist, Euroopa Liidu aluslepingu välja töötamist, avaliku võimu rolli tänapäeva maailmas ning Eesti jõudmist Euroopa rikkamate riikide hulka

  14. Identifying potential evolutionary relationships within a facultative lycaenid-ant system: Ant association,oviposition, and butterfly-ant conflict

    Institute of Scientific and Technical Information of China (English)

    NEIL COLLIER

    2007-01-01

    Facultative associations are commonly encountered between ants and lycaenids,although the nature and patterns of associations are typically unclear. This study investigated a facultative symbiosis involving the lycaenid Theclinesthes albocincta (Lycaenidae), its host plant Adriana quadripartita and Australian native ants. Ants in the genera Ochetellus and Iridomyrmex were most frequently found in association with T. albocincta larvae,although Iridomyrmex ants were found in much lower abundance than were ants in Ochetellus. The abundances of Ochetellus and Iridomyrmex were highly correlated with larval abundance, but not egg abundance. Observations and experiments recorded oviposition on male inflorescences on more than 95% of occasions, but oviposition was not greater on inflorescences with ants present. Behavioral assays showed that Iridomyrmex ants were aggressive towards female butterflies on significantly more occasions than were Ochetellus ants. These findings indicate potential evolutionary relationships between T. albocincta and two genera of ants that were abundant within the habitat.

  15. Using Ants as bioindicators: Multiscale Issues in Ant Community Ecology

    Directory of Open Access Journals (Sweden)

    Alan Andersen

    1997-06-01

    Full Text Available Ecological patterns and processes are characteristically scale dependent, and research findings often cannot be translated easily from one scale to another. Conservation biology is challenged by a lack of congruence between the spatial scales of ecological research (typically involving small plots and land management (typically involving whole landscapes. Here, I discuss spatial scaling issues as they relate to an understanding of ant communities and, consequently, their use as bioindicators in land management. Our perceptions of fundamental patterns and processes in ant communities depend on scale: taxa that are behaviorally dominant at one scale are not necessarily so at others, functional groups recognized at one scale are often inappropriate for others, and the role of competition in community structure depends on the scale of analysis. Patterns of species richness and composition, and the ability of total richness to be estimated by surrogates, are all also scale dependent. Ant community ecology has a tradition of detailed studies in small plots, but the use of ants as bioindicators requires a predictive understanding of community structure and dynamics at a range of spatial scales. Such an appreciation of ant communities and their most effective use as bioindicators is best served by studies integrating results from plot-scale research with the broad-scale paradigms of biogeography, systematics, and evolutionary biology.

  16. Monoculture of leafcutter ant gardens.

    Directory of Open Access Journals (Sweden)

    Ulrich G Mueller

    Full Text Available BACKGROUND: Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. METHODOLOGY/PRINCIPAL FINDINGS: Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens and extended lifespans (10-20 years. In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells, and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. CONCLUSIONS/SIGNIFICANCE: Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants, an analog of artificial selection.

  17. Macroevolutionary assembly of ant/plant symbioses: Pseudomyrmex ants and their ant-housing plants in the Neotropics.

    Science.gov (United States)

    Chomicki, Guillaume; Ward, Philip S; Renner, Susanne S

    2015-11-22

    Symbioses include some of the clearest cases of coevolution, but their origin, loss or reassembly with different partners can rarely be inferred. Here we use ant/plant symbioses involving three plant clades to investigate the evolution of symbioses. We generated phylogenies for the big-eyed arboreal ants (Pseudomyrmecinae), including 72% of their 286 species, as well as for five of their plant host groups, in each case sampling more than 61% of the species. We show that the ant-housing Vachellia (Mimosoideae) clade and its ants co-diversified for the past 5 Ma, with some species additionally colonized by younger plant-nesting ant species, some parasitic. An apparent co-radiation of ants and Tachigali (Caesalpinioideae) was followed by waves of colonization by the same ant clade, and subsequent occupation by a younger ant group. Wide crown and stem age differences between the ant-housing genus Triplaris (Polygonaceae) and its obligate ant inhabitants, and stochastic trait mapping, indicate that its domatium evolved earlier than the ants now occupying it, suggesting previous symbioses that dissolved. Parasitic ant species evolved from generalists, not from mutualists, and are younger than the mutualistic systems they parasitize. Our study illuminates the macroevolutionary assembly of ant/plant symbioses, which has been highly dynamic, even in very specialized systems. © 2015 The Author(s).

  18. The French Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort study

    Science.gov (United States)

    Stengel, Bénédicte; Combe, Christian; Jacquelinet, Christian; Briançon, Serge; Fouque, Denis; Laville, Maurice; Frimat, Luc; Pascal, Christophe; Herpe, Yves-Edouard; Deleuze, Jean-François; Schanstra, Joost; Pisoni, Ron L.; Robinson, Bruce M.; Massy, Ziad A.

    2014-01-01

    Background While much has been learned about the epidemiology and treatment of end-stage renal disease (ESRD) in the last 30 years, chronic kidney disease (CKD) before the end-stage has been less investigated. Not enough is known about factors associated with CKD progression and complications, as well as its transition to ESRD. We designed the CKD-renal epidemiology and information network (REIN) cohort to provide a research platform to address these key questions and to assess clinical practices and costs in patients with moderate or advanced CKD. Methods A total of 46 clinic sites and 4 renal care networks participate in the cohort. A stratified selection of clinic sites yields a sample that represents a diversity of settings, e.g. geographic region, and public versus for-profit and non-for-profit private clinics. In each site, 60–90 patients with CKD are enrolled at a routine clinic visit during a 12-month enrolment phase: 3600 total, including 1800 with Stage 3 and 1800 with Stage 4 CKD. Follow-up will continue for 5 years, including after initiation of renal replacement therapy. Data will be collected from medical records at inclusion and at yearly intervals, as well as from self-administered patient questionnaires and provider-level questionnaires. Patients will also be interviewed at baseline, and at 1, 3 and 5 years. Healthcare costs will also be determined. Blood and urine samples will be collected and stored for future studies on all patients at enrolment and at study end, and at 1 and 3 years in a subsample of 1200. Conclusions The CKD-REIN cohort will serve to improve our understanding of the biological, clinical and healthcare system determinants associated with CKD progression and adverse outcomes as well as of international variations in collaboration with the CKD Outcome and Practice Pattern Study (CKDopps). It will foster CKD epidemiology and outcomes research and provide evidence to improve the health and quality of life of patients with CKD and

  19. The metapleural gland of ants

    DEFF Research Database (Denmark)

    Yek, Sze Huei; Mueller, Ulrich G

    2011-01-01

    The metapleural gland (MG) is a complex glandular structure unique to ants, suggesting a critical role in their origin and ecological success. We synthesize the current understanding of the adaptive function, morphology, evolutionary history, and chemical properties of the MG. Two functions...... of the MG, sanitation and chemical defence, have received the strongest empirical support; two additional possible functions, recognition odour and territorial marking, are less well supported. The design of the MG is unusual for insects; glandular secretions are stored in a rigid, non...... morphology, phylogenetic transitions and chemical ecology of the MGs of both the derived and the unstudied early-branching (basal) ant lineages is needed to elucidate the evolutionary origin and diversification of the MG of ants....

  20. Ants medicate to fight disease.

    Science.gov (United States)

    Bos, Nick; Sundström, Liselotte; Fuchs, Siiri; Freitak, Dalial

    2015-11-01

    Parasites are ubiquitous, and the ability to defend against these is of paramount importance. One way to fight diseases is self-medication, which occurs when an organism consumes biologically active compounds to clear, inhibit, or alleviate disease symptoms. Here, we show for the first time that ants selectively consume harmful substances (reactive oxygen species, ROS) upon exposure to a fungal pathogen, yet avoid these in the absence of infection. This increased intake of ROS, while harmful to healthy ants, leads to higher survival of exposed ants. The fact that ingestion of this substance carries a fitness cost in the absence of pathogens rules out compensatory diet choice as the mechanism, and provides evidence that social insects medicate themselves against fungal infection, using a substance that carries a fitness cost to uninfected individuals.

  1. A cellular automata model for ant trails

    Indian Academy of Sciences (India)

    Sibel Gokce; Ozhan Kayacan

    2013-05-01

    In this study, the unidirectional ant traffic flow with U-turn in an ant trail was investigated using one-dimensional cellular automata model. It is known that ants communicate with each other by dropping a chemical, called pheromone, on the substrate. Apart from the studies in the literature, it was considered in the model that (i) ant colony consists of two kinds of ants, goodand poor-smelling ants, (ii) ants might make U-turn for some special reasons. For some values of densities of good- and poor-smelling ants, the flux and mean velocity of the colony were studied as a function of density and evaporation rate of pheromone.

  2. Ant opsins: sequences from the Saharan silver ant and the carpenter ant.

    Science.gov (United States)

    Popp, M P; Grisshammer, R; Hargrave, P A; Smith, W C

    1996-03-01

    cDNA clones encoding opsins from compound eyes of carpenter ant, Camponotus abdominalis, and Saharan silver ant, Cataglyphis bombycina, were isolated from cDNA libraries. The opsin cDNAs from each species code for deduced proteins with 378 amino acids which are 92% identical. Of the 30 amino acid differences between the two proteins, 13 are non-conservative. Eight of these non-conservative substitutions are within the membrane spanning domain. The presence of a potential Schiff-base counterion in helix III in both species suggests that these opsins are the protein moiety of the visible range pigments. When compared to all known opsins, these opsins are most similar to the opsin from preying mantis (76% identity at the amino acid level). Phyletic comparisons group the two ant opsins with the other arthropod long wavelength opsins.

  3. Pest repellent properties of ant pheromones

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2012-01-01

    ant species (iii) Azteca instabilis and (iv) Camponotus textor reduce herbivory by flea beetles (Margaridisa sp.), whereas (v) deposits from Solenopsis geminata, did not lead to reduced herbivory. Further evidence for the impact of ant pheromones comes from studies showing that non-herbivorous ant...

  4. Ant colony optimization in continuous problem

    Institute of Scientific and Technical Information of China (English)

    YU Ling; LIU Kang; LI Kaishi

    2007-01-01

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

  5. Using Ants to Investigate the Environment

    Science.gov (United States)

    Hagevik, Rita A.

    2005-01-01

    The best place for students to begin to understand complex environmental relationships is in their own back yards. Doing investigations of ants allows students to establish a baseline survey of ant fauna, test the importance of ants in nutrient cycling and soil structure maintenance, and increase their understanding of the environment and their…

  6. Kas sina julgeksid ennustada tulevikku? / Karolin Kuusik

    Index Scriptorium Estoniae

    Kuusik, Karolin

    2007-01-01

    Filmid ja nende kostüümikunstnikud, kes on mõjutanud rõivamoodi : "Barbarella" (1968), kostüümikunstnikud Jacques Fonteray ja Paco Rabanne; "Blade Runner" (1982), kunstnikud Charles Knode ja Michael Kaplan; "Matrix" ja selle järjed (1999, 2003), kostüümidisainer Kym Barrett; "Star Wars" ja selle järjed (1977, 1980, 1983, 1999, 2002, 2005), kunstnik John Mollo, hiljem Trisha Biggar; "Aeon Flux" (2005), kostüümikunstnik Beatrix Aruna Pasztor

  7. Kas sina julgeksid ennustada tulevikku? / Karolin Kuusik

    Index Scriptorium Estoniae

    Kuusik, Karolin

    2007-01-01

    Filmid ja nende kostüümikunstnikud, kes on mõjutanud rõivamoodi : "Barbarella" (1968), kostüümikunstnikud Jacques Fonteray ja Paco Rabanne; "Blade Runner" (1982), kunstnikud Charles Knode ja Michael Kaplan; "Matrix" ja selle järjed (1999, 2003), kostüümidisainer Kym Barrett; "Star Wars" ja selle järjed (1977, 1980, 1983, 1999, 2002, 2005), kunstnik John Mollo, hiljem Trisha Biggar; "Aeon Flux" (2005), kostüümikunstnik Beatrix Aruna Pasztor

  8. Male parentage in army ants

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; Schöning, Caspar; Boomsma, Jacobus J

    2006-01-01

    of active research in insect sociobiology. Here we present microsatellite data for 176 males from eight colonies of the African army ant Dorylus (Anomma) molestus. Comparison with worker genotypes and inferred queen genotypes from the same colonies show that workers do not or at best very rarely reproduce...

  9. Optimal cue integration in ants.

    Science.gov (United States)

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-10-07

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy. © 2015 The Author(s).

  10. The antipredatory behaviours of Neotropical ants towards army ant raids (Hymenoptera : Formicidae)

    OpenAIRE

    Dejean, A.; Corbara, B.; Roux, Olivier; Orivel, J.

    2014-01-01

    Group hunting, nomadism, wingless queens and colony fission characterize army ants, allowing them to have become the main tropical arthropod predators, mostly of other social insects. We studied the reactions of different ant species to the New World army ants Eciton burchellii (WESTWOOD, 1842) and E. hamatum (FABRICUS, 1782) (Ecitoninae). We compiled our results with those already known in a synthetic appendix. A wide range of ant species react to the approach of army ant raids by evacuating...

  11. Une reine entre ombres et lumières ou le pouvoir au féminin : le cas d’Isabelle Bourbon, reine d’Espagne, première femme de Philippe IV (1603-1644

    Directory of Open Access Journals (Sweden)

    Frédérique Sicard

    2009-09-01

    Full Text Available Le rôle de la Reine et sa relation au pouvoir sont strictement réglementés, mais son influence politique est paradoxalement difficile à apprécier car elle s’exerce à l’ombre de ce qui est permis. Isabelle de Bourbon, née Princesse de France, épouse en 1615 le Prince héritier Philippe d’Espagne et fait partie de ces Reines de l’ombre, peu étudiées. Elevée dans une certaine liberté, le contraste avec la cour d’Espagne et la surveillance de l’omniprésent Favori, le Comte-Duc d’Olivares, lui pèsent d’autant plus. Quel éclairage le cas de la Reine Isabelle permet-il d’apporter à la relation entre genre et pouvoir au Siècle d’Or ? Trois points seront abordés : les tensions et dominations qui se jouent autour du Roi Philippe IV, le poids de la famille, au sens large, indissociable des relations entretenues entre genre et pouvoir. Enfin, nous nous intéresserons à l’activité politique de la Reine Isabelle.The role of French queens and their relation to power were strictly regulated, but their political influence is difficult to assess given the shadows within which they worked. In 1615, Isabelle of Bourbon, born Princess of France, married Philip of Spain and became one of these seldom-studied Queens of the shadows. What illumination does Queen Isabelle’s case bring to the gender-power relationship during the Golden Age? Three points are addressed in the article: the tensions and power dynamics around Philip IV; the weight of the family, in a broad sense, which necessarily affected relations between gender and power. Finally, we will focus on the political activity of Queen Isabelle; her example constitutes a concrete example of women’s power in the Golden Age.

  12. Evolutional Ant Colony Method Using PSO

    Science.gov (United States)

    Morii, Nobuto; Aiyoshi, Eitarou

    The ant colony method is one of heuristic methods capable of solving the traveling salesman problem (TSP), in which a good tour is generated by the artificial ant's probabilistic behavior. However, the generated tour length depends on the parameter describing the ant's behavior, and the best parameters corresponding to the problem to be solved is unknown. In this technical note, the evolutional strategy is presented to find the best parameter of the ant colony by using Particle Swarm Optimization (PSO) in the parameter space. Numerical simulations for benchmarks demonstrate effectiveness of the evolutional ant colony method.

  13. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants.......We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...

  14. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants.......We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...

  15. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  16. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  17. [Data collection about the case management of end-stage renal insufficiency. Feasibility study. Nephrology Epidemiologic and information Network (REIN)].

    Science.gov (United States)

    Stengel, B; Landais, P

    1999-01-01

    End-stage renal failure (ESRD) is an important public health issue, because of both the increasing number of patients requiring renal replacement therapy and the cost of treatment. The need for a reliable data system, capable of describing the patient care network as a whole, including dialysis or transplantation, has often been reiterated. The Direction Générale de la Santé (the French Department of Health) commissioned INSERM (the National Institute of Health and Medical Research) to "study the feasibility of different scenarios of data collection about ESRD patient care in order to meet the priority needs of health care administration, physicians, and researchers". Analysis of these needs allowed the goals to be defined: to provide an accurate picture of ESRD patient care in order to guide and evaluate health care policy, to inform clinicians, and to provide a tool for more focused special studies in renal research issues. Three scenarios were studied: the first would use data systems of both the government and the National Health Insurance system for planning health care services, upon EfG (The French Transplant Agency) network to evaluate transplantation, and upon a few regional registries for epidemiology and research; the second is based on repeated cross-sectional surveys; the third would rely upon the organization of an information system, the Renal Epidemiology and Information Network (REIN). Regional centers and a national coordinating office would register and follow-up ESRD patients, principally to evaluate health care supply and quality. The REIN database would also be a resource for research. The advantage of the first scenario is its low cost; its principal drawback is that evaluations will not be possible in the regions without registries. The second suggestion is inadequate. The last project would fulfil the goals that were defined. The REIN data system would be a true public health project of interest to all the participants and institutions

  18. Introduced fire ants can exclude native ants from critical mutualist-provided resources.

    Science.gov (United States)

    Wilder, Shawn M; Barnum, Thomas R; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

    2013-05-01

    Animals frequently experience resource imbalances in nature. For ants, one resource that may be particularly valuable for both introduced and native species is high-carbohydrate honeydew from hemipteran mutualists. We conducted field and laboratory experiments: (1) to test if red imported fire ants (Solenopsis invicta) competed with native ants for access to mutualisms with aphids, and (2) to quantify the effects of aphid honeydew presence or absence on colony growth of native ants. We focused on native dolichoderine ants (Formicidae, Dolichoderinae) because they are abundant ants that have omnivorous diets that frequently include mutualist-provided carbohydrates. At two sites in the southeastern US, native dolichoderine ants were far less frequent, and fire ants more frequent, at carbohydrate baits than would be expected based on their frequency in pitfall traps. A field experiment confirmed that a native ant species, Dorymyrmex bureni, was only found tending aphids when populations of S. invicta were suppressed. In the laboratory, colonies of native dolichoderine ants with access to both honeydew and insect prey had twice as many workers and over twice as much brood compared to colonies fed only ad libitum insect prey. Our results provide the first experimental evidence that introduced ants compete for access to mutualist-provided carbohydrates with native ants and that these carbohydrates represent critical resources for both introduced and native ants. These results challenge traditional paradigms of arthropod and ant nutrition and contribute to growing evidence of the importance of nutrition in mediating ecological interactions.

  19. Team swimming in ant spermatozoa.

    Science.gov (United States)

    Pearcy, Morgan; Delescaille, Noémie; Lybaert, Pascale; Aron, Serge

    2014-06-01

    In species where females mate promiscuously, competition between ejaculates from different males to fertilize the ova is an important selective force shaping many aspects of male reproductive traits, such as sperm number, sperm length and sperm-sperm interactions. In eusocial Hymenoptera (bees, wasps and ants), males die shortly after mating and their reproductive success is ultimately limited by the amount of sperm stored in the queen's spermatheca. Multiple mating by queens is expected to impose intense selective pressure on males to optimize the transfer of sperm to the storage organ. Here, we report a remarkable case of cooperation between spermatozoa in the desert ant Cataglyphis savignyi. Males ejaculate bundles of 50-100 spermatozoa. Sperm bundles swim on average 51% faster than solitary sperm cells. Team swimming is expected to increase the amount of sperm stored in the queen spermatheca and, ultimately, enhance male posthumous fitness.

  20. Workload and stress in horses: comparison in horses ridden deep and round ('rollkur') with a draw rein and horses ridden in a natural frame with only light rein contact.

    Science.gov (United States)

    Sloet van Oldruitenborgh-Oosterbaan, M M; Blok, M B; Begeman, L; Kamphuis, M C D; Lameris, M C; Spierenburg, A J; Lashley, M J J O

    2006-03-01

    'Rollkur' or 'overbending' is the low and deep riding of a dressage horse during training or warming up. Lately, this technique has been criticized, and not necessarily objectively, on welfare grounds. To be able to evaluate these criticisms, more needs to be known about the workload and stress of horses being ridden 'rollkur'. The aim of the present study was to compare the workload of eight riding-school horses when being ridden deep and round with a draw rein ('rollkur') and when being ridden in a natural frame with only light rein contact ('free'). Workload (as measured by heart rate and blood lactate concentration) was slightly higher when horses were ridden 'rollkur' than when they were ridden 'free'. There were no differences in packed cell volume, or glucose and cortisol concentrations. No signs of uneasiness or stress could be determined when the horses were ridden 'rollkur'. Subjectively, all horses improved their way of moving during 'rollkur' and were more responsive to their rider.

  1. Ecosystem services delivered by weaver ants

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from the pres......Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from...... the presence of these ants. First of all, the chemical footprint left by the high density of ants in managed host trees may results in additional benefits. (i) Ant deposits may lead to improved fruit quality, e.g. increased sugar content, (ii) ant deposits may deter important pests (chemical deterrence) from...... crops, and lastly, (iii) ant waste products deposited ias anal spots contain urea that may be taken up by plant leaves and in this way fertilize ant-plants. On top of chemical services, weaver ants have been shown to reduce plant disease incidence via competitive exclusion of other ant species because...

  2. The distribution and diversity of insular ants

    DEFF Research Database (Denmark)

    Roura-Pascual, Núria; Sanders, Nate; Hui, Cang

    2016-01-01

    Aim: To examine the relationship between island characteristics (area, distance to the nearest continent, climate and human population size) and ant species richness, as well as the factors underlying global geographical clustering of native and exotic ant composition on islands. Location: One...... hundred and two islands from 20 island groups around the world. Methods: We used spatial linear models that consider the spatial structure of islands to examine patterns of ant species richness. We also performed modularity analyses to identify clusters of islands hosting a similar suite of species...... and constructed conditional inference trees to assess the characteristics of islands that explain the formation of these island-ant groups. Results: Island area was the best predictor of ant species richness. However, distance to the nearest continent was an important predictor of native ant species richness...

  3. Ecosystem services delivered by weaver ants

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from the pres......Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from...... crops, and lastly, (iii) ant waste products deposited ias anal spots contain urea that may be taken up by plant leaves and in this way fertilize ant-plants. On top of chemical services, weaver ants have been shown to reduce plant disease incidence via competitive exclusion of other ant species because...

  4. Bio-inspired Ant Algorithms: A review

    Directory of Open Access Journals (Sweden)

    Sangita Roy

    2013-05-01

    Full Text Available Ant Algorithms are techniques for optimizing which were coined in the early 1990’s by M. Dorigo. The techniques were inspired by the foraging behavior of real ants in the nature. The focus of ant algorithms is to find approximate optimized problem solutions using artificial ants and their indirect decentralized communications using synthetic pheromones. In this paper, at first ant algorithms are described in details, then transforms to computational optimization techniques: the ACO metaheuristics and developed ACO algorithms. A comparative study of ant algorithms also carried out, followed by past and present trends in AAs applications. Future prospect in AAs also covered in this paper. Finally a comparison between AAs with well-established machine learning techniques were focused, so that combining with machine learning techniques hybrid, robust, novel algorithms could be produces for outstanding result in future.

  5. Ants as tools in sustainable agriculture

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2015-01-01

    1. With an expanding human population placing increasing pressure on the environment, agriculture needs sustainable production that can match conventional methods. Integrated pest management (IPM) is more sustainable, but not necessarily as efficient as conventional non-sustainable measures. 2....... Being predatory and organized as superorganisms, ants possess traits making them suitable agents in IPM. Recent works on weaver ants Oecophylla spp. showcase ants as highly efficient pest controllers. A synthesis shows that weaver ants can reduce pest numbers and their damage and increase yields...... in multiple crops. Their efficiency is comparable to chemical pesticides or higher, while at lower costs. They provide a rare example of documented efficient conservation biological control. 3. Weaver ants share beneficial traits with almost 13 000 other ant species and are unlikely to be unique...

  6. Foliar uptake of nitrogen from ant fecal droplets: an overlooked service to ant plants

    DEFF Research Database (Denmark)

    Pinkalski, Christian Alexander Stidsen; Jensen, Karl-Martin Vagn; Damgaard, Christian Frølund

    2017-01-01

    facultative relationships, where ants forage on plants. 2. In a laboratory setupexperiment, weaver ants (Oecophylla smaragdina) were confined to the canopies of coffee (Coffea arabica) seedlings, excluding any ant-to-plant transfer of nutrients via the soil strata. When ants were fed 15N-labelled glycine......-recognised but probably more fluctuating benefit from herbivore protection. Given the worldwide abundance of plant canopies foraged by ants, this nutrient pathway may be of high ecological significance.......1. Nutrient supplies to plants from ants are well known from specialised myrmecophytic symbioses and from plants growing in soil close to ant nests. However, above ground nutrient pathways may play a hitherto largely unrecognised role also in less specialised ant-plant interactions – the numerous...

  7. The essential of 2012 results from the French Renal Epidemiology and Information Network (REIN) ESRD registry.

    Science.gov (United States)

    Lassalle, Mathilde; Ayav, Carole; Frimat, Luc; Jacquelinet, Christian; Couchoud, Cécile

    2015-04-01

    The French Renal Epidemiology and Information Network (REIN) registry began in 2002 to provide a tool for public health decision support, evaluation and research related to renal replacement therapies (RRT) for end-stage renal disease (ESRD). It is relying on a network of nephrologists, epidemiologists, patients and public health representatives. Continuous registration covers all dialysis and transplanted patients. In 2012, in France, 10,048 patients started a RRT (154 per million inhabitants). Elders provided majority of new patients (median age at RRT start: 70 years old). New patients had a high and age increasing rate of comorbidities, especially diabetes (42% of the new patients) and cardiovascular comorbidities (>50% of the new patients). Like previous years, incidence is stabilized. On December 31, 2012, 73,491 patients were receiving a RRT in France (1127 per million inhabitants, 56% on dialysis and 44% living with a functional renal transplant). More than 50% of patients were undergoing in-center hemodialysis with significant variations among regions. An increase in medical satellite unit hemodialysis but a decrease in self-care unit hemodialysis rates were noticed across the time, whereas peritoneal dialysis remained stable at 7%. Five years after starting RRT, the overall survival rate was 51% but only 16% among patients over 85 years. Mortality rate was highly dependent on treatment and age; transplanted patients aged 60-69 had a 27/1000 patients-year mortality rate versus 133 for a dialysis patient. Patients who started dialysis had a probability of first wait-listing of 4.8% at the start of dialysis (pre-emptive registrations) and 27% at 72 months. Whatever their diabetes status was, patients older than 60 had poor access to the waiting list. Seventeen percent of the patients received a first renal transplant within 15.4 month median time; 3% had received a pre-emptive graft. Ten years after the start of the French ESRD registry, this report provides

  8. Fr. R. Kreutzwalds "Kalevipoeg" als ein Heiliger Text der estnischen literarischen Kultur : eine literaturkritische Studie / Rein Veidemann ; Übersetzung: Ilse Freymann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2004-01-01

    Eesti keeles ilmunud: Keel ja Kirjandus, 2003, nr. 12; Vene k.: "Kalevipoeg" kak sakralnõi tekst estonskoi kultyrõ / tlk. Marina Tervonen // Veidemann, Rein. Kollokvium po estonskoi literatute. Tallinn : Izd. "KPD", 2007, lk. 5-13. Orig.: Fr. R. Kreutzwaldi "Kalevipoeg" kui eesti kirjanduskultuuri sakraaltekst

  9. Maksud on pööraselt oluline küsimus, mis pole Eestis lõpuni vaieldud / Rein Lang ; interv. Koit Luus

    Index Scriptorium Estoniae

    Lang, Rein, 1957-

    2005-01-01

    Välisminister selgitab oma suhtumist talle omistatud meediavaenulikuma isiku tiitlisse, arutleb poliitilise eliidi vastutuse teemal, annab hinnangu Eesti maksusüsteemile, mõtiskleb tagasivaatavalt oma karjäärist, põhjendab reformide vajalikkust hariduses ja tervishoiusüsteemis ning suhtub kriitiliselt Jüri Lina seisukohtadesse. Kommenteerivad Toomas Alatalu, Meelis Atonen. Lisa: Rein Lang

  10. Fr. R. Kreutzwalds "Kalevipoeg" als ein Heiliger Text der estnischen literarischen Kultur : eine literaturkritische Studie / Rein Veidemann ; Übersetzung: Ilse Freymann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2004-01-01

    Eesti keeles ilmunud: Keel ja Kirjandus, 2003, nr. 12; Vene k.: "Kalevipoeg" kak sakralnõi tekst estonskoi kultyrõ / tlk. Marina Tervonen // Veidemann, Rein. Kollokvium po estonskoi literatute. Tallinn : Izd. "KPD", 2007, lk. 5-13. Orig.: Fr. R. Kreutzwaldi "Kalevipoeg" kui eesti kirjanduskultuuri sakraaltekst

  11. Rein Kilk lõi bürokraatia võrgus siplevale Vene laevaliinile käega / Nils Niitra

    Index Scriptorium Estoniae

    Niitra, Nils, 1975-

    2004-01-01

    Ilmunud ka: Postimees, 16. apr. 2004, lk. 4. Ärimees Rein Kilgi tegevusest Tartu-Pihkva laevaliini avamiseks. Vene võimude suutmatuse tõttu kokku leppida Starozhinetsi sadama tolli- ja piiripunkti sisustamises loobus Tartu ärimees ettevõtmisest

  12. Kust tulevad eestlased : eestlaste väikse sündimuse põhjuseks on lasterikaste perede madal maine / Avo-Rein Tereping

    Index Scriptorium Estoniae

    Tereping, Avo-Rein, 1945-

    2011-01-01

    Tallinna Ülikooli psühholoogiaõppejõud Avo-Rein Tereping tõdeb, et lasterikkust tuleb väärtustada. Mitte ainult materiaalsete vahenditega, vaid vaja on kasutada ka teisi hoobasid. President võiks eeskuju anda regulaarsete külaskäikudega lasterikastesse peredesse

  13. Valitsusliidu programmi eelnõu: arendada, parendada, analüüsida / Rando Tooming, Margo Pajuste ; kommenteerinud Aivar Haller, Artur Talvik, Rainer Kattel, Eiki Nestor, Rein Raud

    Index Scriptorium Estoniae

    Tooming, Rando

    2011-01-01

    Olulisemad lubadused Reformierakonna ja Isamaa ja Res Publica valitsusliidu programmi eelnõust. Uue koalitsioonileppe kohta avaldavad arvamust Eesti Lastevanemate Liidu juhatuse liige Aivar Haller, Roheliste erakonnas kandideerinud Artur Talvik, TTÜ professor Rainer Kattel, Sotsiaaldemokraatliku Erakonna liige Eiki Nestor ja Tallinna Ülikooli rektor Rein Raud

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

    OpenAIRE

    Liqiang Liu; Yuntao Dai; Jinyu Gao

    2014-01-01

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

  15. Microorganisms transported by ants induce changes in floral nectar composition of an ant-pollinated plant.

    Science.gov (United States)

    de Vega, Clara; Herrera, Carlos M

    2013-04-01

    Interactions between plants and ants abound in nature and have significant consequences for ecosystem functioning. Recently, it has been suggested that nectar-foraging ants transport microorganisms to flowers; more specifically, they transport yeasts, which can potentially consume sugars and alter nectar composition. Therefore, ants could indirectly change nectar sugar profile, an important floral feature involved in the plant-pollinator mutualism. But this novel role for ants has never been tested. We here investigate the effects of nectarivorous ants and their associated yeasts on the floral nectar sugar composition of an ant-pollinated plant. Differences in the nectar sugar composition of ant-excluded and ant-visited flowers were examined in 278 samples by using high-performance liquid-chromatography. The importance of the genetic identity and density of ant-transported basidiomycetous and ascomycetous yeasts on the variation of nectar traits was also evaluated. Ant visitation had significant effects on nectar sugar composition. The nectar of ant-visited flowers contained significantly more fructose, more glucose, and less sucrose than the nectar of ant-excluded flowers, but these effects were context dependent. Nectar changes were correlated with the density of yeast cells in nectar. The magnitude of the effects of ant-transported ascomycetes was much higher than that of basiodiomycetes. Ants and their associated yeasts induce changes in nectar sugar traits, reducing the chemical control of the plant over this important floral trait. The potential relevance of this new role for ants as indirect nectar modifiers is a rich topic for future research into the ecology of ant-flower interactions.

  16. Fungal Adaptations to Mutualistic Life with Ants

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus

    that forage on crude substrates such as insect frass and dry plant material, to large colonies of the leaf-cutting ants with several thousands to several million workers that provide live plant material to their fungus gardens. Leaf-cutting ants are the dominant herbivores of the Neo-tropics, and have a major...... on specific enzyme groups and Acromyrmex having an overall high enzyme activity. Finally, I show that the fungal symbiont of the leaf-cutting ant Acromyrmex echinatior produces large amounts of biodegrading enzymes in special structures called gongylidia. The ants eat these structures, but enzymes pass...

  17. GRID SCHEDULING USING ENHANCED ANT COLONY ALGORITHM

    Directory of Open Access Journals (Sweden)

    P. Mathiyalagan

    2010-10-01

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

  18. From Ant Trails to Pedestrian Dynamics

    Directory of Open Access Journals (Sweden)

    Andreas Schadschneider

    2003-01-01

    Full Text Available This paper presents a model for the simulation of pedestrian dynamics inspired by the behaviour of ants in ant trails. Ants communicate by producing a pheromone that can be smelled by other ants. In this model, pedestrians produce a virtual pheromone that influences the motion of others. In this way all interactions are strictly local, and so even large crowds can be simulated very efficiently. Nevertheless, the model is able to reproduce the collective effects observed empirically, eg the formation of lanes in counterflow. As an application, we reproduce a surprising result found in experiments of evacuation from an aircraft.

  19. Ilmub suurmeister Evald Okase monograafia / Ants Juske

    Index Scriptorium Estoniae

    Juske, Ants, 1956-

    2009-01-01

    22. aprillil Kumu Kunstimuuseumis esitletavast monograafiast "Evald Okas", mille on kirjutanud Ants Juske, kujundanud Tiit Jürna. Evald Okasest, tema loomingust, elust Jaroslavlis ja rindekunstnikuna

  20. Enhanced ants system and its application

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    NP-hard combinational optimization problem is not solved very well until now. One enhanced ants system based on ants system is advanced after analysis of the deficiencies of existing ants systems. Some improvements are made in state transfer rule and local modification rule. Furthermore, the enhanced ants system can solve NP-hard combinational optimization problem with restraints and condition path. The successful application of TSP problem and transportation net problem indicates that the proposed system has stronger function and higher efficiency than the original system.

  1. Conflict resolution in an ant-plant interaction: Acacia constricta traits reduce ant costs to reproduction.

    Science.gov (United States)

    Nicklen, E Fleur; Wagner, Diane

    2006-05-01

    Many plant species attract ants onto their foliage with food rewards or nesting space. However, ants can interfere with plant reproduction when they visit flowers. This study tests whether Acacia constricta separates visiting ant species temporally or spatially from newly opened inflorescences and pollinators. The diurnal activity patterns of ants and A. constricta pollinators peaked at different times of day, and the activity of pollinators followed the daily dehiscence of A. constricta inflorescences. In addition to being largely temporally separated, ants rarely visited open inflorescences. A floral ant repellent contributes to the spatial separation of ants and inflorescences. In a field experiment, ants of four species were given equal access to inflorescences in different developmental stages. On average, the frequency with which ants made initial, antennal contact with the floral stages did not differ, but ants significantly avoided secondary contact with newly opened inflorescences relative to buds and old inflorescences, and old inflorescences relative to buds. Ants also avoided contact with pollen alone, indicating that pollen is at least one source of the repellent. The results suggest A. constricta has effectively resolved the potential conflict between visiting ants and plant reproduction.

  2. Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles

    Science.gov (United States)

    Zettler, Jennifer A.; Collier, Alexander; Leidersdorf, Bil; Sanou, Missa Patrick

    2010-01-01

    Urban students often have limited access to field sites for ecological studies. Ubiquitous ants and their mounds can be used to study and test ecology-based questions. We describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

  3. Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles

    Science.gov (United States)

    Zettler, Jennifer A.; Collier, Alexander; Leidersdorf, Bil; Sanou, Missa Patrick

    2010-01-01

    Urban students often have limited access to field sites for ecological studies. Ubiquitous ants and their mounds can be used to study and test ecology-based questions. We describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

  4. The evolution of genome size in ants

    Directory of Open Access Journals (Sweden)

    Spagna Joseph C

    2008-02-01

    Full Text Available Abstract Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta, and the two published estimates for this species differ by 146.7 Mb (0.15 pg. Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile, Neotropical army ants (genera Eciton and Labidus, trapjaw ants (Odontomachus, fungus-growing ants (Apterostigma, Atta and Sericomyrmex, harvester ants (Messor, Pheidole and Pogonomyrmex, carpenter ants (Camponotus, a fire ant (Solenopsis, and a bulldog ant (Myrmecia. Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may

  5. Spectacular Batesian mimicry in ants

    Science.gov (United States)

    Ito, Fuminori; Hashim, Rosli; Huei, Yek Sze; Kaufmann, Eva; Akino, Toshiharu; Billen, Johan

    2004-10-01

    The mechanism by which palatable species take advantage of their similarity in appearance to those that are unpalatable, in order to avoid predation, is called Batesian mimicry. Several arthropods are thought to be Batesian mimics of social insects; however, social insects that are Batesian mimics among themselves are rare. In Malaysia we found a possible Batesian mimic in an arboreal ant species, Camponotus sp., which was exclusively observed on foraging trails of the myrmicine ant Crematogaster inflata. The bright yellow and black colouring pattern, as well as the walking behaviour, were very similar in both species. We observed general interactions between the two species, and tested their palatability and the significance of the remarkably similar visual colour patterns for predator avoidance. Prey offered to C. inflata was also eaten by Camponotus workers in spite of their being attacked by C. inflata, indicating that Camponotus sp. is a commensal of C. inflata. An experiment with chicks as potential predators suggests that Camponotus sp. is palatable whereas C. inflata is unpalatable. After tasting C. inflata, the chicks no longer attacked Camponotus sp., indicating that Camponotus sp. is a Batesian mimic of Crematogaster inflata.

  6. Antthrushes, antpittas, and gnateaters (Aves, Formicariidae) as army ant followers

    OpenAIRE

    Edwin O. Willis

    1984-01-01

    Antthrushes (Formicarius, Chamaeza) sometimes walk around swarms of army ants and capture ground prey, but do not follow ants regularly. Among antpittas, only fast-leaping Pittasoma michleri and P. rufopileatum regularly follow ants. Gnateaters (Conopophaga) follow ants little. All these ground-foraging genera are poorly adapted for rapid flying, and failure to follow ants is perhaps due to inability to evade predators or out fly competitors near groups of birds attracted by ants.

  7. Fire Evacuation using Ant Colony Optimization Algorithm

    National Research Council Canada - National Science Library

    Kanika Singhal; Shashank Sahu

    2016-01-01

    ... planning.The objective of the algorithm is to minimizes the entire rescue time of all evacuees.The ant colony optimization algorithm is used to solve the complications of shortest route planning. Presented paper gives a comparative overview of various emergency scenarios using ant colony optimization algorithm.

  8. Extrafloral nectar fuels ant life in deserts.

    Science.gov (United States)

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-11-07

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant-plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities. Published by Oxford University Press on behalf of the Annals of Botany Company.

  9. The Biochemical Toxin Arsenal from Ant Venoms.

    Science.gov (United States)

    Touchard, Axel; Aili, Samira R; Fox, Eduardo Gonçalves Paterson; Escoubas, Pierre; Orivel, Jérôme; Nicholson, Graham M; Dejean, Alain

    2016-01-20

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents.

  10. Dynamical Equilibrium of Interacting Ant Societies

    CERN Document Server

    Leok, B T M

    1996-01-01

    The sustainable biodiversity associated with a specific ecological niche as a function of land area is analysed computationally by considering the interaction of ant societies over a collection of islands. A power law relationship between sustainable species and land area is observed. We will further consider the effect a perturbative inflow of ants has upon the model.

  11. Neuropeptidomics of the carpenter ant Camponotus floridanus.

    Science.gov (United States)

    Schmitt, Franziska; Vanselow, Jens T; Schlosser, Andreas; Kahnt, Jörg; Rössler, Wolfgang; Wegener, Christian

    2015-03-01

    Ants show a rich behavioral repertoire and a highly complex organization, which have been attracting behavioral and sociobiological researchers for a long time. The neuronal underpinnings of ant behavior and social organization are, however, much less understood. Neuropeptides are key signals that orchestrate animal behavior and physiology, and it is thus feasible to assume that they play an important role also for the social constitution of ants. Despite the availability of different ant genomes and in silico prediction of ant neuropeptides, a comprehensive biochemical survey of the neuropeptidergic communication possibilities of ants is missing. We therefore combined different mass spectrometric methods to characterize the neuropeptidome of the adult carpenter ant Camponotus floridanus. We also characterized the local neuropeptide complement in different parts of the nervous and neuroendocrine system, including the antennal and optic lobes. Our analysis identifies 39 neuropeptides encoded by different prepropeptide genes, and in silico predicts new prepropeptide genes encoding CAPA peptides, CNMamide as well as homologues of the honey bee IDLSRFYGHFNT- and ITGQGNRIF-containing peptides. Our data provides basic information about the identity and localization of neuropeptides that is required to anatomically and functionally address the role and significance of neuropeptides in ant behavior and physiology.

  12. Ants, rodents and seed predation in Proteaceae

    African Journals Online (AJOL)

    Ants may reduce seed predation by rapidly transporting and burying seeds in their .... the size and shape of inverted waste paper baskets or b) by securing a lid 5 ... Mimetes experiment was dry for only 3 h before rain set in. Ant activity ceased ...

  13. The Biochemical Toxin Arsenal from Ant Venoms

    Directory of Open Access Journals (Sweden)

    Axel Touchard

    2016-01-01

    Full Text Available Ants (Formicidae represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents.

  14. Open Problem: Analyzing Ant Robot Coverage

    Science.gov (United States)

    2010-01-01

    Efficient and inefficient ant coverage methods. Annals of Mathematics and Artificial Intelligence, 31, 41–76. The proofs can be found in the technical...Wagner, I., & Bruckstein, A. (2001). Special issue on ant robotics. Annals of Mathematics and Artificial Intelligence, 31. Wagner, I., Lindenbaum, M

  15. Ant aggression and evolutionary stability in plant-ant and plant-pollinator mutualistic interactions.

    Science.gov (United States)

    Oña, L; Lachmann, M

    2011-03-01

    Mutualistic partners derive a benefit from their interaction, but this benefit can come at a cost. This is the case for plant-ant and plant-pollinator mutualistic associations. In exchange for protection from herbivores provided by the resident ants, plants supply various kinds of resources or nests to the ants. Most ant-myrmecophyte mutualisms are horizontally transmitted, and therefore, partners share an interest in growth but not in reproduction. This lack of alignment in fitness interests between plants and ants drives a conflict between them: ants can attack pollinators that cross-fertilize the host plants. Using a mathematical model, we define a threshold in ant aggressiveness determining pollinator survival or elimination on the host plant. In our model we observed that, all else being equal, facultative interactions result in pollinator extinction for lower levels of ant aggressiveness than obligatory interactions. We propose that the capacity to discriminate pollinators from herbivores should not often evolve in ants, and when it does it will be when the plants exhibit limited dispersal in an environment that is not seed saturated so that each seed produced can effectively generate a new offspring or if ants acquire an extra benefit from pollination (e.g. if ants eat fruit). We suggest specific mutualism examples where these hypotheses can be tested empirically. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  16. AntStar: Enhancing Optimization Problems by Integrating an Ant System and A⁎ Algorithm

    Directory of Open Access Journals (Sweden)

    Mohammed Faisal

    2016-01-01

    Full Text Available Recently, nature-inspired techniques have become valuable to many intelligent systems in different fields of technology and science. Among these techniques, Ant Systems (AS have become a valuable technique for intelligent systems in different fields. AS is a computational system inspired by the foraging behavior of ants and intended to solve practical optimization problems. In this paper, we introduce the AntStar algorithm, which is swarm intelligence based. AntStar enhances the optimization and performance of an AS by integrating the AS and A⁎ algorithm. Applying the AntStar algorithm to the single-source shortest-path problem has been done to ensure the efficiency of the proposed AntStar algorithm. The experimental result of the proposed algorithm illustrated the robustness and accuracy of the AntStar algorithm.

  17. Persistence of pollination mutualisms in the presence of ants.

    Science.gov (United States)

    Wang, Yuanshi; Wang, Shikun

    2015-01-01

    This paper considers plant-pollinator-ant systems in which the plant-pollinator interaction is mutualistic but ants have both positive and negative effects on plants. The ants also interfere with pollinators by preventing them from accessing plants. While a Beddington-DeAngelis (BD) formula can describe the plant-pollinator interaction, the formula is extended in this paper to characterize the pollination mutualism under the ant interference. Then, a plant-pollinator-ant system with the extended BD functional response is discussed, and global dynamics of the model demonstrate the mechanisms by which pollination mutualism can persist in the presence of ants. When the ant interference is strong, it can result in extinction of pollinators. Moreover, if the ants depend on pollination mutualism for survival, the strong interference could drive pollinators into extinction, which consequently lead to extinction of the ants themselves. When the ant interference is weak, a cooperation between plant-ant and plant-pollinator mutualisms could occur, which promotes survival of both ants and pollinators, especially in the case that ants (respectively, pollinators) cannot survive in the absence of pollinators (respectively, ants). Even when the level of ant interference remains invariant, varying ants' negative effect on plants can result in survival/extinction of both ants and pollinators. Therefore, our results provide an explanation for the persistence of pollination mutualism when there exist ants.

  18. Modified chaotic ant swarm to function optimization

    Institute of Scientific and Technical Information of China (English)

    LI Yu-ying; WEN Qiao-yan; LI Li-xiang

    2009-01-01

    The chaotic ant swarm algorithm (CAS) is an optimization algorithm based on swarm intelligence theory, and it is inspired by the chaotic and self-organizing behavior of the ants in nature. Based on the analysis of the properties of the CAS, this article proposes a variation on the CAS called the modified chaotic ant swarm (MCAS), which employs two novel strategies to significantly improve the performance of the original algorithm. This is achieved by restricting the variables to search ranges and making the global best ant to learn from different ants' best information in the end. The simulation of the MCAS on five benchmark functions shows that the MCAS improves the precision of the solution.

  19. Microclimatic conditions of Lasius flavus ant mounds

    Science.gov (United States)

    Véle, Adam; Holuša, Jaroslav

    2017-05-01

    Like other organisms, ants require suitable microclimatic conditions for their development. Thus, ant species inhabiting colder climates build nest mounds that rise above the soil surface, presumably to obtain heating from solar radiation. Although some ant species construct mounds of organic materials, which generate substantial heat due to microbial metabolism, Lasius flavus mounds consists mostly of soil, not organic material. The use of artificial shading in the current study demonstrated that L. flavus depends on direct solar radiation to regulate the temperature in its mound-like nests. Temperatures were much lower in shaded mounds than in unshaded mounds and were likely low enough in shaded mounds to reduce ant development and reproduction. In areas where L. flavus and similar ants are undesirable, they might be managed by shading.

  20. Uncovering the complexity of ant foraging trails.

    Science.gov (United States)

    Czaczkes, Tomer J; Grüter, Christoph; Jones, Sam M; Ratnieks, Francis L W

    2012-01-01

    The common garden ant Lasius niger use both trail pheromones and memory of past visits to navigate to and from food sources. In a recent paper we demonstrated a synergistic effect between route memory and trail pheromones: the presence of trail pheromones results in experienced ants walking straighter and faster. We also found that experienced ants leaving a pheromone trail deposit less pheromone. Here we focus on another finding of the experiment: the presence of cuticular hydrocarbons (CHCs), which are used as home range markers by ants, also affects pheromone deposition behavior. When walking on a trail on which CHCs are present but trail pheromones are not, experienced foragers deposit less pheromone on the outward journey than on the return journey. The regulatory mechanisms ants use during foraging and recruitment behavior is subtle and complex, affected by multiple interacting factors such as route memory, travel direction and the presence trail pheromone and home-range markings.

  1. Spatiotemporal chemotactic model for ant foraging

    Science.gov (United States)

    Ramakrishnan, Subramanian; Laurent, Thomas; Kumar, Manish; Bertozzi, Andrea L.

    2014-12-01

    In this paper, we present a generic theoretical chemotactic model that accounts for certain emergent behaviors observed in ant foraging. The model does not have many of the constraints and limitations of existing models for ants colony dynamics and takes into account the distinctly different behaviors exhibited in nature by ant foragers in search of food and food ferrying ants. Numerical simulations based on the model show trail formation in foraging ant colonies to be an emergent phenomenon and, in particular, replicate behavior observed in experiments involving the species P. megacephala. The results have broader implications for the study of randomness in chemotactic models. Potential applications include the developments of novel algorithms for stochastic search in engineered complex systems such as robotic swarms.

  2. Microclimatic conditions of Lasius flavus ant mounds

    Science.gov (United States)

    Véle, Adam; Holuša, Jaroslav

    2016-11-01

    Like other organisms, ants require suitable microclimatic conditions for their development. Thus, ant species inhabiting colder climates build nest mounds that rise above the soil surface, presumably to obtain heating from solar radiation. Although some ant species construct mounds of organic materials, which generate substantial heat due to microbial metabolism, Lasius flavus mounds consists mostly of soil, not organic material. The use of artificial shading in the current study demonstrated that L. flavus depends on direct solar radiation to regulate the temperature in its mound-like nests. Temperatures were much lower in shaded mounds than in unshaded mounds and were likely low enough in shaded mounds to reduce ant development and reproduction. In areas where L. flavus and similar ants are undesirable, they might be managed by shading.

  3. Fungal Adaptations to Mutualistic Life with Ants

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus

    . However, in rare occasions fungal symbionts might come into contact with symbionts from other colonies. I showed that in both leaf-cutting ant genera incompatibility reactions between fungal strains can avoid intermixing of different strains, and that these reactions strengthen when genetic distance...... successful. To understand the evolutionary development of domestication of the fungus over the phylogeny of the Attine ants, I compared the average number of nuclei per cell for the fungal symbionts, for each of the different groups of fungus-growing ants. I found that the fungal symbionts of the paleo...... is increased. This pattern, however, becomes distorted when fungal symbionts are contested across ant genera. The most important mechanism in the succession of this mutualism of leaf-cutting ants is the controlled degradation of plant material. I show that in the area of Gamboa, Panama, the two leaf...

  4. Optimal Load Dispatch Using Ant Lion Optimization

    Directory of Open Access Journals (Sweden)

    Menakshi Mahendru Nischal

    2015-08-01

    Full Text Available This paper presents Ant lion optimization (ALO technique to solve optimal load dispatch problem. Ant lion optimization (ALO is a novel nature inspired algorithm. The ALO algorithm mimics the hunting mechanism of ant lions in nature. Five main steps of hunting prey such as the random walk of ants, building traps, entrapment of ants in traps, catching preys, and re-building traps are implemented. Optimal load dispatch (OLD is a method of determining the most efficient, low-cost and reliable operation of a power system by dispatching available electricity generation resources to supply load on the system. The primary objective of OLD is to minimize total cost of generation while honoring operational constraints of available generation resources. The proposed technique is implemented on 3, 6 & 20 unit test system for solving the OLD. Numerical results shows that the proposed method has good convergence property and better in quality of solution than other algorithms reported in recent literature.

  5. [The ants: a strategy of population concentration].

    Science.gov (United States)

    Zakharov, A A

    2011-01-01

    Ants are provided with a balanced system of reactions either to the original paucity of socia or to their secondary depopulation. This system can be defined as a strategy of population concentration. Both a successful reproduction of workers and queen fertilization are necessary conditions for ant communities' survival and development. Thus, the anthills must be large enough to ensure optimal conditions for reproduction. It is the strategy of population concentration that is directed to an accelerated attainment (or rehabilitation) by a socium of a state of stable development by way of concentrating the existent ant staff in an accessible number of viable nests. This strategy is realized throughout the life of ant communities by way of (a) fusing the starting family cells left by founder females, (b) fusing small anthills during artificial ant migrations, (c) uniting smaller socia or their joining other anthills, (d) reintegrating the secondary anthills (fragmentants) after an exogenous fragmentation of formicaries. Pooling and the attraction of deficient demographic resources from outside form the most efficient and quickest ways of reaching or restoring the threshold density levels. By realizing this strategy, the ants solve their paramount problems of anthill or settlement conservation at any particular time, as well as of providing some prospects for ant existence in the future. These problems are so vital for ant socia that they appear to hold priority over such other characteristics of utmost importance as genetic kinship or even species identity. The priority of social basics over genetic ones is unequivocally supported through mixed formicaries. A necessary condition for the realization of the strategy of population concentration is tolerance of highly developed social systems to the diversity of forms and to deviations from the norm. The use of one and the same mechanism at all stages of the life both of an individual socium and large ant settlements is

  6. La lutte des récits dans La Reine du Silence de Marie Nimier

    Directory of Open Access Journals (Sweden)

    Nashwa Fathi Abdel Maksoud Rashid

    2015-02-01

    Full Text Available Est-ce vraiment une chance d’avoir un père illustre ? Pour Marie Nimier, ce n’était qu’une souffrance. Elle était consciente de la difficulté d’être la fille d’un homme célèbre et de choisir de se lancer dans la carrière littéraire. Il y avait également une grande douleur à le perdre puis à remuer le passé afin de le découvrir  de nouveau. Vivant dans l’ombre paternelle d’un mythe littéraire, elle a toujours refusé d’exploiter la notoriété de son père Roger Nimier, chef de file des Hussards[i]. Ce grand écrivain est brutalement décédé en 1962 dans un accident de voiture en pleine jeunesse. Marie n’était qu’une petite fille de cinq ans. Toute sa vie elle s’efforcera de se faire un prénom : Très tôt en effet elle s’est sentie poussée vers le théâtre, la danse et la musique. Elle est entrée en littérature par hasard au milieu des années quatre-vingt. Une thèse sur les sirènes avait attiré l’attention de Françoise Verny, éditrice qui lui a conseillé d’en faire un roman. Sirène qui est publié chez Gallimard et couronné par l’Académie française sera suivi de sept autres romans[ii], traduits dans plusieurs pays du  monde[iii]. En 2004, Marie Nimier publie La Reine du Silence qui sera récompensé par le prix Médicis. Cet ouvrage n’est que l’histoire de la douleur d’une fille qui a perdu son père et c’est Roger Nimier vu par les yeux de sa fille qui apparaît au fil des pages. [i] Roger Nimier qui a marqué le paysage littéraire des années 50 en se positionnant contre le mouvement dominant de l’époque : l’existentialisme. Il est chef de file des Hussards, jeunes écrivains classés à droite et opposés au roman sartrien (Antoine Blondin, Jacques Laurent, Michel Déon…. [ii] Sirène en 1985,La Girafe en 1987, Anatomie d’un chœur en 1990, L’Hypnotisme à la portée de tous en 1992, La Caresse en 1994, Celui qui court derrière l’oiseau en 1996, Domino

  7. Arhitektuurselt põnev, kuid muuseumina saamatu võidutöö : ERM / Rein Murula ; interv. Reet Varblane

    Index Scriptorium Estoniae

    Murula, Rein, 1955-

    2006-01-01

    Intervjuu Eesti Rahva Muuseumi hoone arhitektuurivõistluse žüriiliikme arhitekt Rein Murulaga. Konkursist, kaasaegsest muuseumihoonest, võidutööst "Memory Field" (autorid itaalia arhitekt Dan Dorell, liibanoni arhitekt Lina Ghotmeh, jaapani arhitekt Tsuyoshi Tane), II preemia saanud tööst "Gems" (autorid soome arhitektid Juho Grönholm, Antti Nousjoki, Janne Teräsvirta, Samuli Woolston), III preemia saanud tööst "Estonia is on the verge of a new millennium" (autorid austria arhitektid Alfred Bramberger, Thomas Pucher, Heidrun Steinhauser, Martin Mathy, Christa Pucher), ostupreemia pälvinud töödest "Crochet" (AB Kosmos: Ott Kadarik, Villem Tomiste, Mihkel Tüür, Krista Saluveer, Urmas Oja) ja "Lake Whisper" (autorid šveitsi arhitektid Manuel Bieler, Marco de Francesco, Antoine Robert-Grandpierre, Laurent Saurer)

  8. Arhitektuurselt põnev, kuid muuseumina saamatu võidutöö : ERM / Rein Murula ; interv. Reet Varblane

    Index Scriptorium Estoniae

    Murula, Rein, 1955-

    2006-01-01

    Intervjuu Eesti Rahva Muuseumi hoone arhitektuurivõistluse žüriiliikme arhitekt Rein Murulaga. Konkursist, kaasaegsest muuseumihoonest, võidutööst "Memory Field" (autorid itaalia arhitekt Dan Dorell, liibanoni arhitekt Lina Ghotmeh, jaapani arhitekt Tsuyoshi Tane), II preemia saanud tööst "Gems" (autorid soome arhitektid Juho Grönholm, Antti Nousjoki, Janne Teräsvirta, Samuli Woolston), III preemia saanud tööst "Estonia is on the verge of a new millennium" (autorid austria arhitektid Alfred Bramberger, Thomas Pucher, Heidrun Steinhauser, Martin Mathy, Christa Pucher), ostupreemia pälvinud töödest "Crochet" (AB Kosmos: Ott Kadarik, Villem Tomiste, Mihkel Tüür, Krista Saluveer, Urmas Oja) ja "Lake Whisper" (autorid šveitsi arhitektid Manuel Bieler, Marco de Francesco, Antoine Robert-Grandpierre, Laurent Saurer)

  9. Kas ja kui palju jälgite kutsetunnistuse olemasolu uue töötaja palkamisel? Kas ja kui palju teie firmas kutsetunnistusega töötajaid on? / Eve Reitalu, Ain Käpp, Rein Must ... [jt.

    Index Scriptorium Estoniae

    2012-01-01

    Küsimustele vastasid Arctic Sport fitnessvaldkonna juht Eve Reitalu, TallinnHotels OÜ / Aldera Hotell OÜ tegevdirektor Ain Käpp, AS Decora Ehitus direktor Rein Must, OÜ Afterone juhataja Argo Tõruke ja DPD Eesti ASi tegevjuht Tarmo Tael

  10. Individual Recognition in Ant Queens

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Heinze, Jürgen

    2005-01-01

    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......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...... 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...

  11. Some enzymic activities of two Australian ant venoms: a jumper ant Myrmecia pilosula and a bulldog ant Myrmecia pyriformis.

    Science.gov (United States)

    Matuszek, M A; Hodgson, W C; King, R G; Sutherland, S K

    1994-12-01

    Venoms from two related Australian ants, a jumper ant (Myrmecia pilosula) and a bulldog ant (Myrmecia pyriformis), were quantitatively analysed for the following enzymic activities: phospholipase A2, phospholipase B, phospholipase C, hyaluronidase, esterase, acid phosphatase, alkaline phosphatase and phosphodiesterase. Both venoms contained phospholipase A2, phospholipase B, hyaluronidase, acid phosphatase and alkaline phosphatase activities. Myrmecia pyriformis venom had significantly greater phospholipase B, acid phosphatase and alkaline phosphatase activities than Myrmecia pilosula venom. No detectable quantities of phospholipase C, esterase or phosphodiesterase activities were found in either venom.

  12. Ant-lepidopteran associations along African forest edges

    Science.gov (United States)

    Dejean, Alain; Azémar, Frédéric; Libert, Michel; Compin, Arthur; Hérault, Bruno; Orivel, Jérôme; Bouyer, Thierry; Corbara, Bruno

    2017-02-01

    Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

  13. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    Science.gov (United States)

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  14. Differential Recruitment of Camponotus femoratus (Fabricius) Ants in Response to Ant Garden Herbivory.

    Science.gov (United States)

    Vicente, R E; Dáttilo, W; Izzo, T J

    2014-12-01

    Although several studies have shown that ants can recognize chemical cues from their host plants in ant-plant systems, it is poorly demonstrated in ant gardens (AGs). In this interaction, ant species constantly interact with various epiphyte species. Therefore, it is possible to expect a convergence of chemical signals released by plants that could be acting to ensure that ants are able to recognize and defend epiphyte species frequently associated with AGs. In this study, it was hypothesized that ants recognize and differentiate among chemical stimuli released by AG epiphytes and non-AG epiphytes. We experimentally simulated leaf herbivore damage on three epiphyte species restricted to AGs and a locally abundant understory herb, Piper hispidum, in order to quantify the number of recruited Camponotus femoratus (Fabricius) defenders. When exposed to the AG epiphytes Peperomia macrostachya and Codonanthe uleana leaves, it was observed that the recruitment of C. femoratus workers was, on average, respectively 556% and 246% higher than control. However, the number of ants recruited by the AG epiphyte Markea longiflora or by the non-AG plant did not differ from paper pieces. This indicated that ants could discern between chemicals released by different plants, suggesting that ants can select better plants. These results can be explained by evolutionary process acting on both ants' capability in discerning plants' chemical compounds (innate attraction) or by ants' learning based on the epiphyte frequency in AGs (individual experience). To disentangle an innate behavior, a product of classical coevolutionary process, from an ant's learned behavior, is a complicated but important subject to understand in the evolution of ant-plant mutualisms.

  15. How to be an ant on figs

    Science.gov (United States)

    Bain, Anthony; Harrison, Rhett D.; Schatz, Bertrand

    2014-05-01

    Mutualistic interactions are open to exploitation by one or other of the partners and a diversity of other organisms, and hence are best understood as being embedded in a complex network of biotic interactions. Figs participate in an obligate mutualism in that figs are dependent on agaonid fig wasps for pollination and the wasps are dependent on fig ovules for brood sites. Ants are common insect predators and abundant in tropical forests. Ants have been recorded on approximately 11% of fig species, including all six subgenera, and often affect the fig-fig pollinator interaction through their predation of either pollinating and parasitic wasps. On monoecious figs, ants are often associated with hemipterans, whereas in dioecious figs ants predominantly prey on fig wasps. A few fig species are true myrmecophytes, with domatia or food rewards for ants, and in at least one species this is linked to predation of parasitic fig wasps. Ants also play a role in dispersal of fig seeds and may be particularly important for hemi-epiphytic species, which require high quality establishment microsites in the canopy. The intersection between the fig-fig pollinator and ant-plant systems promises to provide fertile ground for understanding mutualistic interactions within the context of complex interaction networks.

  16. Collective search by ants in microgravity

    Directory of Open Access Journals (Sweden)

    Stefanie M. Countryman

    2015-03-01

    Full Text Available The problem of collective search is a tradeoff between searching thoroughly and covering as much area as possible. This tradeoff depends on the density of searchers. Solutions to the problem of collective search are currently of much interest in robotics and in the study of distributed algorithms, for example to design ways that without central control robots can use local information to perform search and rescue operations. Ant colonies operate without central control. Because they can perceive only local, mostly chemical and tactile cues, they must search collectively to find resources and to monitor the colony's environment. Examining how ants in diverse environments solve the problem of collective search can elucidate how evolution has led to diverse forms of collective behavior. An experiment on the International Space Station in January 2014 examined how ants (Tetramorium caespitum perform collective search in microgravity. In the ISS experiment, the ants explored a small arena in which a barrier was lowered to increase the area and thus lower ant density. In microgravity, relative to ground controls, ants explored the area less thoroughly and took more convoluted paths. It appears that the difficulty of holding on to the surface interfered with the ants’ ability to search collectively. Ants frequently lost contact with the surface, but showed a remarkable ability to regain contact with the surface.

  17. Pheromone disruption of Argentine ant trail integrity

    Science.gov (United States)

    Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

    2008-01-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

  18. Ant colonies for the travelling salesman problem.

    Science.gov (United States)

    Dorigo, M; Gambardella, L M

    1997-01-01

    We describe an artificial ant colony capable of solving the travelling salesman problem (TSP). Ants of the artificial colony are able to generate successively shorter feasible tours by using information accumulated in the form of a pheromone trail deposited on the edges of the TSP graph. Computer simulations demonstrate that the artificial ant colony is capable of generating good solutions to both symmetric and asymmetric instances of the TSP. The method is an example, like simulated annealing, neural networks and evolutionary computation, of the successful use of a natural metaphor to design an optimization algorithm.

  19. Faster-is-slower effect in escaping ants revisited: Ants do not behave like humans

    CERN Document Server

    Parisi, Daniel R; Josens, Roxana

    2014-01-01

    In this work we studied the trajectories, velocities and densities of ants when egressing under controlled levels of stress produced by a chemical repellent at different concentrations. We found that, unlike other animals escaping under life-and-death conditions and pedestrian simulations, ants do not produce a higher density zone near the exit door. Instead, ants are uniformly distributed over the available space allowing for efficient evacuations. Consequently, the faster-is-slower effect observed in ants (Soria et al., 2012) is clearly of a different nature to that predicted by de social force model. In the case of ants, the minimum evacuation time is correlated with the lower probability of taking backward steps. Thus, as biological model ants have important differences that make their use inadvisable for the design of human facilities.

  20. Stealthy invaders: the biology of Cardiocondyla tramp ants

    DEFF Research Database (Denmark)

    Heinze, J.; Cremer, Sylvia; Eckl, N.

    2006-01-01

    Many invasive ant species, such as the Argentine ant or the red imported fire ant, have huge colonies with thousands of mass-foraging workers, which quickly monopolise resources and therefore represent a considerable threat to the native ant fauna. Cardiocondyla obscurior and several other species...

  1. 9 CFR 354.121 - Ante-mortem inspection.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Ante-mortem inspection. 354.121 Section 354.121 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Procedures; Ante-Mortem Inspections § 354.121 Ante-mortem inspection. An ante-mortem inspection of...

  2. Faster-is-slower effect in escaping ants revisited: Ants do not behave like humans

    OpenAIRE

    Parisi, Daniel R.; Soria, Sabrina A; Josens, Roxana

    2014-01-01

    In this work we studied the trajectories, velocities and densities of ants when egressing under controlled levels of stress produced by a chemical repellent at different concentrations. We found that, unlike other animals escaping under life-and-death conditions and pedestrian simulations, ants do not produce a higher density zone near the exit door. Instead, ants are uniformly distributed over the available space allowing for efficient evacuations. Consequently, the faster-is-slower effect o...

  3. Multitasking in a plant-ant interaction: how does Acacia myrtifolia manage both ants and pollinators?

    Science.gov (United States)

    Martínez-Bauer, Angélica E; Martínez, Gerardo Cerón; Murphy, Daniel J; Burd, Martin

    2015-06-01

    Plant associations with protective ants are widespread among angiosperms, but carry the risk that ants will deter pollinators as well as herbivores. Such conflict, and adaptations to ameliorate or prevent the conflict, have been documented in African and neotropical acacias. Ant-acacia associations occur in Australia, but little is known of their ecology. Moreover, recent phylogenetic evidence indicates that Australian acacias are only distantly related to African and American acacias, providing an intercontinental natural experiment in the management of ant-pollinator conflict. We examined four populations of Acacia myrtifolia over a 400-km environmental gradient in southeastern Australia using ant and pollinator exclusion as well as direct observation of ants and pollinators to assess the potential for ant-pollinator conflict to affect seed set. Native bees were the only group of floral visitors whose visitation rates were a significant predictor of fruiting success, although beetles and wasps may play an important role as "insurance" pollinators. We found no increase in pollinator visitation or fruiting success following ant exclusion, even with large sample sizes and effective exclusion. Because ants are facultative visitors to A. myrtifolia plants, their presence may be insufficient to interfere greatly with floral visitors. It is also likely that the morphological location of extrafloral nectaries tends to draw ants away from reproductive parts, although we commonly observed ants on inflorescences, so the spatial separation is not strict. A. myrtifolia appears to maintain a generalized mutualism over a wide geographic range without the need for elaborate adaptations to resolve ant-pollinator conflict.

  4. Deterministic ants in labirynth -- information gained by map sharing

    CERN Document Server

    Malinowski, Janusz

    2014-01-01

    A few of ant robots are dropped to a labirynth, formed by a square lattice with a small number of nodes removed. Ants move according to a deterministic algorithm designed to explore all corridors. Each ant remembers the shape of corridors which she has visited. Once two ants met, they share the information acquired. We evaluate how the time of getting a complete information by an ant depends on the number of ants, and how the length known by an ant depends on time. Numerical results are presented in the form of scaling relations.

  5. Fire disturbance disrupts an acacia ant-plant mutualism in favor of a subordinate ant species.

    Science.gov (United States)

    Sensenig, Ryan L; Kimuyu, Duncan K; Ruiz Guajardo, Juan C; Veblen, Kari E; Riginos, Corinna; Young, Truman P

    2017-05-01

    Although disturbance theory has been recognized as a useful framework in examining the stability of ant-plant mutualisms, very few studies have examined the effects of fire disturbance on these mutualisms. In myrmecophyte-dominated savannas, fire and herbivory are key drivers that could influence ant-plant mutualisms by causing complete colony mortality and/or decreasing colony size, which potentially could alter dominance hierarchies if subordinate species are more fire resilient. We used a large-scale, replicated fire experiment to examine long-term effects of fire on acacia-ant community composition. To determine if fire shifted ant occupancy from a competitive dominant to a subordinate ant species, we surveyed the acacia-ant community in 6-7 yr old burn sites and examined how the spatial scale of these burns influenced ant community responses. We then used two short-term fire experiments to explore possible mechanisms for the shifts in community patterns observed. Because survival of ant colonies is largely dependent on their ability to detect and escape an approaching fire, we first tested the evacuation response of all four ant species when exposed to smoke (fire signal). Then to better understand how fire and its interaction with large mammal herbivory affect the density of ants per tree, we quantified ant worker density in small prescribed burns within herbivore exclusion plots. We found clear evidence suggesting that fire disturbance favored the subordinate ant Crematogaster nigriceps more than the dominant and strong mutualist ant C. mimosae, whereby C. nigriceps (1) was the only species to occupy a greater proportion of trees in 6-7 yr old burn sites compared to unburned sites, (2) had higher burn/unburn tree ratios with increasing burn size, and (3) evacuated significantly faster than C. mimosae in the presence of smoke. Fire and herbivory had opposite effects on ant density per meter of branch for both C. nigriceps and C. mimosae, with fire

  6. Mutualism exploitation: predatory drosophilid larvae sugar-trap ants and jeopardize facultative ant-plant mutualism.

    Science.gov (United States)

    Vidal, Mayra C; Sendoya, Sebastian F; Oliveira, Paulo S

    2016-07-01

    An open question in the evolutionary ecology of ant-plant facultative mutualism is how other members of the associated community can affect the interaction to a point where reciprocal benefits are disrupted. While visiting Qualea grandiflora shrubs to collect sugary rewards at extrafloral nectaries, tropical savanna ants deter herbivores and reduce leaf damage. Here we show that larvae of the fly Rhinoleucophenga myrmecophaga, which develop on extrafloral nectaries, lure potentially mutualistic, nectar-feeding ants and prey on them. Foraging ants spend less time on fly-infested foliage. Field experiments showed that predation (or the threat of predation) on ants by fly larvae produces cascading effects through three trophic levels, resulting in fewer protective ants on leaves, increased numbers of chewing herbivores, and greater leaf damage. These results reveal an undocumented mode of mutualism exploitation by an opportunistic predator at a plant-provided food source, jeopardizing ant-derived protection services to the plant. Our study documents a rather unusual case of predation of adult ants by a dipteran species and demonstrates a top-down trophic cascade within a generalized ant-plant mutualism. © 2016 by the Ecological Society of America.

  7. KohonAnts: A Self-Organizing Ant Algorithm for Clustering and Pattern Classification

    CERN Document Server

    Fernandes, C; Merelo, J J; Ramos, V; Laredo, J L J

    2008-01-01

    In this paper we introduce a new ant-based method that takes advantage of the cooperative self-organization of Ant Colony Systems to create a naturally inspired clustering and pattern recognition method. The approach considers each data item as an ant, which moves inside a grid changing the cells it goes through, in a fashion similar to Kohonen's Self-Organizing Maps. The resulting algorithm is conceptually more simple, takes less free parameters than other ant-based clustering algorithms, and, after some parameter tuning, yields very good results on some benchmark problems.

  8. Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    the more basal attine genera use substrates such as flowers, plant debris, small twigs, insect feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide...... or different efficiencies of enzyme function. Fungal enzymes that degrade plant cell walls may have functionally co-evolved with the ants in this scenario. We explore this hypothesis with direct measurements of enzyme activity in fungus gardens in 12 species across 8 genera spanning the entire phylogeny...... and diversity of life-styles within the attine clade. We find significant differences in enzyme activity between different genera and life-styles of the ants. How these findings relate to attine ant coevolution and crop optimization are discussed....

  9. Discrimination Behavior in the Supercolonial Pharaoh Ant

    DEFF Research Database (Denmark)

    Pontieri, Luigi

    an increasing need to understand which factors promote the ecological dominance of these species, and particularly how the discrimination of both conspecifics and heterospecifics (including parasites) might influence structure and ecological success of invasive populations. In this PhD thesis I investigated...... the discrimination behavior of the invasive pharaoh ant (Monomorium pharaonis) as a model for other invasive and supercolonial ant species. The pharaoh ant is one of the few ant species that can be reared in the laboratory for many generations. Furthermore, the possibility to do controlled crosses of colonies...... provides the unique opportunity to establish colonies of different genetic composition. These traits make this species a suitable study subject to set up behavioral experiments that aim to investigate which factors, and to which extent, might influence the inter- and intraspecific discrimination abilities...

  10. Rose Atoll - Eradication of Invasive Ants

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — There are at least 9 species of ants introduced to Rose Atoll, including species that tend to scale insects that are devastating the Pisonia grandis trees on the 15...

  11. Discrimination Behavior in the Supercolonial Pharaoh Ant

    DEFF Research Database (Denmark)

    Pontieri, Luigi

    an increasing need to understand which factors promote the ecological dominance of these species, and particularly how the discrimination of both conspecifics and heterospecifics (including parasites) might influence structure and ecological success of invasive populations. In this PhD thesis I investigated...... the discrimination behavior of the invasive pharaoh ant (Monomorium pharaonis) as a model for other invasive and supercolonial ant species. The pharaoh ant is one of the few ant species that can be reared in the laboratory for many generations. Furthermore, the possibility to do controlled crosses of colonies...... provides the unique opportunity to establish colonies of different genetic composition. These traits make this species a suitable study subject to set up behavioral experiments that aim to investigate which factors, and to which extent, might influence the inter- and intraspecific discrimination abilities...

  12. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem

    DEFF Research Database (Denmark)

    Stuble, Katharine L.; Kirkman, L. Katherine; Carroll, C. Ronald

    2011-01-01

    , the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants...

  13. Using pleometrosis (multiple queens) and pupae transplantation to boost weaver ant (Oecophylla smaragdina) colony growth in ant nurseries

    DEFF Research Database (Denmark)

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

    2011-01-01

    Weaver ants (Oecophylla spp.) are increasingly being used for biocontrol and are targeted for future production of insect protein in ant farms. An efficient production of live ant colonies may facilitate the utilization of these ants but the production of mature colonies is hampered by the long t...

  14. An Improved Heuristic Ant-Clustering Algorithm

    Institute of Scientific and Technical Information of China (English)

    Yunfei Chen; Yushu Liu; Jihai Zhao

    2004-01-01

    An improved heuristic ant-clustering algorithm(HAC)is presented in this paper. A device of 'memory bank' is proposed,which can bring forth heuristic knowledge guiding ant to move in the bi-dimension grid space.The device experiments on real data sets and synthetic data sets.The results demonstrate that HAC has superiority in misclassification error rate and runtime over the classical algorithm.

  15. Ants (Formicidae): models for social complexity.

    Science.gov (United States)

    Smith, Chris R; Dolezal, Adam; Eliyahu, Dorit; Holbrook, C Tate; Gadau, Jürgen

    2009-07-01

    The family Formicidae (ants) is composed of more than 12,000 described species that vary greatly in size, morphology, behavior, life history, ecology, and social organization. Ants occur in most terrestrial habitats and are the dominant animals in many of them. They have been used as models to address fundamental questions in ecology, evolution, behavior, and development. The literature on ants is extensive, and the natural history of many species is known in detail. Phylogenetic relationships for the family, as well as within many subfamilies, are known, enabling comparative studies. Their ease of sampling and ecological variation makes them attractive for studying populations and questions relating to communities. Their sociality and variation in social organization have contributed greatly to an understanding of complex systems, division of labor, and chemical communication. Ants occur in colonies composed of tens to millions of individuals that vary greatly in morphology, physiology, and behavior; this variation has been used to address proximate and ultimate mechanisms generating phenotypic plasticity. Relatedness asymmetries within colonies have been fundamental to the formulation and empirical testing of kin and group selection theories. Genomic resources have been developed for some species, and a whole-genome sequence for several species is likely to follow in the near future; comparative genomics in ants should provide new insights into the evolution of complexity and sociogenomics. Future studies using ants should help establish a more comprehensive understanding of social life, from molecules to colonies.

  16. Visual scene perception in navigating wood ants.

    Science.gov (United States)

    Lent, David D; Graham, Paul; Collett, Thomas S

    2013-04-22

    Ants, like honeybees, can set their travel direction along foraging routes using just the surrounding visual panorama. This ability gives us a way to explore how visual scenes are perceived. By training wood ants to follow a path in an artificial scene and then examining their path within transformed scenes, we identify several perceptual operations that contribute to the ants' choice of direction. The first is a novel extension to the known ability of insects to compute the "center of mass" of large shapes: ants learn a desired heading toward a point on a distant shape as the proportion of the shape that lies to the left and right of the aiming point--the 'fractional position of mass' (FPM). The second operation, the extraction of local visual features like oriented edges, is familiar from studies of shape perception. Ants may use such features for guidance by keeping them in desired retinal locations. Third, ants exhibit segmentation. They compute the learned FPM over the whole of a simple scene, but over a segmented region of a complex scene. We suggest how the three operations may combine to provide efficient directional guidance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Toxic industrial deposit remediation by ant activity

    Science.gov (United States)

    Jilkova, Veronika; Frouz, Jan

    2016-04-01

    Toxic industrial deposits are often contaminated by heavy metals and the substrates have low pH values. In such systems, soil development is thus slowed down by high toxicity and acidic conditions which are unfavourable to soil fauna. Ants (Hymenoptera, Formicidae) are considered tolerant to heavy metal pollution and are known to increase organic matter content and microbial activity in their nests. Here, we focused on soil remediation caused by three ant species (Formica sanguinea, Lasius niger, and Tetramorium sp.) in an ore-washery sedimentation basin near Chvaletice (Czech Republic). Soil samples were taken from the centre of ant nests and from the nest surroundings (>3 m from nests). Samples were then analyzed for microbial activity and biomass and contents of organic matter and nutrients. As a result, ant species that most influenced soil properties was F. sanguinea as there were higher microbial activity and total nitrogen and ammonia contents in ant nests than in the surrounding soil. We expected such a result because F. sanguinea builds conspicuous large nests and is a carnivorous species that brings substantial amounts of nitrogen in insect prey to their nests. Effects of the other two ant species might be lower because of smaller nests and different feeding habits as they rely mainly on honeydew from aphids or on plant seeds that do not contain much nutrients.

  18. Congestion and communication in confined ant traffic

    Science.gov (United States)

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

    2014-03-01

    Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

  19. Fire ants perpetually rebuild sinking towers

    Science.gov (United States)

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig

    2017-07-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  20. Entangled active matter: From cells to ants

    Science.gov (United States)

    Hu, D. L.; Phonekeo, S.; Altshuler, E.; Brochard-Wyart, F.

    2016-07-01

    Both cells and ants belong to the broad field of active matter, a novel class of non-equilibrium materials composed of many interacting units that individually consume energy and collectively generate motion or mechanical stresses. However cells and ants differ from fish and birds in that they can support static loads. This is because cells and ants can be entangled, so that individual units are bound by transient links. Entanglement gives cells and ants a set of remarkable properties usually not found together, such as the ability to flow like a fluid, spring back like an elastic solid, and self-heal. In this review, we present the biology, mechanics and dynamics of both entangled cells and ants. We apply concepts from soft matter physics and wetting to characterize these systems as well as to point out their differences, which arise from their differences in size. We hope that our viewpoints will spur further investigations into cells and ants as active materials, and inspire the fabrication of synthetic active matter.

  1. Bacterial associates of arboreal ants and their putative functions in an obligate ant-plant mutualism.

    Science.gov (United States)

    Eilmus, Sascha; Heil, Martin

    2009-07-01

    Bacterial communities are highly diverse and have great ecological importance. In the present study, we used an in silico analysis of terminal restriction fragments (tRF) to characterize the bacterial community of the plant ant Pseudomyrmex ferrugineus. This species is an obligate inhabitant of Acacia myrmecophytes and feeds exclusively on plant-derived food sources. Ants are the dominant insect group in tropical rain forests. Associations of ants with microbes, which contribute particularly to the ants' nitrogen nutrition, could allow these insects to live on mostly or entirely plant-based diets and could thus contribute to the explanation of the high abundances that are reached by tropical ants. We found tRF patterns representing at least 30 prokaryotic taxa, of which the Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Planctomycetes, Proteobacteria, and Spirochaetes comprised 93%. Because most bacterial taxa were found in all ant-derived samples studied and because the bacteria detected on the ants' host plant revealed little overlap with this community, we regard our results as reliably representing the bacterial community that is associated with P. ferrugineus. Genera with a likely function as ant symbionts were Burkholderia, Pantoea, Weissella, and several members of the Enterobacteriaceae. The presence of these and various other groups was confirmed via independent PCR and cultivation approaches. Many of the bacteria that we detected belong to purportedly N-fixing taxa. Bacteria may represent important further partners in ant-plant mutualisms, and their influences on ant nutrition can contribute to the extraordinary abundance and evolutionary success of tropical arboreal ants.

  2. Solution to the problem of ant being stuck by ant colony routing algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jing; TONG Wei-ming

    2009-01-01

    Many ant colony routing (ACR) algorithms have been presented in recent years, but few have studied the problem that ants will get stuck with probability in any terminal host when they are searching paths to route packets around a network. The problem has to be faced when designing and implementing the ACR algorithm. This article analyzes in detail the differences between the ACR and the ant colony optimization (ACO). Besides, particular restrictions on the ACR are pointed out and the three causes of ant being-stuck problem are obtained. Furthermore, this article proposes a new ant searching mechanism through dual path-checking and online routing loop removing by every intermediate node an ant visited and the destination host respectively, to solve the problem of ant being stuck and routing loop simultaneously. The result of numerical simulation is abstracted from one real network. Compared with existing two typical ACR algorithms, it shows that the proposed algorithm can settle the problem of ant being stuck and achieve more effective searching outcome for optimization path.

  3. Applied Ecology and Control of Imported Fire Ants and Argentine Ants

    Science.gov (United States)

    The red imported fire ant, Solenopsis invicta Buren, and Argentine ant, Linepithema humile (Mayr), are invasive species that are major pests in urban, natural, and agricultural habitats. The goal of this dissertation was to study aspects the chemical sensitivity, behavior, and ecology of each specie...

  4. Taxonomic and functional ecology of montane ants

    Directory of Open Access Journals (Sweden)

    Tom Rhys Bishop

    2017-04-01

    Full Text Available Why is biological diversity distributed in the way that it is? This question has been central to ecology and biogeography for centuries and is of great importance for pure and applied reasons. I use a functional trait view of ecology to complement standard sampling protocols to better understand the distribution and structure of ant (Hymenoptera: Formicidae diversity across mountains. I use a long-term dataset of ant diversity and abundance, combined with a recently collected morphological trait dataset to examine how the alpha and beta diversity of ants responds to changes in temperature along an extensive elevational gradient in southern Africa. In addition, I link morphological thermoregulatory traits to each other and to the environment with a new database of ant elevational abundances from across the globe. Finally, I analyse how physiological thermal tolerances vary and constrain foraging patterns in montane ants. I find that temperature is a strong driver of both alpha and beta diversity patterns. In addition, morphological traits such as colour and body size are found to have a significant relationship to ambient temperatures. This relationship also implies that the relative abundances of different ant species change depending on their thermoregulatory traits (colour and body size and the surrounding thermal environment. Furthermore, the critical thermal minimum (CTmin of the ant species investigated and the lowest environmental temperatures are found to be key in constraining foraging activity patterns. The data presented here strengthen and link existing ideas about how thermoregulation can influence ecological communities and also suggests important ways in which diversity patterns may change in the future.

  5. Ecology of a fig ant-plant

    Science.gov (United States)

    Harrison, Rhett D.

    2014-05-01

    Mutualistic interactions are embedded in networks of interactions that affect the benefits accruing to the mutualistic partners. Figs and their pollinating wasps are engaged in an obligate mutualism in which the fig is dependent on the fig pollinator for pollination services and the pollinator is dependent on fig ovules for brood sites. This mutualism is exploited by non-pollinating fig wasps that utilise the same ovules, but do not provide a pollination service. Most non-pollinating wasps oviposit from outside the inflorescence (syconium), where they are vulnerable to ant predation. Ficus schwarzii is exposed to high densities of non-pollinating wasps, but Philidris sp. ants patrolling the syconia prevent them from ovipositing. Philidris rarely catch wasps, but the fig encourages the patrolling by providing a reward through extra-floral nectaries on the surface of syconia. Moreover, the reward is apparently only produced during the phase when parasitoids are ovipositing. An ant-exclusion experiment demonstrated that, in the absence of ants, syconia were heavily attacked and many aborted as a consequence. Philidris was normally rare on the figs during the receptive phase or at the time of day when wasp offspring are emerging, so predation on pollinators was limited. However, Myrmicaria sp. ants, which only occurred on three trees, preyed substantially on pollinating as well as non-pollinating wasps. F. schwarzii occurs in small clusters of trees and has an exceptionally rapid crop turnover. These factors appear to promote high densities of non-pollinating wasps and, as a consequence, may have led to both a high incidence of ants on trees and increased selective pressure on fig traits that increase the payoffs of the fig-ant interaction for the fig. The fig receives no direct benefit from the reward it provides, but protects pollinating wasps that will disperse its pollen.

  6. Oecophylla smaragdina food conversion efficiency: prospects for ant farming

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim

    2011-01-01

    Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming...... can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost-benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina...... (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood...

  7. The use of weaver ants (Oecophylla spp.) in tropical agriculture

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim

    2011-01-01

    Canopy dwelling weaver ants are widely distributed throughout the Old World Tropics where they build up high densities on their host trees. If managed properly the high number of ants will control a range of pest insects and benefit crop production. Simultaneously the ant larvae production, fuelled...... by the consumed pest insects, can be harvested and utilised for nutrition as they are tasty and high in proteins, vitamins and minerals. Thus, plantations may function as ant farms and in addition to plant production also hosts the production of edible animal protein. In this setup harmful pest insects are turned...... farming as a way forward to solve an increasing future demand for protein. Weaver ant farming may build on natural food collected by the ants or alternatively be boosted by feeding the ant colonies actively with protein and sugar. In both cases, when ant biocontrol is combined with ant farming...

  8. Oecophylla smaragdina food conversion efficiency: prospects for ant farming

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim

    2011-01-01

    (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood......Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming...... can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost-benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina...

  9. The descent of ant: field-measured performance of gliding ants.

    Science.gov (United States)

    Munk, Yonatan; Yanoviak, Stephen P; Koehl, M A R; Dudley, Robert

    2015-05-01

    Gliding ants avoid predatory attacks and potentially mortal consequences of dislodgement from rainforest canopy substrates by directing their aerial descent towards nearby tree trunks. The ecologically relevant measure of performance for gliding ants is the ratio of net horizontal to vertical distance traveled over the course of a gliding trajectory, or glide index. To study variation in glide index, we measured three-dimensional trajectories of Cephalotes atratus ants gliding in natural rainforest habitats. We determined that righting phase duration, glide angle, and path directness all significantly influence variation in glide index. Unsuccessful landing attempts result in the ant bouncing off its target and being forced to make a second landing attempt. Our results indicate that ants are not passive gliders and that they exert active control over the aerodynamic forces they experience during their descent, despite their apparent lack of specialized control surfaces. © 2015. Published by The Company of Biologists Ltd.

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

    Science.gov (United States)

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Liqiang Liu

    2014-01-01

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

  12. Ants as shell collectors: notes on land snail shells found around ant nests

    Directory of Open Access Journals (Sweden)

    Barna Páll-Gergely

    2009-03-01

    Full Text Available We investigated the shell collecting activities of harvester ants (Messor spp. in semi-arid grasslands and shrubs in Turkey. We found eleven species of snails in the area, two of them were not collected by ants. Eight – mainly small sized – snail species were found on ant nests in a habitat characterized by shrubs, three in rocky grassland and four in a grassland habitat. Some shells (e.g. Chondrus zebrula tantalus, Multidentula ovularis might be taken into the nests, and we hypothesise that some of these snail species are consumed by ants (Monacha spp.. From a fauna inventory perspective, shell collecting activities of harvester ant may help malacologists to find snail species which are normally hidden for a specialist (e.g. Oxychilus hydatinus, Cecilioides spp. due to their special habits.

  13. The distribution of weaver ant pheromones on host trees

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2007-01-01

    The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for ...... to leaves. Also there was a positive correlation between spot density and the likelihood of being detected by ants. Anal spots may thus function as reliable cues to interacting species and be an important factor in shaping the community around Oecophylla colonies.......The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested...... for correlations between spot density, ant activity and the likelihood of being detected by an ant. Spots were only found on trees with ants. On ant-trees, spots were distributed throughout the trees but with higher densities in areas with high ant activity and pheromone densities were higher on twigs compared...

  14. Impacts of residual insecticide barriers on perimeter-invading ants, with particular reference to the odorous house ant, Tapinoma sessile.

    Science.gov (United States)

    Scharf, Michael E; Ratliff, Catina R; Bennett, Gary W

    2004-04-01

    Three liquid insecticide formulations were evaluated as barrier treatments against perimeter-invading ants at a multifamily housing complex in West Lafayette, IN. Several ant species were present at the study site, including (in order of abundance) pavement ant, Tetramorium caespitum (L.); honey ant, Prenolepis imparis (Say); odorous house ant, Tapinoma sessile (Say); thief ant, Solenopsis molesta (Say); acrobat ant, Crematogaster ashmeadi (Mayr); crazy ant, Paratrechina longicornis (Latrielle), field ants, Formica spp.; and carpenter ant Camponotus pennsylvanicus (DeGeer). Studies began in May 2001 and concluded 8 wk later in July. Individual replicate treatments were placed 0.61 in (2 feet) up and 0.92 m (3 feet) out from the ends of 46.1 by 10.1-m (151 by 33-foot) apartment buildings. Ant sampling was performed with 10 placements of moist cat food for 1 h within treatment zones, followed by capture and removal of recruited ants for later counting. All treatments led to substantial reductions in ant numbers relative to untreated controls. The most effective treatment was fipronil, where 2% of before-treatment ant numbers were present at 8 wk after treatment. Both imidacloprid and cyfluthrin barrier treatments had efficacy comparative with fipronil, but to 4 and 2 wk, respectively. Odorous house ants were not sampled before treatment. Comparisons of ant species composition between treatments and controls revealed an increase in odorous house ant frequencies at 1-8 wk after treatment in treated locations only. These results demonstrate efficacy for both nonrepellent and repellent liquid insecticides as perimeter treatments for pest ants. In addition, our findings with odorous house ant highlight an apparent invasive-like characteristic of this species that may contribute to its dramatic increase in structural infestation rates in many areas of the United States.

  15. Fossil evidence for the early ant evolution

    Science.gov (United States)

    Perrichot, Vincent; Lacau, Sébastien; Néraudeau, Didier; Nel, André

    2008-02-01

    Ants are one of the most studied insects in the world; and the literature devoted to their origin and evolution, systematics, ecology, or interactions with plants, fungi and other organisms is prolific. However, no consensus yet exists on the age estimate of the first Formicidae or on the origin of their eusociality. We review the fossil and biogeographical record of all known Cretaceous ants. We discuss the possible origin of the Formicidae with emphasis on the most primitive subfamily Sphecomyrminae according to its distribution and the Early Cretaceous palaeogeography. And we review the evidence of true castes and eusociality of the early ants regarding their morphological features and their manner of preservation in amber. The mid-Cretaceous amber forest from south-western France where some of the oldest known ants lived, corresponded to a moist tropical forest close to the shore with a dominance of gymnosperm trees but where angiosperms (flowering plants) were already diversified. This palaeoenvironmental reconstruction supports an initial radiation of ants in forest ground litter coincident with the rise of angiosperms, as recently proposed as an ecological explanation for their origin and successful evolution.

  16. Lycaenid Caterpillar Secretions Manipulate Attendant Ant Behavior.

    Science.gov (United States)

    Hojo, Masaru K; Pierce, Naomi E; Tsuji, Kazuki

    2015-08-31

    Mutualistic interactions typically involve the exchange of different commodities between species. Nutritious secretions are produced by a number of insects and plants in exchange for services such as defense. These rewards are valuable metabolically and can be used to reinforce the behavior of symbiotic partners that can learn and remember them effectively. We show here novel effects of insect exocrine secretions produced by caterpillars in modulating the behavior of attendant ants in the food-for-defense interaction between lycaenid butterflies and ants. Reward secretions from the dorsal nectary organ (DNO) of Narathura japonica caterpillars function to reduce the locomotory activities of their attendant ants, Pristomyrmex punctatus workers. Moreover, workers that feed from caterpillar secretions are significantly more likely to show aggressive responses to eversion of the tentacle organs of the caterpillars. Analysis of the neurogenic amines in the brains of workers that consumed caterpillar secretions showed a significant decrease in levels of dopamine compared with controls. Experimental treatments in which reserpine, a known inhibitor of dopamine in Drosophila, was fed to workers similarly reduced their locomotory activity. We conclude that DNO secretions of lycaenid caterpillars can manipulate attendant ant behavior by altering dopaminergic regulation and increasing partner fidelity. Unless manipulated ants also receive a net nutritional benefit from DNO secretions, this suggests that similar reward-for-defense interactions that have been traditionally considered to be mutualisms may in fact be parasitic in nature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Fuzzy Rules for Ant Based Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Amira Hamdi

    2016-01-01

    Full Text Available This paper provides a new intelligent technique for semisupervised data clustering problem that combines the Ant System (AS algorithm with the fuzzy c-means (FCM clustering algorithm. Our proposed approach, called F-ASClass algorithm, is a distributed algorithm inspired by foraging behavior observed in ant colonyT. The ability of ants to find the shortest path forms the basis of our proposed approach. In the first step, several colonies of cooperating entities, called artificial ants, are used to find shortest paths in a complete graph that we called graph-data. The number of colonies used in F-ASClass is equal to the number of clusters in dataset. Hence, the partition matrix of dataset founded by artificial ants is given in the second step, to the fuzzy c-means technique in order to assign unclassified objects generated in the first step. The proposed approach is tested on artificial and real datasets, and its performance is compared with those of K-means, K-medoid, and FCM algorithms. Experimental section shows that F-ASClass performs better according to the error rate classification, accuracy, and separation index.

  18. Detection of mitochondrial COII DNA sequences in ant guts as a method for assessing termite predation by ants.

    Science.gov (United States)

    Fayle, Tom M; Scholtz, Olivia; Dumbrell, Alex J; Russell, Stephen; Segar, Simon T; Eggleton, Paul

    2015-01-01

    Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs.

  19. Detection of mitochondrial COII DNA sequences in ant guts as a method for assessing termite predation by ants.

    Directory of Open Access Journals (Sweden)

    Tom M Fayle

    Full Text Available Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1 to 0 % (0/7; Ponera sp. 1, there was no evidence (with small sample sizes for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs.

  20. Desert ants learn vibration and magnetic landmarks.

    Directory of Open Access Journals (Sweden)

    Cornelia Buehlmann

    Full Text Available The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

  1. Kin-informative recognition cues in ants

    DEFF Research Database (Denmark)

    Nehring, Volker; Evison, Sophie E F; Santorelli, Lorenzo A

    2011-01-01

    behaviour is thought to be rare in one of the classic examples of cooperation--social insect colonies--because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have...... found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus. Contrary to the theoretical...... prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential...

  2. Moribund Ants Do Not Call for Help.

    Directory of Open Access Journals (Sweden)

    Krzysztof Miler

    Full Text Available When an antlion captures a foraging ant, the victim's nestmates may display rescue behaviour. This study tested the hypothesis that the expression of rescue behaviour depends on the life expectancy of the captured ant. This hypothesis predicts that the expression of rescue behaviour will be less frequent when the captured ant has a lower life expectancy than when it has a higher life expectancy because such a response would be adaptive at the colony level. Indeed, significant differences were found in the frequency of rescue behaviours in response to antlion victims with differing life expectancies. In agreement with prediction, victims with lower life expectancies were rescued less frequently, and those rescues had a longer latency and shorter duration. There was also a qualitative difference in the behaviour of rescuers to victims from the low and high life expectancy groups. Several explanations for these findings are proposed.

  3. Hopfield neural network based on ant system

    Institute of Scientific and Technical Information of China (English)

    洪炳镕; 金飞虎; 郭琦

    2004-01-01

    Hopfield neural network is a single layer feedforward neural network. Hopfield network requires some control parameters to be carefully selected, else the network is apt to converge to local minimum. An ant system is a nature inspired meta heuristic algorithm. It has been applied to several combinatorial optimization problems such as Traveling Salesman Problem, Scheduling Problems, etc. This paper will show an ant system may be used in tuning the network control parameters by a group of cooperated ants. The major advantage of this network is to adjust the network parameters automatically, avoiding a blind search for the set of control parameters.This network was tested on two TSP problems, 5 cities and 10 cities. The results have shown an obvious improvement.

  4. Ant-plants and fungi: a new threeway symbiosis.

    Science.gov (United States)

    Defossez, Emmanuel; Selosse, Marc-André; Dubois, Marie-Pierre; Mondolot, Laurence; Faccio, Antonella; Djieto-Lordon, Champlain; McKey, Doyle; Blatrix, Rumsaïs

    2009-06-01

    Symbioses between plants and fungi, fungi and ants, and ants and plants all play important roles in ecosystems. Symbioses involving all three partners appear to be rare. Here, we describe a novel tripartite symbiosis in which ants and a fungus inhabit domatia of an ant-plant, and present evidence that such interactions are widespread. We investigated 139 individuals of the African ant-plant Leonardoxa africana for occurrence of fungus. Behaviour of mutualist ants toward the fungus within domatia was observed using a video camera fitted with an endoscope. Fungi were identified by sequencing a fragment of their ribosomal DNA. Fungi were always present in domatia occupied by mutualist ants but never in domatia occupied by opportunistic or parasitic ants. Ants appear to favour the propagation, removal and maintenance of the fungus. Similar fungi were associated with other ant-plants in Cameroon. All belong to the ascomycete order Chaetothyriales; those from L. africana formed a monophyletic clade. These new plant-ant-fungus associations seem to be specific, as demonstrated within Leonardoxa and as suggested by fungal phyletic identities. Such tripartite associations are widespread in African ant-plants but have long been overlooked. Taking fungal partners into account will greatly enhance our understanding of symbiotic ant-plant mutualisms.

  5. An ants-eye view of an ant-plant protection mutualism

    Science.gov (United States)

    Lanan, M. C.; Bronstein, J. L.

    2013-01-01

    Ant protection of extrafloral nectar-secreting plants (EFN plants) is a common form of mutualism found in most habitats around the world. However, very few studies have considered these mutualisms from the ant, rather than the plant, perspective. In particular, a whole-colony perspective that takes into account the spatial structure and nest arrangement of the ant colonies that visit these plants has been lacking, obscuring when and how colony-level foraging decisions might affect tending rates on individual plants. Here, we experimentally demonstrate that recruitment of Crematogaster opuntiae (Buren) ant workers to the extrafloral nectar-secreting cactus Ferocactus wislizeni (Englem) is not independent between plants up to 5m apart. Colony territories of C. opuntiae are large, covering areas of up to 5000m2, and workers visit between five and thirty-four extrafloral nectar-secreting barrel cacti within the territories. These ants are highly polydomous, with up to twenty nest entrances dispersed throughout the territory and interconnected by trail networks. Our study demonstrates that worker recruitment is not independent within large polydomous ant colonies, highlighting the importance of considering colonies rather than individual workers as the relevant study unit within ant/plant protection mutualisms PMID:23515612

  6. The worldwide expansion of the Argentine ant

    DEFF Research Database (Denmark)

    Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana

    2010-01-01

    DNA haplotypes also suggests that supercolonies in the introduced range each derive from a single source supercolony and that one of these source supercolonies has been particularly successful, being the basis of many introduced populations spread across the world. Comparison of the genetic diversity......Aim The aim of this study was to determine the number of successful establishments of the invasive Argentine ant outside native range and to see whether introduced supercolonies have resulted from single or multiple introductions. We also compared the genetic diversity of native versus introduced...... to possible strategies to be used to control invasive ants....

  7. The ejaculatory biology of leafcutter ants

    DEFF Research Database (Denmark)

    den Boer, Susanne; Stürup, Marlene; Boomsma, Jacobus Jan

    2015-01-01

    The eusocial ants are unique in that females (queens) acquire and store sperm on a single mating flight early in adult life. This event largely determines the size (possibly millions of workers), longevity (possibly decades) and genetic variation of the colonies that queens found, but our...... understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip...

  8. Chaotic ant swarm optimization to economic dispatch

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Jiejin; Ma, Xiaoqian [Electric Power College, South China University of Technology, Guangzhou 510640 (China); Li, Lixiang; Yang, Yixian [Information Security Center, Department of Information Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Networking and Switching, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng [Information Security Center, Department of Information Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Networking and Switching, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of Information Science and Engineering, Shenyang University of Technology, Shenyang 110023 (China); Wang, Xiangdong [School of Information Science and Engineering, Shenyang University of Technology, Shenyang 110023 (China)

    2007-08-15

    This paper developed a novel algorithm named chaotic ant swarm optimization (CASO) for solving the economic dispatch (ED) problems of thermal generators in power systems. This algorithm combines with the chaotic and self-organization behavior of ants in the foraging process. It includes both effects of chaotic dynamics and swarm-based search. The algorithm was employed to solve the ED problems of thermal generators. The proposed method was applied to three examples of power systems. Simulation results demonstrated that the method can obtain feasible and effective solutions, and it is a promising alternative approach for solving the ED problems in practical power systems. (author)

  9. Ant functional responses along environmental gradients.

    Science.gov (United States)

    Arnan, Xavier; Cerdá, Xim; Retana, Javier

    2014-11-01

    Understanding species distributions and diversity gradients is a central challenge in ecology and requires prior knowledge of the functional traits mediating species' survival under particular environmental conditions. While the functional ecology of plants has been reasonably well explored, much less is known about that of animals. Ants are among the most diverse, abundant and ecologically significant organisms on earth, and they perform a great variety of ecological functions. In this study, we analyse how the functional species traits present in ant communities vary along broad gradients in climate, productivity and vegetation type in the south-western Mediterranean. To this end, we compiled one of the largest animal databases to date: it contains information on 211 local ant communities (including eight climate variables, productivity, and vegetation type) and 124 ant species, for which 10 functional traits are described. We used traits that characterize different dimensions of the ant functional niche with respect to morphology, life history and behaviour at both individual and colony level. We calculated two complementary functional trait community indices ('trait average' and 'trait dissimilarity') for each trait, and we analysed how they varied along the three different gradients using generalized least squares models that accounted for spatial autocorrelation. Our results show that productivity, vegetation type and, to a lesser extent, each climate variable per se might play an important role in shaping the occurrence of functional species traits in ant communities. Among the climate variables, temperature and precipitation seasonality had a much higher influence on functional responses than their mean values, whose effects were almost lacking. Our results suggest that strong relationships might exist between the abiotic environment and the distribution of functional traits among south-western Mediterranean ant communities. This finding indicates that

  10. 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 easily...... quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up...

  11. Evolution of Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The attine ant symbiosis is characterized by ancient but varying degrees of diffuse co-evolution between the ants and their fungal cultivars. Domesticated fungi became dependent on vertical transmission by queens and the ant colonies came to rely on their symbiotic fungus for food and thus......, indirectly, on fungal enzymes to break down the plant material brought in by the ants as fungal substrate. The more than 210 extant fungus-growing ant species differ considerably in colony size, social complexity and substrate-use. Only the derived leaf-cutting ants are specialized on using fresh leaves...... enzyme activity across ant genera could indeed be partially explained by substrate differences. This implies that fungal enzyme activity has likely coevolved with the genus- or species-specific substrates that the ants use to manure their fungus garden. Plant decomposing enzymes are thus not only...

  12. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging.

    Science.gov (United States)

    Lange, Denise; Calixto, Eduardo Soares; Del-Claro, Kleber

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system.

  13. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging

    Science.gov (United States)

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system. PMID:28046069

  14. Research on the Perceptual Law of Artificial Ants

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zhaobao

    2005-01-01

    Beginning with the analysis of the behavior of natural ants, this paper illuminates the principle and method that, by adopting image texture energy as pheromone and finding their way on the track of the pheromone, artificial ants have the ability to identify and remember through similar measurement of pheromone. Based on the quantity of experiments, this paper analyzes some factors that influence the ability of artificial ants and draws some conclusions about the law of ant perception.

  15. Extended phenotype: nematodes turn ants into bird-dispersed fruits

    DEFF Research Database (Denmark)

    Hughes, D P; Kronauer, D J C; Boomsma, J J

    2008-01-01

    A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs.......A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs....

  16. Dealing with water deficit in Atta ant colonies: large ants scout for water while small ants transport it

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Da-Silva

    2012-07-01

    Leafcutter ants (Atta sexdens rubropilosa (Forel 1908 have an elaborate social organization, complete with caste divisions. Activities carried out by specialist groups contribute to the overall success and survival of the colony when it is confronted with environmental challenges such as dehydration. Ants detect variations in humidity inside the nest and react by activating several types of behavior that enhance water uptake and decrease water loss, but it is not clear whether or not a single caste collects water regardless of the cost of bringing this resource back to the colony. Accordingly, we investigated water collection activities in three colonies of Atta sexdens rubropilosa experimentally exposed to water stress. Specifically, we analyzed whether or not the same ant caste foraged for water, regardless of the absolute energetic cost (distance of transporting this resource back to the colony. Our experimental design offered water sources at 0 m, 1 m and 10 m from the nest. We studied the body size of ants near the water sources from the initial offer of water (time  =  0 to 120 min, and tested for specialization. We observed a reduction in the average size and variance of ants that corroborated the specialization hypothesis. Although the temporal course of specialization changed with distance, the final outcome was similar among distances. Thus, we conclude that, for this species, a specialist (our use of the word “specialist” does not mean exclusive task force is responsible for collecting water, regardless of the cost of transporting water back to the colony.

  17. Ants Orasest ja Anne Lange monograafiast / Jüri Talvet

    Index Scriptorium Estoniae

    Talvet, Jüri, 1945-

    2005-01-01

    Arvustus: Oras, Ants. Luulekool. I, Apoloogia / koostajad Hando Runnel ja Jaak Rähesoo. Tartu : Ilmamaa, 2003 ; Oras, Ants. Luulekool II, Meistriklass. Tartu : Ilmamaa, 2004 ; Lange, Anne. Ants Oras : [kirjandusteadlane, -kriitik ja tõlkija (1900-1982)]. Tartu : Ilmamaa, 2004

  18. Eavesdropping on cooperative communication within an ant-butterfly mutualism

    DEFF Research Database (Denmark)

    Elgar, Mark A.; Nash, David Richard; Pierce, Naomi E.

    2016-01-01

    of the Australian lycaenid butterfly, Jalmenus evagoras, form an obligate association with several species of attendant ants, including Iridomyrmex mayri. Ants protect the caterpillars and pupae, and in return are rewarded with nutritious secretions. Female and male adult butterflies use ants as signals...

  19. Ant-egg cataract. An electron microscopic study

    DEFF Research Database (Denmark)

    Schrøder, H D; Nissen, S H

    1979-01-01

    The ultrastructure of the ant-egg cataractous lens has been studied. Comparison of tissue demineralized by means of EDTA with untreated tissue showed the calcium salts in the ant-eggs to be mostly crystalline. A laminar appearance of the ant-egg seen in EDTA treated material suggested an intermit...

  20. Dynamics of an ant-plant-pollinator model

    Science.gov (United States)

    Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

    2015-03-01

    In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

  1. Mutualistic ants as an indirect defence against leaf pathogens.

    Science.gov (United States)

    González-Teuber, Marcia; Kaltenpoth, Martin; Boland, Wilhelm

    2014-04-01

    Mutualistic ants are commonly considered as an efficient indirect defence against herbivores. Nevertheless, their indirect protective role against plant pathogens has been scarcely investigated. We compared the protective role against pathogens of two different ant partners, a mutualistic and a parasitic ant, on the host plant Acacia hindsii (Fabaceae). The epiphytic bacterial community on leaves was evaluated in the presence and absence of both ant partners by cultivation and by 454 pyrosequencing of the 16S rRNA gene. Pathogen-inflicted leaf damage, epiphytic bacterial abundance (colony-forming units) and number of operational taxonomic units (OTUs) were significantly higher in plants inhabited by parasitic ants than in plants inhabited by mutualistic ants. Unifrac unweighted and weighted principal component analyses showed that the bacterial community composition on leaves changed significantly when mutualistic ants were removed from plants or when plants were inhabited by parasitic ants. Direct mechanisms provided by ant-associated bacteria would contribute to the protective role against pathogens. The results suggest that the indirect defence of mutualistic ants also covers the protection from bacterial plant pathogens. Our findings highlight the importance of considering bacterial partners in ant-plant defensive mutualisms, which can contribute significantly to ant-mediated protection from plant pathogens. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  2. Ants Orasest ja Anne Lange monograafiast / Jüri Talvet

    Index Scriptorium Estoniae

    Talvet, Jüri, 1945-

    2005-01-01

    Arvustus: Oras, Ants. Luulekool. I, Apoloogia / koostajad Hando Runnel ja Jaak Rähesoo. Tartu : Ilmamaa, 2003 ; Oras, Ants. Luulekool II, Meistriklass. Tartu : Ilmamaa, 2004 ; Lange, Anne. Ants Oras : [kirjandusteadlane, -kriitik ja tõlkija (1900-1982)]. Tartu : Ilmamaa, 2004

  3. Are ant feces nutrients for plants? A metabolomics approach to elucidate the nutritional effects on plants hosting weaver ants

    DEFF Research Database (Denmark)

    Vidkjær, Nanna Hjort; Wollenweber, Bernd; Gislum, René

    2015-01-01

    interactions involving other ant species that have demonstrated the transfer of nutrients from ants to plants. In this 7-months study, a GC–MS-based metabolomics approach along with an analysis of total nitrogen and carbon levels was used to study metabolic changes in ant-hosting Coffea arabica plants compared......Weaver ants (genus Oecophylla) are tropical carnivorous ant species living in high numbers in the canopies of trees. The ants excrete copious amounts of fecal matter on leaf surfaces, and these feces may provide nutrients to host trees. This hypothesis is supported by studies of ant-plant...... with control plants. The results showed elevated levels of total nitrogen, amino acids, fatty acids, caffeine, and secondary metabolites of the phenylpropanoid pathway in leaves from ant-hosting plants. Minor effects were observed for sugars, whereas little or no effect was observed for organic acids, despite...

  4. Vestlus päevapoliitikast Ants Vahtrasega / Ants Vahtras ; interv. Hillar Padu

    Index Scriptorium Estoniae

    Vahtras, Ants, 1953-

    2001-01-01

    Keskerakonna Hiiumaa osakonna esimees Ants Vahtras keskendub vestluses Keskerakonna kandidaatidele presidendi valimistele, arutleb presidendile vajalike isikuomaduste, haldusreformi, Hiiumaa Suurkogu, erastamiselt laekuva raha kasutamise üle ning annab hinnangu kultuuripoliitikale. Autor: Keskerakond

  5. Nõunik Ants Laansalu - rohkem talupoeg kui sulane / Ants Laansalu ; interv. Heiki Raudla

    Index Scriptorium Estoniae

    Laansalu, Ants, 1938-2011

    2008-01-01

    Intervjuu põllumajandusministeeriumi nõunikuga, kes vastab küsimustele, mis puudutavad Eesti põllumajandusministreid, põllumehe mainet, põllumajanduse tulevikku Eestis ja maailmas. Vt. samas: Ants Laansalu: CV

  6. Ants ja Jaak / Ants Juske, Jaak Juske ; intervjueerinud Margit Tõnson, Maris Sander

    Index Scriptorium Estoniae

    Juske, Ants, 1956-

    2011-01-01

    Kunstiteadlane Ants Juske ja tema poliitikust poeg Jaak Juske räägivad põlvkondade erinevustest ja konfliktidest, oma poliitilisest identiteedist, haridusest, eeskujudest, huvidest, eluviisidest. Nende eluloolisi andmeid

  7. Ants Veetõusme ja tema valikud / Ants Veetõusme ; interv. Imbi E. Kaljuste

    Index Scriptorium Estoniae

    Veetõusme, Ants, 1949-

    2002-01-01

    Eesti Maksumaksjate Liidu juhatuse esimehe Ants Veetõusme varasemast elust ning praegusest tegevusest EML-i juhi, spordijuhi ja FIE-na. Kommenteerivad Tõnu Anton ja Tiit Nuudi. Tartu linnapea 1991-1993

  8. The worldwide expansion of the Argentine ant

    DEFF Research Database (Denmark)

    Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana;

    2010-01-01

    ) and secondary introductions (from sites with established invasive supercolonies) were important in the global expansion of the Argentine ant. In combination with the similar social organization of colonies in the native and introduced range, this indicates that invasiveness did not evolve recently as a unique...

  9. A global database of ant species abundances

    Science.gov (United States)

    Gibb, Heloise; Dunn, Rob R.; Sanders, Nathan J.; Grossman, Blair F.; Photakis, Manoli; Abril, Silvia; Agosti, Donat; Andersen, Alan N.; Angulo, Elena; Armbrecht, Ingre; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Bruhl, Carsten; Castracani, Cristina; Cerda, Xim; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Ellison, Aaron M.; Enriquez, Martha L.; Fayle, Tom M.; Feener Jr., Donald H.; Fisher, Brian L.; Fisher, Robert N.; Fitpatrick, Matthew C.; Gomez, Cristanto; Gotelli, Nicholas J.; Gove, Aaron; Grasso, Donato A.; Groc, Sarah; Guenard, Benoit; Gunawardene, Nihara; Heterick, Brian; Hoffmann, Benjamin; Janda, Milan; Jenkins, Clinton; Kaspari, Michael; Klimes, Petr; Lach, Lori; Laeger, Thomas; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Luke, Sarah H.; Majer, Jonathan; McGlynn, Terrence P.; Menke, Sean; Mezger, Dirk; Mori, Alessandra; Moses, Jimmy; Munyai, Thinandavha Caswell; Pacheco, Renata; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; Resasco, Julian; Retana, Javier; Silva, Rogerio R.; Sorger, Magdalena D.; Souza, Jorge; Suarez, Andrew V.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Weiser, Michael D.; Yates, Michelle; Parr, Catherine L.

    2017-01-01

    What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of more than 2693 species and 7953 morphospecies from local assemblages collected at 4212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type and degree of disturbance. The aim of compiling this dataset was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardised methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing dataset.

  10. The evolution of invasiveness in garden ants

    DEFF Research Database (Denmark)

    Cremer, Sylvia; Ugelvig, Line Vej; Drijfhout, Falko P

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its ra...

  11. Recognition of social identity in ants

    DEFF Research Database (Denmark)

    Bos, Nick; d'Ettorre, Patrizia

    2012-01-01

    Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend...

  12. Histrionicotoxin alkaloids finally detected in an ant

    DEFF Research Database (Denmark)

    Jones, Tappey H.; Adams, Rachelle Martha Marie; Spande, Thomas F.

    2012-01-01

    Workers of the ant Carebarella bicolor collected in Panama were found to have two major poison-frog alkaloids, cis- and trans-fused decahydroquinolines (DHQs) of the 269AB type, four minor 269AB isomers, two minor 269B isomers, and three isomers of DHQ 271D. For the first time in an ant, however......, the DHQs were accompanied by six histrionicotoxins (HTXs), viz., 283A, 285A, 285B, 285C, 287A, and 287D. This co-occurrence of the HTX and DHQ alkaloids is the usual pattern seen in dendrobatid frogs. This finding contrasts with our earlier study, where workers of a Brazilian ant, Solenopsis (Diplorhoptrum......) sp., were found to have a very similar DHQ complex but failed to show HTXs. Several new DHQ alkaloids of MW 271 (named in the frog as 271G) are reported from the above ants that have both m/z 202 and 204 as major fragment ions, unlike the spectrum seen for the poison-frog alkaloid 271D, which has...

  13. Improving Emergency Management by Modeling Ant Colonies

    Science.gov (United States)

    2015-03-01

    brood. The brood stages include the egg, the larval, and the pupa.27 The brood is dependent on the colony for nourishment and warmth until fully...night for rest and to relocate the colony. The bivouac is what is created when army ants huddle together in a ball instead of building a physical nest

  14. The ejaculatory biology of leafcutter ants

    DEFF Research Database (Denmark)

    den Boer, Susanne; Stürup, Marlene; Boomsma, Jacobus Jan

    2015-01-01

    understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip...

  15. La nueva novela hispanoamericana ante Europa

    Directory of Open Access Journals (Sweden)

    Manuel Zapata Olivella

    1964-01-01

    Full Text Available Hace exactamente medio siglo -1905- Unamuno se burlaba de los escritores hispanoamericanos a quienes consumía el antojo de descubrir a Europa a los europeos en vez de describir lo que tenían ante sus ojos.

  16. Ants recognize foes and not friends.

    Science.gov (United States)

    Guerrieri, Fernando J; Nehring, Volker; Jørgensen, Charlotte G; Nielsen, John; Galizia, C Giovanni; d'Ettorre, Patrizia

    2009-07-01

    Discriminating among individuals and rejecting non-group members is essential for the evolution and stability of animal societies. Ants are good models for studying recognition mechanisms, because they are typically very efficient in discriminating 'friends' (nest-mates) from 'foes' (non-nest-mates). Recognition in ants involves multicomponent cues encoded in cuticular hydrocarbon profiles. Here, we tested whether workers of the carpenter ant Camponotus herculeanus use the presence and/or absence of cuticular hydrocarbons to discriminate between nest-mates and non-nest-mates. We supplemented the cuticular profile with synthetic hydrocarbons mixed to liquid food and then assessed behavioural responses using two different bioassays. Our results show that (i) the presence, but not the absence, of an additional hydrocarbon elicited aggression and that (ii) among the three classes of hydrocarbons tested (unbranched, mono-methylated and dimethylated alkanes; for mono-methylated alkanes, we present a new synthetic pathway), only the dimethylated alkane was effective in eliciting aggression. Our results suggest that carpenter ants use a fundamentally different mechanism for nest-mate recognition than previously thought. They do not specifically recognize nest-mates, but rather recognize and reject non-nest-mates bearing odour cues that are novel to their own colony cuticular hydrocarbon profile. This begs for a reappraisal of the mechanisms underlying recognition systems in social insects.

  17. Caste-specific tyramides from Myrmicine ants

    Science.gov (United States)

    T.H. Jones; H.M. Garrafo; T.F. Spande; N.R. Andriamaharavo; J.S.T. Gorman; A.J. Snyder; A.W. Jeter; J.A. Torres; John W. Daly

    2010-01-01

    Analysis of the extracts of male ants of Monomorium minimum and Monomorium ebeninum by GC-MS and GC-FTIR revealed the presence of tyramides 2 and 4c, for which the structures were established by comparison with synthetic samples. These compounds and their analogues 1 and 3 were also found in males of other Monomorium species, males of Myrmicaria opaciventris, and males...

  18. Ant System Algorithm Research and Its Applications

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, systematic review on Ant System (AS) algorithm research and application is made, and the authors works of introducing As algorithm into continuous space application are summarized. Then the applicability characters of AS in continuous space optimization problems are also discussed.

  19. Enhanced Pest Ant Control with Hydrophobic Bait

    Science.gov (United States)

    Ants occupy every ecological niche in the world where they contribute to the ecosystem, e.g., as scavengers and aerators of the soil. However, when they are transported, usually through human activities, to new locations they have powerful negative impacts on their adopted homeland. Five of the 17 l...

  20. [Tiit-Rein Viitso. Līvõkīel-estikīel-leţkīel sõnārōntõz] / Eberhard Winkler

    Index Scriptorium Estoniae

    Winkler, Eberhard, 1955-

    2013-01-01

    Arvustus: Līvõkīel-estikīel-leţkīel sõnārōntõz = Liivi-eesti-läti sõnaraamat = Lībiešu-igauņu-latviešu vārdnīca / [koostamine:] Tiit-Rein Viitso, [toimetamine ja läti vasted:] Valts Ernštreits. Riga : Latviešu valodas aģentūra ; Tartu : Tartu Ülikool, 2012

  1. [Tiit-Rein Viitso. Līvõkīel-estikīel-leţkīel sõnārōntõz] / Eberhard Winkler

    Index Scriptorium Estoniae

    Winkler, Eberhard, 1955-

    2013-01-01

    Arvustus: Līvõkīel-estikīel-leţkīel sõnārōntõz = Liivi-eesti-läti sõnaraamat = Lībiešu-igauņu-latviešu vārdnīca / [koostamine:] Tiit-Rein Viitso, [toimetamine ja läti vasted:] Valts Ernštreits. Riga : Latviešu valodas aģentūra ; Tartu : Tartu Ülikool, 2012

  2. Ants mediate the structure of phytotelm communities in an ant-garden bromeliad

    OpenAIRE

    Céréghino, Régis; Leroy, Céline; Dejean,Alain; Corbara, Bruno

    2010-01-01

    International audience; The main theories explaining the biological diversity of rain forests often confer a limited understanding of the contribution of interspecific interactions to the observed patterns. We show how two-species mutualisms can affect much larger segments of the invertebrate community in tropical rain forests. Aechmea mertensii (Bromeliaceae) is both a phytotelm (plant-held water) and an ant-garden epiphyte. We studied the influence of its associated ant species (Pachycondyl...

  3. Can the Argentine ant ( Linepithema humile Mayr) replace native ants in myrmecochory?

    Science.gov (United States)

    Gómez, Crisanto; Oliveras, Jordi

    2003-04-01

    We analyse the influence of the Argentine ant ( Linepithema humile Mayr) on the seed dispersal process of the myrmecochorous plants Euphorbia characias, E. biumbellata, Genista linifolia, G. triflora, G. monspessulana and Sarothamnus arboreus. The observations were made in two study plots of Mediterranean cork-oak secondary forest (invaded and non-invaded by L. humile). The presence of L. humile implies the displacement of all native ant species that disperse seeds. Seed transports in the non-invaded zone were carried out by eight ant species. In the invaded zone, L. humile workers removed and transported seeds to the nest. In vertebrate exclusion trials, we observed the same level of seed removal in the invaded and non-invaded zones. Two findings could explain this result. Although mean time to seed localization was higher for native ants (431.7 s) than that for L. humile (150.5 s), the mean proportion of seeds transported after being detected was higher (50.1%) in non-invaded than in invaded (16.8%) zones. The proportion of seeds removed and transported into an ant nest after an ant-seed interaction had dramatically reduced from non-invaded (41.9%) to invaded (7.4%) zones. The levels of seed dispersal by ants found prior to invasion are unlikely to be maintained in invaded zones. However, total replacement of seed dispersal function is possible if contact iteration finally offers similar levels or quantities of seeds reaching the nests. The results obtained confirm that the Argentine ant invasion may affect myrmecochory dramatically in the Mediterranean biome.

  4. Parameters of ante-mortem delirium

    Directory of Open Access Journals (Sweden)

    Deksnyte, Aušra

    2014-02-01

    Full Text Available Objectives. The aim of this study was to investigate the parameters of ante-mortem delirium of the patients in a closed psychiatric institution and to compare them with the ante-mortem psychopathology of the medical patients. Methods. There were 139 medical records of the patients analyzed, who died during the period of 1997-2003 at the in-patient psychiatric institution. The diagnoses were recorded according to the International Classification of Diseases, 10th Revision (ICD-10 criteria. Patients’ data included age, gender, previous psychiatric disorders, current somatic and psychiatric morbidity, and comorbidity. Results. The incidence of delirium was 83,7%. The delirium group included more elder, male persons who were more likely to have dementia and less inclined to depression. Surprisingly the incidence of delirium among non-dementia men was quite high – 76,9%, as compared to non-dementia women – 23,1% (P=0,008. The duration of delirium differed from 1 to 1335 days. Longer delirium was observed among elder than 75 years (87,7, SD 183,9 vs52,6, SD 121,4 days; P=0,019 and dementia (83,6, SD 173,6 vs 13,5, SD 11,6 days; P<0,001 patients, but did not differ in gender groups. Conclusions. Ante-mortem delirium occurred more commonly in more elder and demented patients The duration of ante-mortem delirium was shorter in younger and non-dementia patients. Patients of the psychiatric institution tend to have longer deliriums than medical patients. The patients with depression and the history of alcohol abuse were not likely to get ante-mortem delirium. Before death in many persons hyperactive and mixed delirium transformed into hypoactive.

  5. Interactive effects of soil-dwelling ants, ant mounds and simulated grazing on local plant community composition

    NARCIS (Netherlands)

    Veen, G.F.; Olff, H.

    2011-01-01

    Interactions between aboveground vertebrate herbivores and subterranean yellow meadow ants (Lasius flavus) can drive plant community patterns in grassland ecosystems. Here, we study the relative importance of the presence of ants (L. flavus) and ant mounds under different simulated grazing regimes

  6. Dead ant walking: a myrmecophilous beetle predator uses parasitoid host location cues to selectively prey on parasitized ants.

    Science.gov (United States)

    Mathis, Kaitlyn A; Tsutsui, Neil D

    2016-08-17

    Myrmecophiles (i.e. organisms that associate with ants) use a variety of ecological niches and employ different strategies to survive encounters with ants. Because ants are typically excellent defenders, myrmecophiles may choose moments of weakness to take advantage of their ant associates. This hypothesis was studied in the rove beetle, Myrmedonota xipe, which associates with Azteca sericeasur ants in the presence of parasitoid flies. A combination of laboratory and field experiments show that M. xipe beetles selectively locate and prey upon parasitized ants. These parasitized ants are less aggressive towards beetles than healthy ants, allowing beetles to eat the parasitized ants alive without interruption. Moreover, behavioural assays and chemical analysis reveal that M. xipe are attracted to the ant's alarm pheromone, the same secretion used by the phorid fly parasitoids in host location. This strategy allows beetles access to an abundant but otherwise inaccessible resource, as A. sericeasur ants are typically highly aggressive. These results are the first, to our knowledge, to demonstrate a predator sharing cues with a parasitoid to gain access to an otherwise unavailable prey item. Furthermore, this work highlights the importance of studying ant-myrmecophile interactions beyond just their pairwise context.

  7. Experimental Study of the Dynamics of Foraging Ants

    Science.gov (United States)

    Walker, J. I.; Fetzner, R. P.; Baxter, G. W.

    2006-03-01

    We study the search paths of foraging ants in order to describe their behavior mathematically. Ants have become popular as simple agents in models of artificial life. Here, the ant is presented the problem of finding food when no food cues are present. In this experiment, individual ants (Formicinae lasius flavus) are allowed to forage on a two-dimensional textured surface in the absence of a food source. The position of the ant as a function of time is determined with a high resolution digital camera. The scaling properties of the resulting foraging paths compare favorably with those of certain types of random walk.

  8. Ant species confer different partner benefits on two neotropical myrmecophytes.

    Science.gov (United States)

    Frederickson, Megan E

    2005-04-01

    The dynamics of mutualistic interactions involving more than a single pair of species depend on the relative costs and benefits of interaction among alternative partners. The neotropical myrmecophytes Cordia nodosa and Duroia hirsuta associate with several species of obligately symbiotic ants. I compared the ant partners of Cordia and Duroia with respect to two benefits known to be important in ant-myrmecophyte interactions: protection against herbivores provided by ants, and protection against encroaching vegetation provided by ants. Azteca spp., Myrmelachista schumanni, and Allomerus octoarticulatus demerarae ants all provide the leaves of Cordia and Duroia some protection against herbivores. However, Azteca and Allomerus provide more protection than does Myrmelachista to the leaves of their host plants. Although Allomerus protects the leaves of its hosts, plants occupied by Allomerus suffer more attacks by herbivores to their stems than do plants occupied by other ants. Relative to Azteca or Allomerus, Myrmelachista ants provide better protection against encroaching vegetation, increasing canopy openness over their host plants. These differences in benefits among the ant partners of Cordia and Duroia are reflected in the effect of each ant species on host plant size, growth rate, and reproduction. The results of this study show how mutualistic ant partners can differ with respect to both the magnitude and type of benefits they provide to the same species of myrmecophytic host.

  9. The interactions of ants with their biotic environment

    Science.gov (United States)

    Renner, Susanne S.

    2017-01-01

    This special feature results from the symposium ‘Ants 2016: ant interactions with their biotic environments’ held in Munich in May 2016 and deals with the interactions between ants and other insects, plants, microbes and fungi, studied at micro- and macroevolutionary levels with a wide range of approaches, from field ecology to next-generation sequencing, chemical ecology and molecular genetics. In this paper, we review key aspects of these biotic interactions to provide background information for the papers of this special feature. After listing the major types of biotic interactions that ants engage in, we present a brief overview of ant/ant communication, ant/plant interactions, ant/fungus symbioses, and recent insights about ants and their endosymbionts. Using a large molecular clock-dated Formicidae phylogeny, we map the evolutionary origins of different ant clades' interactions with plants, fungi and hemiptera. Ants' biotic interactions provide ideal systems to address fundamental ecological and evolutionary questions about mutualism, coevolution, adaptation and animal communication. PMID:28298352

  10. The Pied Piper: A Parasitic Beetle's Melodies Modulate Ant Behaviours.

    Directory of Open Access Journals (Sweden)

    Andrea Di Giulio

    Full Text Available Ants use various communication channels to regulate their social organisation. The main channel that drives almost all the ants' activities and behaviours is the chemical one, but it is long acknowledged that the acoustic channel also plays an important role. However, very little is known regarding exploitation of the acoustical channel by myrmecophile parasites to infiltrate the ant society. Among social parasites, the ant nest beetles (Paussus are obligate myrmecophiles able to move throughout the colony at will and prey on the ants, surprisingly never eliciting aggression from the colonies. It has been recently postulated that stridulatory organs in Paussus might be evolved as an acoustic mechanism to interact with ants. Here, we survey the role of acoustic signals employed in the Paussus beetle-Pheidole ant system. Ants parasitised by Paussus beetles produce caste-specific stridulations. We found that Paussus can "speak" three different "languages", each similar to sounds produced by different ant castes (workers, soldiers, queen. Playback experiments were used to test how host ants respond to the sounds emitted by Paussus. Our data suggest that, by mimicking the stridulations of the queen, Paussus is able to dupe the workers of its host and to be treated as royalty. This is the first report of acoustic mimicry in a beetle parasite of ants.

  11. Fast and flexible: argentine ants recruit from nearby trails.

    Science.gov (United States)

    Flanagan, Tatiana P; Pinter-Wollman, Noa M; Moses, Melanie E; Gordon, Deborah M

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  12. Insect navigation: do ants live in the now?

    Science.gov (United States)

    Graham, Paul; Mangan, Michael

    2015-03-01

    Visual navigation is a critical behaviour for many animals, and it has been particularly well studied in ants. Decades of ant navigation research have uncovered many ways in which efficient navigation can be implemented in small brains. For example, ants show us how visual information can drive navigation via procedural rather than map-like instructions. Two recent behavioural observations highlight interesting adaptive ways in which ants implement visual guidance. Firstly, it has been shown that the systematic nest searches of ants can be biased by recent experience of familiar scenes. Secondly, ants have been observed to show temporary periods of confusion when asked to repeat a route segment, even if that route segment is very familiar. Taken together, these results indicate that the navigational decisions of ants take into account their recent experiences as well as the currently perceived environment. © 2015. Published by The Company of Biologists Ltd.

  13. Extrafloral nectar content alters foraging preferences of a predatory ant.

    Science.gov (United States)

    Wilder, Shawn M; Eubanks, Micky D

    2010-04-23

    We tested whether the carbohydrate and amino acid content of extrafloral nectar affected prey choice by a predatory ant. Fire ants, Solenopsis invicta, were provided with artificial nectar that varied in the presence of carbohydrates and amino acids and were then provided with two prey items that differed in nutritional content, female and male crickets. Colonies of fire ants provided with carbohydrate supplements consumed less of the female crickets and frequently did not consume the high-lipid ovaries of female crickets. Colonies of fire ants provided with amino acid supplements consumed less of the male crickets. While a number of studies have shown that the presence of extrafloral nectar or honeydew can affect ant foraging activity, these results suggest that the nutritional composition of extrafloral nectar is also important and can affect subsequent prey choice by predatory ants. Our results suggest that, by altering the composition of extrafloral nectar, plants could manipulate the prey preferences of ants foraging on them.

  14. Fast and Flexible: Argentine Ants Recruit from Nearby Trails

    Science.gov (United States)

    Flanagan, Tatiana P.; Pinter-Wollman, Noa M.; Moses, Melanie E.; Gordon, Deborah M.

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources. PMID:23967129

  15. Fast and flexible: argentine ants recruit from nearby trails.

    Directory of Open Access Journals (Sweden)

    Tatiana P Flanagan

    Full Text Available Argentine ants (Linepithema humile live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  16. Bioturbation by Fire Ants in the Coastal Prairie of Texas

    Science.gov (United States)

    Cameron, G.; Williams, L.

    2001-12-01

    Fire ants (Solenopsis invicta) were introduced to the US in the early part of the last century. They have spread throughout the southeastern US in the absence of native competitors and predators with a range limited by abiotic factors. Each fire ant mound contains thousands of individuals, can be large, and can be numerous enough to comprise a dominant feature of the landscape. Studies of this species have focused upon its spread, formation of single- and multiple-queen colonies, genetic structure, and impact on native fauna and human health. Some studies have analyzed native fire ant-soil interactions, but few studies have examined the process of bioturbation by introduced fire ants in native ecosystems. Fire ants on the coastal prairie of Texas primarily are of the multiple-queen type that exhibit a much higher density of mounds than the single-queen type. Consequently, mound-building activities by fire ants can have a marked effect upon soil structure and nutrient content and may affect soil organisms and plants. Fire ant activity, mound density, mound dispersion, soil texture, soil permeability, soil moisture content, and soil nutrients were measured. Fire ants mounds are visible aboveground from April-November. Density of mounds was 117-738/ha, and average mound lifespan was 3.6 months with only 9% of the mounds remaining active throughout the entire season. Mounds were dispersed randomly. Foraging activity by fire ants was from June through October with a peak in July. Annual soil turnover was estimated by collecting and weighing mounds. There was no effect of ant mounds on soil texture, but water infiltration was higher in areas with ant mounds. Early-season samples showed no nutrient differences, but late-season samples showed that ant mounds contained higher amounts of micronutrients than random samples of soil. These data are compared to similar data on effects of mounds from native ants and from native and introduced ants in different habitats.

  17. Honey Bees Avoiding Ant Harassment at Flowers Using Scent Cues.

    Science.gov (United States)

    Sidhu, Sheena C; Wilson Rankin, Erin E

    2016-02-01

    Pollinators require resources throughout the year to maintain healthy populations. Along the urban-natural interface, floral resource availability may be limited especially when the system experiences extreme drought and fire threats. In such areas, succulents, such as Aloe spp., are commonly planted to serve as functional drought-tolerant, fire-protective landscaping, which can also support pollinator populations. However, access to this resource may be restricted by competition from other floral foragers, including invasive pests. We measured free-foraging honey bee (Apis mellifera L.) visitation rate and visitation duration to aloe flowers with and without Argentine ants (Linepithema humile (Mayr)) in a drought-stressed environment and found that bees actively avoided foraging on the ant-occupied flowers. To determine the mechanisms of avoidance, our subsequent experiments assessed visitation in the absence of ants and compared aloe flowers treated with ant pheromone to unmanipulated flowers lacking ant pheromone. Bees approached all flowers equally, but accepted flowers without ants at a higher rate than flowers with ants. Visitation duration also increased twofold on ant-excluded flowers, which suggests that Argentine ants may limit resource acquisition by bees. Honey bees similarly avoided flowers with Argentine ant pheromone and preferentially visited unmanipulated flowers at threefold higher rate. This study demonstrates that honey bees avoid foraging on floral resources with invasive Argentine ants and that bees use ant odors to avoid ant-occupied flowers. Resource limitation by this invasive pest ant may have serious implication for sustaining healthy pollinator populations at the urban-natural interface. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Absence of population asymmetry in the American Quarter Horse (Equus ferus caballus) performing skilled left and right manoeuvres in reining competition.

    Science.gov (United States)

    Whishaw, Ian Q

    2015-01-01

    Use of the right hand by humans for speech-related hand gestures, writing and throwing exemplifies motoric asymmetry. There are reports of asymmetry in many other animal species, including reports of left preference in emotional responsivity, spontaneous behaviour and the trained performance of the horse, Equus ferus caballus. The present study used the novel approach of using judges' scores to examine asymmetry in an equestrian event. The study analysed the scores of five judges evaluating the reining performance of 482, three-year-old American Quarter Horses competing in a major competition. Reining requires that the horses perform the manoeuvres of spin, circle and stop directed to either the left or right and symmetrical performance is featured in the judging criteria. The scores were sensitive to performance level, sex and manoeuvre, but there was no evidence of a population asymmetry in the left vs. right direction of the manoeuvres. The results are discussed in relation to need of using a large number of subjects in measuring asymmetry, the expression of individual vs. population asymmetry as a function of morphological and behavioural measures, and the influence of behavioural training on asymmetry.

  19. The mane effect in the horse (Equus ferus caballus): Right mane dominance enhanced in mares but not associated with left and right manoeuvres in a reining competition.

    Science.gov (United States)

    Whishaw, Ian Q; Kolb, Bryan

    2017-07-01

    A human physical asymmetry is the near 90% clockwise occipitoparietal scalp hair-whorl direction in Europeans, an incidence that approximates the left lateralization of speech and right-handedness. Hair-whorl direction is also asymmetric in horses, Equus ferus caballus and placement is proposed to be related to temperament and lateralized skill in equitation manoeuvres. We describe a hair-whorl asymmetry in the horse, mane direction. Of 526, 3-year-old American Quarter horses, 69% of horses had mane directed to the right and 31% had mane directed to the left. The bias was larger in females, with 74% of females vs. 65% of males having mane directed to the right. Mane direction was unrelated to coat colour. The behavioural significance of mane asymmetry was investigated using judges' scores from a reining competition requiring symmetrical maneuvers of spin, circle and roll-back to either the left or to the right. There was no relation between mane asymmetry and overall reining performance and no relation between mane direction and scores for left or right manoeuvres. The results are discussed in relation to the significance of morphological asymmetries, neural function and the influence of planar cell polarity genes, such as Frizzled, that influence epidermal hair cell patterning.

  20. Interaction between Mutualisms: Ant-tended butterflies exploit enemy-free space provided by ant-treehopper associations.

    Science.gov (United States)

    Kaminski, Lucas A; Freitas, André V L; Oliveira, Paulo S

    2010-09-01

    Although mutualisms have been intensively investigated, demonstration of indirect effects between co-occurring mutualistic systems is rare. For instance, the ecological consequences of co-occurrence of ant-tended insects on a plant have never been examined for survival effects on either trophobiont species. Here, we assess the selective pressures mediating co-occurrence of a facultative ant-tended butterfly (Parrhasius polibetes) with ant-tended treehoppers (Guayaquila xiphias) on Schefflera vinosa shrubs. We evaluated host plant selection and caterpillar survival in P. polibetes in the presence and absence of ant-treehopper associations. Paired trials revealed that butterflies preferably oviposit on branches hosting ant-tended treehoppers when they had a choice between those and branches without this interaction. Presence of ant-tended treehoppers on a branch reduced the abundance of P. polibetes' natural enemies and improved caterpillar survival in both premyrmecophylic and ant-tended phases. Thus ant-tended treehoppers create an enemy-free space on foliage that butterflies exploit to protect larval offspring. These findings connect two widely documented ant-trophobiont mutualisms and highlight the importance of considering multiple interactions for a proper understanding of ant-plant-herbivore systems. Detection of other ant-based mutualisms on oviposition to improve offspring survival may have represented an important evolutionary step in the process of host plant selection in facultative myrmecophilous butterflies.

  1. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem.

    Science.gov (United States)

    Stuble, Katharine L; Kirkman, L Katherine; Carroll, C Ronald; Sanders, Nathan J

    2011-06-01

    The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable.

  2. Ant foraging on extrafloral nectaries of Qualea grandiflora (Vochysiaceae) in cerrado vegetation: ants as potential antiherbivore agents.

    Science.gov (United States)

    Oliveira, P S; da Silva, A F; Martins, A B

    1987-12-01

    Qualea grandiflora is a typical tree of Brazilian cerrados (savanna-like vegetation) that bears paired extrafloral nectaries (EFNs) along its stems. Results show that possession of EFNs increases ant density on Q. grandiflora shrubs over that of neighbouring non-nectariferous plants. Frequency of ant occupancy and mean number of ants per plant were much higher on Qualea than on plants lacking EFNs. These differences resulted in many more live termitebaits being attacked by foraging ants on Qualea than on neighbours without EFNs. Termites were attacked in equal numbers and with equal speeds on different-aged leaves of Qualea. The greatest potential for herbivore deterrence was presented by Camponotus ants (C. crassus, C. rufipes and C. aff. blandus), which together attacked significantly more termites than nine other ant species grouped. EFNs are regarded as important promoters of ant activity on cerado plants.

  3. A plant needs ants like a dog needs fleas: Myrmelachista schumanni ants gall many tree species to create housing.

    Science.gov (United States)

    Edwards, David P; Frederickson, Megan E; Shepard, Glenn H; Yu, Douglas W

    2009-11-01

    Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Although we now know that domatia are not galls and that most ant-plant interactions are mutualisms and not parasitisms, we revisit Spruce's suggestion that ants can gall in light of our observations of the plant-ant Myrmelachista schumanni, which creates clearings in the Amazonian rain forest called "supay-chakras," or "devil's gardens." We observed swollen scars on the trunks of nonmyrmecophytic canopy trees surrounding supay-chakras, and within these swellings, we found networks of cavities inhabited by M. schumanni. Here, we summarize the evidence supporting the hypothesis that M. schumanni ants make these galls, and we hypothesize that the adaptive benefit of galling is to increase the amount of nesting space available to M. schumanni colonies.

  4. Recognition of social identity in ants

    DEFF Research Database (Denmark)

    Bos, Nick; d'Ettorre, Patrizia

    2012-01-01

    Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend o...... is formed, where in the nervous system it is localized, and the possible role of learning. We combine seemingly contradictory evidence in to a novel, parsimonious theory for the information processing of nestmate recognition cues.......Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend...

  5. Ant Colony Optimization and Hypergraph Covering Problems

    CERN Document Server

    Pat, Ankit

    2011-01-01

    Ant Colony Optimization (ACO) is a very popular metaheuristic for solving computationally hard combinatorial optimization problems. Runtime analysis of ACO with respect to various pseudo-boolean functions and different graph based combinatorial optimization problems has been taken up in recent years. In this paper, we investigate the runtime behavior of an MMAS*(Max-Min Ant System) ACO algorithm on some well known hypergraph covering problems that are NP-Hard. In particular, we have addressed the Minimum Edge Cover problem, the Minimum Vertex Cover problem and the Maximum Weak- Independent Set problem. The influence of pheromone values and heuristic information on the running time is analysed. The results indicate that the heuristic information has greater impact towards improving the expected optimization time as compared to pheromone values. For certain instances of hypergraphs, we show that the MMAS* algorithm gives a constant order expected optimization time when the dominance of heuristic information is ...

  6. Optic disc detection using ant colony optimization

    Science.gov (United States)

    Dias, Marcy A.; Monteiro, Fernando C.

    2012-09-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

  7. Comparative analysis of the macronutrient content of Central European ants (Formicidae): implications for ant-eating predators.

    Science.gov (United States)

    Pekár, S; Mayntz, D

    2014-03-01

    Prey nutrient quality determines predator performance. Polyphagous predators can address nutritional challenges by targeting prey with specific nutrient composition, but prey-specialised predators (e.g., ant-eaters), must obtain all nutrients from limited array of prey. Analysis of published data on prey specificity of European ant-eating spiders showed that some feed only on one ant genus, while others feed on several genera. Spiders feeding on several ant genera can possibly balance nutrient intake by selecting different ant prey. But monophagous species must extract all prey from a single prey species and can only vary nutrient intake by feeding on specific body parts. Most ant-eating spider species are catching Formica, Lasius and Messor ants, suggesting that these are most profitable ant species. We evaluated the nutritional content of a variety of 16 Central European ant species belonging to 11 genera and four subfamilies. We found that the nutritional composition, namely the amount of carbon, nitrogen and lipids, of European ants is heterogeneous. The largest variation in the amount of carbon and lipids was among ant subfamilies and species, while the largest variation in nitrogen was among ant genera. The largest amount of carbon and nitrogen was typical for Myrmicinae and the largest amount of lipids were typical for Formicinae. Within ants, the relative amounts of lipids were significantly higher in the gaster while the contents of carbon and nitrogen were highest in foreparts. Ant species did not cluster in the ordination space according to their taxonomic relationship or trophic strategy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. How load-carrying ants avoid falling over: mechanical stability during foraging in Atta vollenweideri grass-cutting ants.

    Directory of Open Access Journals (Sweden)

    Karin Moll

    Full Text Available BACKGROUND: Foraging workers of grass-cutting ants (Atta vollenweideri regularly carry grass fragments larger than their own body. Fragment length has been shown to influence the ants' running speed and thereby the colony's food intake rate. We investigated whether and how grass-cutting ants maintain stability when carrying fragments of two different lengths but identical mass. PRINCIPAL FINDINGS: Ants carried all fragments in an upright, backwards-tilted position, but held long fragments more vertically than short ones. All carrying ants used an alternating tripod gait, where mechanical stability was increased by overlapping stance phases of consecutive steps. The overlap was greatest for ants carrying long fragments, resulting in more legs contacting the ground simultaneously. For all ants, the projection of the total centre of mass (ant and fragment was often outside the supporting tripod, i.e. the three feet that would be in stance for a non-overlapping tripod gait. Stability was only achieved through additional legs in ground contact. Tripod stability (quantified as the minimum distance of the centre of mass to the edge of the supporting tripod was significantly smaller for ants with long fragments. Here, tripod stability was lowest at the beginning of each step, when the center of mass was near the posterior margin of the supporting tripod. By contrast, tripod stability was lowest at the end of each step for ants carrying short fragments. Consistently, ants with long fragments mainly fell backwards, whereas ants carrying short fragments mainly fell forwards or to the side. Assuming that transporting ants adjust neither the fragment angle nor the gait, they would be less stable and more likely to fall over. CONCLUSIONS: In grass-cutting ants, the need to maintain static stability when carrying long grass fragments has led to multiple kinematic adjustments at the expense of a reduced material transport rate.

  9. Polyethism in a colony of artificial ants

    CERN Document Server

    Marriott, Chris

    2011-01-01

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

  10. Ant colony optimization and constraint programming

    CERN Document Server

    Solnon, Christine

    2013-01-01

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

  11. Hommikuti peab sul olema suurim soov teatrisse tulla ja tööpäeva lõpus peab sul olema suurim soov koju minna / Rein Neimar ; intervjueerinud Triin Sinissaar

    Index Scriptorium Estoniae

    Neimar, Rein

    2011-01-01

    Intervjuu Tallinna Linnateatri asedirektori Rein Neimariga, kes tähistas 24. märtsil oma 60. sünnipäeva. Leningradi õppima minekust, teatritööst kui kollektiivsest tööst, teatriimest, sellest, mida teater on talle andnud jm.

  12. Exploration versus exploitation in polydomous ant colonies.

    Science.gov (United States)

    Cook, Zoe; Franks, Daniel W; Robinson, Elva J H

    2013-04-21

    In socially foraging species resource information can be shared between individuals, increasing foraging success. In ant colonies, nestmate recruitment allows high exploitation rates at known resources however, to maximise foraging efficiency this must be balanced with searching for new resources. Many ant species form colonies inhabiting two or more spatially separated but socially connected nests: this type of organisation is known as polydomy. Polydomous colonies may benefit from increased foraging efficiency by carrying out dispersed-central place foraging. However, decentralisation of the colony may affect recruitment success by limiting interaction between ants based in separate nests. We use an agent-based model which compares the foraging success of monodomous and polydomous colonies in different food environments, incorporating recruitment through pheromone trails and group foraging. In contrast to previous results we show that polydomy is beneficial in some but not all cases. Polydomous colonies discover resources at a higher rate, making them more successful when food is highly dispersed, but their relative success can be lowered by limitations on recruitment success. Monodomous colonies can have higher foraging efficiency than polydomous colonies by exploiting food more rapidly. The results show the importance of interactions between recruitment strategy, colony size, and colony organisation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. El periodista, ante la espiral de silencio

    Directory of Open Access Journals (Sweden)

    Dr. Fermín Galindo Arranz

    1998-01-01

    Full Text Available La percepción de la profesión periodística y de su influencia cambia mucho a lo largo del tiempo, de las coyunturas históricas y de los diferentes países y sociedades en los que desempeñan su labor. En un contexto mundial, la gravedad de las situaciones de riesgo periodístico se encuadran en situaciones políticas, económicas o sociales también conflictivas; es entonces cuando se suele reproducir con facilidad en la opinión pública el fenómeno de la espiral del silencio, ante el que inevitablemente se sitúa el periodista. Por definición, el trabajo del periodista consiste en ser portavoz de las novedades que se producen, en dar informaciones y emitir opiniones en la esfera pública, se tiene que situar, por tanto, de forma individual y notoriamente pública ante los fenómenos de espiral de silencio que puedan producirse en la opinión pública. Antonio Tabucchi nos presenta en su novela "Sostiene Pereira" un ejemplo magnífico del dilema del periodista ante este tipo de situaciones.

  14. Indirect defense in a highly specific ant-plant mutualism.

    Science.gov (United States)

    Grangier, Julien; Dejean, Alain; Malé, Pierre-Jean G; Orivel, Jérôme

    2008-10-01

    Although associations between myrmecophytes and their plant ants are recognized as a particularly effective form of protective mutualism, their functioning remains incompletely understood. This field study examined the ant-plant Hirtella physophora and its obligate ant associate Allomerus decemarticulatus. We formulated two hypotheses on the highly specific nature of this association: (1) Ant presence should be correlated with a marked reduction in the amount of herbivory on the plant foliage; (2) ant activity should be consistent with the "optimal defense" theory predicting that the most vulnerable and valuable parts of the plant are the best defended. We validated the first hypothesis by demonstrating that for ant-excluded plants, expanding leaves, but also newly matured ones in the long term, suffered significantly more herbivore damage than ant-inhabited plants. We showed that A. decemarticulatus workers represent both constitutive and inducible defenses for their host, by patrolling its foliage and rapidly recruiting nestmates to foliar wounds. On examining how these activities change according to the leaves' developmental stage, we found that the number of patrolling ants dramatically decreased as the leaves matured, while leaf wounds induced ant recruitment regardless of the leaf's age. The resulting level of these indirect defenses was roughly proportional to leaf vulnerability and value during its development, thus validating our second hypothesis predicting optimal protection. This led us to discuss the factors influencing ant activity on the plant's surface. Our study emphasizes the importance of studying both the constitutive and inducible components of indirect defense when evaluating its efficacy and optimality.

  15. The use of weaver ants (Oecophylla spp.) in tropical agriculture

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim

    2011-01-01

    Canopy dwelling weaver ants are widely distributed throughout the Old World Tropics where they build up high densities on their host trees. If managed properly the high number of ants will control a range of pest insects and benefit crop production. Simultaneously the ant larvae production, fuell...... be sustainable combined with their use in biocontrol, (ii) estimates of ant harvest yields from a mango plantation and (iii) how active feeding of ants may generate economic returns between 1.52 and 4.56 in a Thai market....... into a valuable and needed source of protein. Protein from conventional livestock production leave a high pressure on the environment as the food and farm area needed to produce each protein unit is high. For insect production these requirements are much lower and FAO has recently proposed research in insect...... farming as a way forward to solve an increasing future demand for protein. Weaver ant farming may build on natural food collected by the ants or alternatively be boosted by feeding the ant colonies actively with protein and sugar. In both cases, when ant biocontrol is combined with ant farming...

  16. Chemically armed mercenary ants protect fungus-farming societies.

    Science.gov (United States)

    Adams, Rachelle M M; Liberti, Joanito; Illum, Anders A; Jones, Tappey H; Nash, David R; Boomsma, Jacobus J

    2013-09-24

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies.

  17. Ants at Plant Wounds: A Little-Known Trophic Interaction with Evolutionary Implications for Ant-Plant Interactions.

    Science.gov (United States)

    Staab, Michael; Fornoff, Felix; Klein, Alexandra-Maria; Blüthgen, Nico

    2017-09-01

    Extrafloral nectaries (EFNs) allow plants to engage in mutualisms with ants, preventing herbivory in exchange for food. EFNs occur scattered throughout the plant phylogeny and likely evolved independent from herbivore-created wounds subsequently visited by ants collecting leaked sap. Records of wound-feeding ants are, however, anecdotal. By surveying 38,000 trees from 40 species, we conducted the first quantitative ecological study of this overlooked behavior. Ant-wound interactions were widespread (0.5% of tree individuals) and occurred on 23 tree species. Interaction networks were opportunistic, closely resembling ant-EFN networks. Fagaceae, a family lacking EFNs, was strongly overrepresented. For Fagaceae, ant occurrence at wounds correlated with species-level leaf damage, potentially indicating that wounds may attract mutualistic ants, which supports the hypothesis of ant-tended wounds as precursors of ant-EFN mutualisms. Given that herbivore wounds are common, wound sap as a steadily available food source might further help to explain the overwhelming abundance of ants in (sub)tropical forest canopies.

  18. How Load-Carrying Ants Avoid Falling Over: Mechanical Stability during Foraging in Atta vollenweideri Grass-Cutting Ants

    Science.gov (United States)

    Moll, Karin; Roces, Flavio; Federle, Walter

    2013-01-01

    Background Foraging workers of grass-cutting ants (Atta vollenweideri) regularly carry grass fragments larger than their own body. Fragment length has been shown to influence the ants’ running speed and thereby the colony’s food intake rate. We investigated whether and how grass-cutting ants maintain stability when carrying fragments of two different lengths but identical mass. Principal Findings Ants carried all fragments in an upright, backwards-tilted position, but held long fragments more vertically than short ones. All carrying ants used an alternating tripod gait, where mechanical stability was increased by overlapping stance phases of consecutive steps. The overlap was greatest for ants carrying long fragments, resulting in more legs contacting the ground simultaneously. For all ants, the projection of the total centre of mass (ant and fragment) was often outside the supporting tripod, i.e. the three feet that would be in stance for a non-overlapping tripod gait. Stability was only achieved through additional legs in ground contact. Tripod stability (quantified as the minimum distance of the centre of mass to the edge of the supporting tripod) was significantly smaller for ants with long fragments. Here, tripod stability was lowest at the beginning of each step, when the center of mass was near the posterior margin of the supporting tripod. By contrast, tripod stability was lowest at the end of each step for ants carrying short fragments. Consistently, ants with long fragments mainly fell backwards, whereas ants carrying short fragments mainly fell forwards or to the side. Assuming that transporting ants adjust neither the fragment angle nor the gait, they would be less stable and more likely to fall over. Conclusions In grass-cutting ants, the need to maintain static stability when carrying long grass fragments has led to multiple kinematic adjustments at the expense of a reduced material transport rate. PMID:23300994

  19. Behavior of Ants Escaping from a Single-Exit Room

    Science.gov (United States)

    Wang, Shujie; Lv, Wei; Song, Weiguo

    2015-01-01

    To study the rules of ant behavior and group-formation phenomena, we examined the behaviors of Camponotus japonicus, a species of large ant, in a range of situations. For these experiments, ants were placed inside a rectangular chamber with a single exit that also contained a filter paper soaked in citronella oil, a powerful repellent. The ants formed several groups as they moved toward the exit to escape. We measured the time intervals between individual escapes in six versions of the experiment, each containing an exit of a different width, to quantify the movement of the groups. As the ants exited the chamber, the time intervals between individual escapes changed and the frequency distribution of the time intervals exhibited exponential decay. We also investigated the relationship between the number of ants in a group and the group flow rate. PMID:26125191

  20. Where and how Argentine ant (Linepithema humile) spreads in Corsica?

    Science.gov (United States)

    Blight, Olivier; Orgeas, Jérôme; Renucci, Marielle; Tirard, Alain; Provost, Erick

    2009-08-01

    The Argentine ant, Linepithema humile (Dolichoderinae), is one of the most widespread invasive ant species in the world. When established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. Although Argentine ants have been present in southern Europe for more than 100 years, they were first noted in Corsica, a French Mediterranean island, in 1957 in only one urban station. In this study, we aimed to map precisely their geographical distribution in Corsica and to quantify their presence by using an infestation index. We recorded changes in the distribution of Argentine ants in Corsica over the past decade. Argentine ants appeared to be well established within their introduced range and spreading along the Corsican coasts principally through Human-mediated jump-dispersal but not homogenously.

  1. A Theoretic Basis for IS? The Contribution of ANT

    Directory of Open Access Journals (Sweden)

    Jim Underwood

    2002-11-01

    Full Text Available Representation is a key issue of IS design and operation that is often ignored. Actor-network theory (ANT, a semiotic theory of stakeholders, provides a way of dealing with representation. Combining aspects of ANT and Foucault's discourse theory allows us to include concepts as actors and promises a flexible and durable foundation for IS practice, but ANT itself indicates that the search for a purely theoretical foundation for IS is misguided.

  2. Do herbivores eavesdrop on ant chemical communication to avoid predation?

    Directory of Open Access Journals (Sweden)

    David J Gonthier

    Full Text Available Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis, I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis, exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min. revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus, ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants.

  3. Cercomacra and related antbirds (Aves, Formicariidae as army ant followers

    Directory of Open Access Journals (Sweden)

    Edwin O. Willis

    1984-01-01

    Full Text Available Cercomacra and Schistocichla antbirds (Formicariidae favor dense foliage and seldom follow army ants for flushed prey, since the ants move through open forest understory as well as through dense zones. Two other lineages, the Drymophila-Hypocnemis lineage (of dense woodland understory and the Formicivora lineage (of dense bushes in dry or semiopen zones, also cannot follow ants regularly through open forest understory.

  4. Consuming fire ants reduces northern bobwhite survival and weight gain

    Science.gov (United States)

    Myers, P.E.; Allen, Craig R.; Birge, Hannah E.

    2014-01-01

    Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein source, making it difficult to disentangle their net effect on bobwhite chicks. To help investigate these effects, we conducted a laboratory experiment to understand (1) whether or not bobwhites consume fire ants, and (2) how the benefits of this consumption compare to the deleterious impacts of bobwhite chick exposure to fire ants. Sixty bobwhite chicks were separated into two groups of 30; one group was provided with starter feed only and the second group was provided with feed and fire ants. Bobwhite chicks were observed feeding on fire ants. Chicks that fed on fire ants had reduced survival and weight gain. Our results show that, while fire ants increase potential food sources for northern bobwhite, their net effect on bobwhite chicks is deleterious. This information will help inform land managers and commercial bobwhite rearing operations.

  5. Ant behaviour and seed morphology: a missing link of myrmecochory.

    Science.gov (United States)

    Gómez, Crisanto; Espadaler, Xavier; Bas, Josep M

    2005-12-01

    Seed dispersal by ants (myrmecochory) is mediated by the presence of a lipid-rich appendage (elaiosome) on the seed that induces a variety of ants to collect the diaspores. When seeds mature or fall onto the ground, these ant species transport them to their nest. After eating the elaiosome, the seed is discarded in nest galleries or outside, in the midden or farther away, where seeds can potentially germinate. The final location of seeds with their elaiosomes removed was evaluated to assess the importance of possible handles (structures that ants can grasp to carry) in transporting ants during re-dispersal experiments of seeds from nests of six species of ants. The results indicate that seeds remained within the nest because the ants were not able to transport them out of the nest. As a consequence of the elaiosome being removed, small ant species could not take Euphorbia characias seeds out of their nests. Only large ant species could remove E. characias seeds from their nests. Attaching an artificial handle to E. characias seeds allowed small ant species to redistribute the seeds from their nests. On the other hand, Rhamnus alaternus seeds that have a natural handle after the elaiosome removal were removed from the nests by both groups of ant species. If a seed has an element that acts as a handle, it will eventually get taken out of the nest. The ants' size and their mandible gap can determine the outcome of the interaction (i.e. the pattern of the final seed shadow) and as a consequence, could influence the events that take place after the dispersal process.

  6. Parallelizing Ant Colony Optimization via Area of Expertise Learning

    Science.gov (United States)

    2007-09-13

    lutions for all but the most trivial instances. Ant colony optimization (ACO) is a simple metaheuristic that can effectively solve problems in these...expertise” technique is applied to two problem domains: gridworld and the traveling salesman problem. 1.1 Motivation ACO is a metaheuristic that generates...independent ant agents, an obvious extension of the ant colony framework is to implement the algorithm in a parallel environment. One of the main

  7. Evolutionarily advanced ant farmers rear polyploid fungal crops

    OpenAIRE

    Pepijn W Kooij; Aanen, D. K.; Schiøtt, M.; Boomsma, Jacobus J.

    2015-01-01

    Abstract Innovative evolutionary developments are often related to gene or genome duplications. The crop fungi of attine fungus‐growing ants are suspected to have enhanced genetic variation reminiscent of polyploidy, but this has never been quantified with cytological data and genetic markers. We estimated the number of nuclei per fungal cell for 42 symbionts reared by 14 species of Panamanian fungus‐growing ants. This showed that domesticated symbionts of higher attine ants are polykaryotic ...

  8. Does Trichomes on the Plant Epidermic Surface Disturb Ants Locomotion?

    OpenAIRE

    Danon C. Cardoso; Maykon P Cristiano; Lenise C. M. Vilela; Tiago D. A. Martins

    2009-01-01

    Problem Statement: Many morphological characteristics, both physical and chemical, are used in the defense against herbivores on plants. Trichomes are structures used by plants as physics defense and when associated with glands combine physics and chemistry defense. Many species of ants are herbivores and use leaves and seeds, others ants use Extra Floral Nectars as a food resource, and the majority of the species are predators of other ants and other insects, &#...

  9. Rhabdomyolysis and Acute Renal Failure After Fire Ant Bites

    OpenAIRE

    Koya, Supriya; Crenshaw, Daryl; Agarwal, Anupam

    2007-01-01

    We describe a 59-year-old patient who developed acute renal failure because of rhabdomyolysis after extensive red fire ant bites. This case illustrates a serious systemic reaction that may occur from fire ant bites. Consistent with the clinical presentation in rhabdomyolysis associated with non-traumatic causes, hyperkalemia, hypophosphatemia, hypocalcemia, and high anion gap acidosis were not observed in this patient. While local allergic reactions to fire ant bites are described in the lite...

  10. [Syagrus romanzoffiana (Arecaceae) seed utilization by ants in a secondary forest in South Brazil].

    Science.gov (United States)

    Silva, Fernanda R; Begnini, Romualdo M; Klier, Vinícius A; Scherer, Karla Z; Lopes, Benedito C; Castellani, Tânia T

    2009-01-01

    Ants can nest in a wide variety of substracts. This paper shows Syagrus romanzoffiana seed utilization by ants in an Atlantic secondary forest. We report 29 seeds occupied by small-bodied ants, with 27 of them showing at least two ant development stages. Although a large number of seeds were sampled, a low level of ant occupation was observed.

  11. Laboratory host specificicty testing of the fire ant microsporidian pathogen Vairimorpha invictae (Microsporidia: Burenellidae)

    Science.gov (United States)

    The host specificity of Vairimorpha invictae, a microsporidian pathogen of fire ants in South America, was assessed in the laboratory with the tropical fire ant, Solenopsis geminata, the southern fire ant, Solenopsis xyloni, and the Argentine ant, Linepithema humile. The two fire ant species are fo...

  12. Long-term persistence of a neotropical ant-plant population in the absence of obligate plant-ants.

    Science.gov (United States)

    Moraes, Sinara C; Vasconcelos, Heraldo L

    2009-09-01

    Interactions between ants and ant-plants are considered classic examples of obligate mutualisms. Previous studies have indicated that for many ant-plants the loss of ant colonies results in severe defoliation or mortality. Although individual plants can persist for some period of time without their mutualistic partners, to date populations of ant-free plants have only been recorded at high altitudes or on remote islands where herbivores are also scarce. We studied the interaction between ants, herbivores, and the ant-plant Tococa guianensis in the Cerrado region of central Brazil. Using a survey conducted across a large geographic region, we show that there is interpopulation variation in ant occupancy across sites and habitats. At most sites surveyed, plants were inhabited by Allomerus octoarticulatus, an obligate plant-ant. Plants with obligate ants had significantly lower standing levels of herbivore damage than plants with opportunistic ants and plants with no ant occupants. Furthermore, experimental removal of A. octoarticulatus resulted in increased levels of damage in both young and mature leaves. Despite the protection provided by obligate ants, populations of T. guianensis were found to persist without these ants in some areas. Plants without A. octoarticulatus had significantly greater leaf toughness and trichome density than those with A. octoarticulatus. Furthermore, trichome density in plants with A. octoarticulatus increased after ants were removed, probably as a response induced by increased levels of herbivore damage. To our knowledge, this is the first record of the occurrence of native myrmecophyte populations without their mutualistic ants in mainland low-elevation sites. Several factors may help to explain the long-term persistence of T. guianensis populations without plant-ants in some areas of the Brazilian Cerrado, including its potential for induced morphological defenses against insect herbivores and selection for increased levels of

  13. Stabilit\\'e orbitale pour le syst\\`eme de Vlasov-Poisson gravitationnel, d'apr\\`es Lemou-M\\'ehats-Rapha\\"el, Guo, Lin, Rein et al. [Orbital stability for the gravitational Vlasov-Poisson system, after Lemou-M\\'ehats-Rapha\\"el, Guo, Lin, Rein et al.

    CERN Document Server

    Mouhot, Clément

    2012-01-01

    This paper reviews the recent mathematical progresses made on the study of the orbital stability properties for the gravitational Vlasov-Poisson system. We present in details the paper of Lemou, M\\'ehats and Rapha\\"el (Inventiones 2011) and we review also the previous works by Dolbeault, Guo, Hadzic, Lin, Rein, S\\'anchez, Soler, Wan, Wolansky. We also include a discussion of the history of this topic and the pioneering works by physicists like Antonov, Lynden-Bell and Aly. This is the text of a Bourbaki seminar given in november 2011 (in french).

  14. Ant-Crypto, a Cryptographer for Data Encryption Standard

    Directory of Open Access Journals (Sweden)

    Salabat Khan

    2013-01-01

    Full Text Available Swarm Intelligence and Evolutionary Techniques are attracting the cryptanalysts in the field of cryptography. This paper presents a novel swarm based attack called Ant-Crypto (Ant-Cryptographer for the cryptanalysis of Data Encryption Standard (DES. Ant-Crypto is based on Binary Ant Colony Optimization (BACO i.e. a binary search space based directed graph is modeled for efficiently searching the optimum result (an original encryption key, in our case. The reason that why evolutionary techniques are becoming attractive is because of the inapplicability of traditional techniques and brute force attacks against feistel ciphers due to their inherent structure based on high nonlinearity and low autocorrelation. Ant-Crypto uses a known-plaintext attack to recover the secret key of DES which is required to break/ decipher the secret messages. Ant-Crypto iteratively searches for the secret key while generating several candidate optimum keys that are guessed across different runs on the basis of routes completed by ants. These optimum keys are then used to find each individual bit of the 56 bit secret key used during encryption by DES. Ant-Crypto is compared with some other state of the art evolutionary based attacks i.e. Genetic Algorithm and Comprehensive Binary Particle Swarm Optimization. The experimental results show that Ant-Crypto is an effective evolutionary attack against DES and can deduce large number of valuable bits as compared to other evolutionary algorithms; both in terms of time and space complexity.

  15. Disease dynamics in a specialized parasite of ant societies

    DEFF Research Database (Denmark)

    Andersen, Sandra Breum; Ferrari, Matthew; Evans, Harry C.

    2012-01-01

    Coevolution between ant colonies and their rare specialized parasites are intriguing, because lethal infections of workers may correspond to tolerable chronic diseases of colonies, but the parasite adaptations that allow stable coexistence with ants are virtually unknown. We explore the trade......-offs experienced by Ophiocordyceps parasites manipulating ants into dying in nearby graveyards. We used field data from Brazil and Thailand to parameterize and fit a model for the growth rate of graveyards. We show that parasite pressure is much lower than the abundance of ant cadavers suggests...

  16. Ant plant herbivore interactions in the neotropical cerrado savanna

    Science.gov (United States)

    Oliveira, Paulo S.; Freitas, André V. L.

    2004-12-01

    The Brazilian cerrado savanna covers nearly 2 million km2 and has a high incidence on foliage of various liquid food sources such as extrafloral nectar and insect exudates. These liquid rewards generate intense ant activity on cerrado foliage, making ant plant herbivore interactions especially prevalent in this biome. We present data on the distribution and abundance of extrafloral nectaries in the woody flora of cerrado communities and in the flora of other habitats worldwide, and stress the relevance of liquid food sources (including hemipteran honeydew) for the ant fauna. Consumption by ants of plant and insect exudates significantly affects the activity of the associated herbivores of cerrado plant species, with varying impacts on the reproductive output of the plants. Experiments with an ant plant butterfly system unequivocally demonstrate that the behavior of both immature and adult lepidopterans is closely related to the use of a risky host plant, where intensive visitation by ants can have a severe impact on caterpillar survival. We discuss recent evidence suggesting that the occurrence of liquid rewards on leaves plays a key role in mediating the foraging ecology of foliage-dwelling ants, and that facultative ant plant mutualisms are important in structuring the community of canopy arthropods. Ant-mediated effects on cerrado herbivore communities can be revealed by experiments performed on wide spatial scales, including many environmental factors such as soil fertility and vegetation structure. We also present some research questions that could be rewarding to investigate in this major neotropical savanna.

  17. Improvement and Implementation of Best-worst Ant Colony Algorithm

    Directory of Open Access Journals (Sweden)

    Xianmin Wei

    2013-05-01

    Full Text Available In this study, we introduced the ant colony algorithm of best-worst ant system based on the pheromone update. By update improvements of local pheromone and global pheromone, as well as the optimal solution enhancement to a greater extent and the weakening of the worst solution, the algorithm further increased the difference of pheromone amount between the edge of the optimal path and the edge of the worst path and allowed the ant colony search behavior more focused near the optimal solution. Finally, through simulation experiments to prove that the algorithm can get the optimal solution and the convergence rate is faster than the average ant colony algorithm.

  18. What is the effect of soil use on ant communities?

    Science.gov (United States)

    Schmidt, Fernando A; Diehl, Elena

    2008-01-01

    Studies on ant communities in agroecosystems have contributed to the knowledge of the effect of agricultural activities on biological communities. The aim of this study is to explain the effect of soil use on ant communities. We tested the hypothesis that there was a decrease in ant species richness and a change in the species composition at habitats with more intense soil use. We collected ants using sardine baits, subterranean traps and direct sampling at four habitats with different soil use (secundary forest, Acacia forestry, initial stage of succession and mixed crops). The ant species richness did not decrease with intensity of soil use. In successional habitat the species numbers collected using sardine baits and subterranean traps were significantly different. Species composition of communities had a pronounced variation, with the epigaeic and hypogaeic ant faunas of the habitat with high intense soil use (mixed crops) had low similarity with ant communities of the three other habitats. The predator species were restricted to habitats with low intensity of soil use. Then, species composition could better reflect the functional changes on ant communities than species richness. Our data can help to choose the component of ant community that better reflect the response of biodiversity to agricultural impacts.

  19. Looking and homing: how displaced ants decide where to go.

    Science.gov (United States)

    Zeil, Jochen; Narendra, Ajay; Stürzl, Wolfgang

    2014-01-01

    We caught solitary foragers of the Australian Jack Jumper ant, Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked their subsequent paths with a differential GPS. We find that upon surfacing from their transport vials onto a release platform, most ants move into the home direction after looking around briefly. The ants use a systematic scanning procedure, consisting of saccadic head and body rotations that sweep gaze across the scene with an average angular velocity of 90° s(-1) and intermittent changes in turning direction. By mapping the ants' gaze directions onto the local panorama, we find that neither the ants' gaze nor their decisions to change turning direction are clearly associated with salient or significant features in the scene. Instead, the ants look most frequently in the home direction and start walking fast when doing so. Displaced ants can thus identify home direction with little translation, but exclusively through rotational scanning. We discuss the navigational information content of the ants' habitat and how the insects' behaviour informs us about how they may acquire and retrieve that information.

  20. Five new records of ants (Hymenoptera: Formicidae) for Nebraska

    Science.gov (United States)

    Nemec, Kristine T.; Trager, James C.; Manley, Elizabeth; Allen, Craig R.

    2012-01-01

    Ants are ubiquitous and influential organisms in terrestrial ecosystems. About 1,000 ant species occur in North America, where they are found in nearly every habitat (Fisher and Cover 2007). Ants are critical to ecological processes and structure. Ants affect soils via tunneling activity (Baxter and Hole 1967), disperse plant seeds (Lengyel et al. 2009), prey upon a variety of insects and other invertebrates (Way and Khoo 1992, Folgarait 1998), are often effective primary consumers through their prodigious consumption of floral and especially extrafloral nectar, and honeydew (Tobin 1994), and serve as prey for invertebrates (Gotelli 1996, Gastreich 1999) and vertebrates (Reiss 2001).

  1. Variation of ant community structure on Ficus benguetensis

    Directory of Open Access Journals (Sweden)

    Shang-Yang Lin

    2016-03-01

    Full Text Available Although ants are commonly found on Ficus trees, information remains lacking on the pattern and diversity of the ant community visiting these trees. We hypothesize that dynamic changes in the availability and types of food can affect the composition as well as abundance of ant communities occurring on fig trees. To investigate the impact of resource availability, diversity, and variability on the ant community structure, we surveyed and recorded the fig phenology and ant abundance on 17 trees (11 male and six female trees of Ficus benguetensis in New Taipei City in northern Taiwan from 2011 to 2013. A total of 13 ant species were found on these fig trees, with 6 species more abundant than the others. The composition and relative abundance of the ant species occurring on F. benguetensis trees showed significant variations associated with tree sex, fig abundance, fig developmental phase, as well as temperature. A degree of dietary niche partitioning was also observed. We suggest that sexual differentiation in fig phenology plays a major role in controlling the availability and variance in food resources for ants, thereby shaping the complex ant communities foraging on F. benguetensis.

  2. Insecticide transfer efficiency and lethal load in Argentine ants

    Energy Technology Data Exchange (ETDEWEB)

    Hooper-Bui, L.M. [Department of Environmental Science, Louisiana State University, Baton Rouge, LA 70803 (United States); Department of Entomology, University of California, Riverside, CA 92521 (United States); Kwok, E.S.C. [Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521 (United States); Buchholz, B.A., E-mail: buchholz2@llnl.gov [Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Rust, M.K. [Department of Entomology, University of California, Riverside, CA 92521 (United States); Eastmond, D.A. [Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521 (United States); Vogel, J.S. [Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)

    2015-10-15

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of {sup 14}C-sucrose, {sup 14}C-hydramethylnon, and {sup 14}C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  3. 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...

  4. Evolution and ecology of directed aerial descent in arboreal ants.

    Science.gov (United States)

    Yanoviak, Stephen P; Munk, Yonatan; Dudley, Robert

    2011-12-01

    Directed aerial descent (DAD) is used by a variety of arboreal animals to escape predators, to remain in the canopy, and to access resources. Here, we build upon the discovery of DAD in ants of tropical canopies by summarizing its known phylogenetic distribution among ant genera, and within both the subfamily Pseudomyrmecinae and the genus Cephalotes. DAD has multiple evolutionary origins in ants, occurring independently in numerous genera in the subfamilies Myrmicinae, Formicinae, and Pseudomyrmecinae. Ablation experiments and video recordings of ants in a vertical wind tunnel showed that DAD in Cephalotes atratus is achieved via postural changes, specifically orientation of the legs and gaster. The occurrence of DAD in Formicinae indicates that the presence of a postpetiole is not essential for the behavior. Evidence to date indicates that gliding behavior is accomplished by visual targeting mediated by the compound eyes, and is restricted to diurnally active ants that nest in trees. Occlusion of ocelli in Pseudomyrmex gracilis workers had no effect on their success or performance in gliding. Experimental assessment of the fate of ants that fall to the understory showed that ants landing in water are 15 times more likely to suffer lethal attacks than are ants landing in leaf litter. Variation in both the aerodynamic mechanisms and selective advantages of DAD merits further study given the broad taxonomic diversity of arboreal ants that engage in this intriguing form of flight.

  5. Signals can trump rewards in attracting seed-dispersing ants.

    Science.gov (United States)

    Turner, Kyle M; Frederickson, Megan E

    2013-01-01

    Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes) of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds.

  6. Insecticide transfer efficiency and lethal load in Argentine ants

    Science.gov (United States)

    Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.

    2015-10-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  7. Signals can trump rewards in attracting seed-dispersing ants.

    Directory of Open Access Journals (Sweden)

    Kyle M Turner

    Full Text Available Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds.

  8. [Ants: a chemical library of anticancer molecules].

    Science.gov (United States)

    Vétillard, Angélique; Bouzid, Wafa

    2016-01-01

    Animal venoms are complex mixtures containing simple organic molecules, proteins, peptides, and other bioactive elements with extraordinary biological properties associated with their ability to act on a number of molecular receptors in the process of incapacitating their target organisms. In such a context, arthropod venoms are invaluable sources of bioactive substances, with therapeutic interest but the limited availability of some venom such as those from ants, has restricted the potential that these biomolecules could represent. We investigated for the first time transcriptomic expression from the ant species Tetramorium bicarinatum. Four hundred randomly selected clones from cDNA libraries were sequenced and a total of 374 expressed sequence tags (ESTs) were generated. Based on the results of BLAST searches, these sequences were clustered and assembled into 269 contigs. About 72% (269) of these matched BLASTx hits with an interesting diversity and unusual abundance of cellular transcripts (48%) related to gene and protein expression reflecting the specialization of this tissue. In addition, transcripts encoding transposases were relatively highly expressed (14%). It may be that transposable elements are present and that their presence accounts for some of the variation in venom toxins. About twenty per cent of the ESTs were categorized as putative toxins, the major part represented by allergens (48% of the total venom toxins) such as pilosulin 5, sol i 3 and Myp p I and II. Several contigs encoding enzymes, including zinc-metalloproteases (17%) that are likely involved in the processing and activation of venom proteins/peptides, were also identified from the library. In addition, a number of sequences (8%) had no significant similarity to any known sequence which indicates a potential source of for the discovery of new toxins. In order to provide a global insight on the transcripts expressed in the venom gland of the Brazilian ant species Tetramorium

  9. The evolution of invasiveness in garden ants.

    Directory of Open Access Journals (Sweden)

    Sylvia Cremer

    Full Text Available It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects.

  10. The evolution of invasiveness in garden ants.

    Science.gov (United States)

    Cremer, Sylvia; Ugelvig, Line V; Drijfhout, Falko P; Schlick-Steiner, Birgit C; Steiner, Florian M; Seifert, Bernhard; Hughes, David P; Schulz, Andreas; Petersen, Klaus S; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R; Nash, David R; Pedersen, Jes S; Boomsma, Jacobus J

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects.

  11. The acacia ants revisited: convergent evolution and biogeographic context in an iconic ant/plant mutualism.

    Science.gov (United States)

    Ward, Philip S; Branstetter, Michael G

    2017-03-15

    Phylogenetic and biogeographic analyses can enhance our understanding of multispecies interactions by placing the origin and evolution of such interactions in a temporal and geographical context. We use a phylogenomic approach-ultraconserved element sequence capture-to investigate the evolutionary history of an iconic multispecies mutualism: Neotropical acacia ants (Pseudomyrmex ferrugineus group) and their associated Vachellia hostplants. In this system, the ants receive shelter and food from the host plant, and they aggressively defend the plant against herbivores and competing plants. We confirm the existence of two separate lineages of obligate acacia ants that convergently occupied Vachellia and evolved plant-protecting behaviour, from timid ancestors inhabiting dead twigs in rainforest. The more diverse of the two clades is inferred to have arisen in the Late Miocene in northern Mesoamerica, and subsequently expanded its range throughout much of Central America. The other lineage is estimated to have originated in southern Mesoamerica about 3 Myr later, apparently piggy-backing on the pre-existing mutualism. Initiation of the Pseudomyrmex/Vachellia interaction involved a shift in the ants from closed to open habitats, into an environment with more intense plant herbivory. Comparative studies of the two lineages of mutualists should provide insight into the essential features binding this mutualism. © 2017 The Author(s).

  12. Ant Systems for a Dynamic TSP - Ants Caught in a Traffic Jam

    NARCIS (Netherlands)

    Eyckelhof, C.J.; Dorigo, M.; Caro Di, G.; Snoek, M.; Sampels, M.

    2002-01-01

    In this paper we present a new Ants System approach to a dynamic Travelling Salesman Problem. Here the travel times between the cities are subject to change. To handle this dynamism several ways of adapting the pheromone matrix both locally and globally are considered. We show that the strategy of

  13. Ants Laaneots : palgaarmeele üleminek pole praegu aktuaalne / Ants Laaneots ; interv. Peeter Kuimet

    Index Scriptorium Estoniae

    Laaneots, Ants, 1948-

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 6. dets. lk. 2. Kaitseväe uus juhataja kindralmajor Ants Laaneots vastab küsimustele kaitseväe ja ajateenistuse probleemide kohta. Lisa: Eesti kaitseväe juhatajad 1993-2006. Vt. samas: Laaneotsalt oodatakse sisetülide lahendamist

  14. Ants Laaneots : Peame venelaste provokatsiooniks valmis olema / Ants Laaneots ; interv. Urmo Soonvald

    Index Scriptorium Estoniae

    Laaneots, Ants, 1948-

    2002-01-01

    Ilmunud ka: Den za Dnjom 13. september lk. 9. Kindralmajor Ants Laaneots vastab küsimustele, kui reaalne on tulevikus Eesti pinnal sõja puhkemise oht, 11. septembri sündmuste kohta USA-s, Eesti NATO liikmeks kutsumise, provokatsioonide vastu valmisoleku, võõrriigi oletatava Eestisse sissetungi kohta

  15. The evolution of invasiveness in garden ants

    DEFF Research Database (Denmark)

    Cremer, Sylvia; Ugelvig, Line Vej; Drijfhout, Falko P

    2008-01-01

    rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus...... relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic...

  16. Salud mental ante las crisis y desastres

    OpenAIRE

    2016-01-01

    La Salud Mental es un componente nuclear del bienestar personal y colectivo, es un concepto que aunque parcial de la salud general constituye el único camino probablemente para acercarse a la felicidad y la paz que todos los seres humanos (salvo excepciones) buscamos. Y las crisis y los desastres son eventos más allá de lo esperable que sobrepasa las defensas del ser humano y ante el que hay que enfrentarse con rapidez, eficacia, orden, multiprofesionalmente pero sobre todo con calma int...

  17. Esimene keelepeegel / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2016-01-01

    Ferdinand Johann Wiedemanni 1869. a. ilmunud "Eesti-saksa sõnaraamatut" võib pidada eesti keele institutsionaliseerimiseks, seletavate ja õigekeelsussõnaraamatute eelkäijaks, keelevaramu müürikiviks ja keelepeegliks

  18. Maarahvast eestlasteks / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2016-01-01

    Johann Voldemar Jannseni luulevormis pöördumises 5. juunil 1857. a. ilmumist alustanud nädalalehes "Pärnu Postimees", milles ta määratles lugejaskonna - eesti rahvas. "Eestimaa", "eesti" ja "eesti rahvas" kasutusesest kirjasõnas

  19. Raamatututvustus / Rein Põder

    Index Scriptorium Estoniae

    Põder, Rein, 1943-

    1995-01-01

    Rousseau, Jean-Jacques. Üksildase uitaja mõtisklused; Hill, Susan. Proua de Winter; Kõrvemaast põhjarannani : Kuusalu kihelkonna kirjanduslik-kodulooline antoloogia / Koost. Helmut Elstrok; Tead.toim. Oskar Kuningas

  20. Eerosest valgustatud / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2002-01-01

    Arvustus: Saarsen, Karin. Lõvi ja orhidee : [luuletused]. Tallinn : Eesti Raamat, 2002 ; Under, Marie. Under armastusest : [luuletused ja katkendid kirjadest] / valik ja järelsõna: Sirje Olesk. Tallinn : Tänapäev, 2002

  1. Plaadid / Rein Vader

    Index Scriptorium Estoniae

    Vader, Rein

    2006-01-01

    Uutest heliplaatidest Deftones "Saturday Night Wrist", Robb Scott "Afro Adyssey", Zucchero "Fly", Agoria "The Green Armchair", "Back To The Bus ئ Babyshambes", Fratellis "Costello Music", Rod Stewart "Still The Same..."

  2. Kolmekordne kupar / Rein Saluri

    Index Scriptorium Estoniae

    Saluri, Rein

    1998-01-01

    Arvustus: Kristof, Agota. Kaustik; Katsumus; Kolmas vale / prantsuse k. tlk. Urmas Rattus. Tallinn : Varrak, 1997. (Moodne klassika); Oz, Amos. Ära ütle, et öö / heebrea k. tlk. Kalle Kasemaa. Tallinn : Kupar, 1998; Weldon, Fay. Kuu Minneapolise kohal / inglise k. tlk. Faina Laksberg. Tallinn : Kupar, 1997

  3. Kikivarvul hullumajja? / Rein Taagepera

    Index Scriptorium Estoniae

    Taagepera, Rein, 1933-

    2009-01-01

    Praeguse teabeühiskonna üha kiirema kohanemise ja ümber õppimise vajadusest. Autor leiab, et kiirenev tempo takistab süvenemist. Pealiskaudsed otsused tehakse ära endisest kiiremini, sest reageerimiseks saadaval olev aeg lüheneb

  4. Kriitika kriis / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis auhinna Aasta film 2002 mängufilmile "Agent Sinikael" : režissöör Marko Raat. Autor jagab auhinna rahastajate Ene ja Tõnis Kase rahuloematust seoses filmi "Nimed marmortahvlil" väljajätmisega isegi nominentide hulgast

  5. Raamatututvustus / Rein Põder

    Index Scriptorium Estoniae

    Põder, Rein, 1943-

    1995-01-01

    Rousseau, Jean-Jacques. Üksildase uitaja mõtisklused; Hill, Susan. Proua de Winter; Kõrvemaast põhjarannani : Kuusalu kihelkonna kirjanduslik-kodulooline antoloogia / Koost. Helmut Elstrok; Tead.toim. Oskar Kuningas

  6. Estlinki merekaabel / Rein Aro

    Index Scriptorium Estoniae

    Aro, Rein, 1942-

    2006-01-01

    Järg. nr. 6 lk. 20-21. Eesti ja Soome vahelise elektrilise ühenduse loomisest. Kaabelliini haldab ühisettevõte Nordic Energy Link. Ehitaja leidmiseks kuulutatud hanke võitis Šveitsi-Rootsi kontsern ABB

  7. Arvustused / Rein Vader

    Index Scriptorium Estoniae

    Vader, Rein

    2000-01-01

    Uute plaatide AC/DC "Stiff Upper Lip", Alex Attias "Hi-Fi Jazz", Asian Dub Foundation "Community Music", Beastie Boys "Anthology: The Sounds Of Sciense", Blind "Jolly Good", Charlotte Church "Charlotte Church", Crazy Town "The Gift of Game", Cure "Bloodflowers", Tracy Chapman "Telling Stories", "Bringing Out The Dead" arvustused

  8. Arvustused / Rein Vader

    Index Scriptorium Estoniae

    Vader, Rein

    2000-01-01

    Uute plaatide AC/DC "Stiff Upper Lip", Alex Attias "Hi-Fi Jazz", Asian Dub Foundation "Community Music", Beastie Boys "Anthology: The Sounds Of Sciense", Blind "Jolly Good", Charlotte Church "Charlotte Church", Crazy Town "The Gift of Game", Cure "Bloodflowers", Tracy Chapman "Telling Stories", "Bringing Out The Dead" arvustused

  9. Reining in Coercive Power

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Law furthers administration system On June 30,the Standing Committee of the 11th National People’s Congress(NPC),China’s top legislature,adopted the Law on Administrative Coercion at its 21st meeting."The law stipulates specific procedures

  10. Eerosest valgustatud / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2002-01-01

    Arvustus: Saarsen, Karin. Lõvi ja orhidee : [luuletused]. Tallinn : Eesti Raamat, 2002 ; Under, Marie. Under armastusest : [luuletused ja katkendid kirjadest] / valik ja järelsõna: Sirje Olesk. Tallinn : Tänapäev, 2002

  11. Reformer Takes French Reins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The painful reforms chosen by French voters to rejuvenate their sluggish economy have smoothed the way for Nicolas Sarkozy to take up France’s top political job.The 52-year-old leader of the ruling right-wing Union

  12. Eestlasi kindralimundris / Rein Helme

    Index Scriptorium Estoniae

    Helme, Rein, 1954-2003

    1991-01-01

    Järg nr. 3,7,9 lk. 21-22,12-14,16-17. Johan Laidoner,Ernst Põdder,Jaan Soots, Nikolai Reek, Paul Lill, Andres Larka, Aleksander Tõnisson, Jaan Soots, Vabadussõjas karastunud: Otto Heinze, Gustav Jonson, Herbert Brede, Hugo Kauler, Jaan Kruus, Eesti kaitseväe majandusjuhid Rudolf Reimann, Tõnis Rotberg, Aleksander Silberg

  13. Reining the River

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Concerned about the effects of increasing water scarcity on economic development, China hopes a new law will save the Yellow River The first day of August marked what could be a new page in the history of China's long-suffering "mother river." That day, a regulation took effect that for the first time in histo-

  14. Halb nullvariant / Rein Taagepera

    Index Scriptorium Estoniae

    Taagepera, Rein, 1933-

    2002-01-01

    Ilmunud ka: Infopress 9. august nr. 32 lk. 34. On aeg uuesti läbi mõelda, kuidas süvendada eesti meelt ja eesti keelt 220 000 mittekodaniku hulgas. Kodakondsuseksami asemel võiks kaaluda 150-tunnise harjutuse läbimist, pakub autor. Autor: Res Publica

  15. Kriitika kriis / Rein Veidemann

    Index Scriptorium Estoniae

    Veidemann, Rein, 1946-

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis auhinna Aasta film 2002 mängufilmile "Agent Sinikael" : režissöör Marko Raat. Autor jagab auhinna rahastajate Ene ja Tõnis Kase rahuloematust seoses filmi "Nimed marmortahvlil" väljajätmisega isegi nominentide hulgast

  16. Distance and Involvement : Visualising History in Patrice Chéreau's La Reine Margot (1994 and in Éric Rohmer's L'Anglaise et le duc (2001

    Directory of Open Access Journals (Sweden)

    Margriet Hoogvliet

    2012-10-01

    Full Text Available This article analyses strategies of visualisation of the past in two French films d'histoire: La Reine Margot (1994 by directed by Patrice Chéreau and L'Anglaise et le duc (2001 by Éric Rohmer. Both films have modern political and societal implications: Chéreau's film contains several clear hints towards a reading of the “greatest massacre” of France's past as a critique of the modern era, while Rohmer rather wanted to make his audience aware of the ambiguities of the founding period of the French Republic. However, the two film directors have made use of completely different strategies for visualising the past and in order to involve their audiences: Chéreau by making a conscious use of visual anachronisms and Rohmer by a scrupulous reconstruction of a painterly historical vision.

  17. The effect of diet and opponent size on aggressive interactions involving caribbean crazy ants (Nylanderia fulva).

    Science.gov (United States)

    Horn, Katherine C; Eubanks, Micky D; Siemann, Evan

    2013-01-01

    Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants.

  18. The importance of ants in cave ecology, with new records and behavioral observations of ants in Arizona caves

    Directory of Open Access Journals (Sweden)

    Robert B. Pape

    2016-09-01

    Full Text Available The importance of ants as elements in cave ecology has been mostly unrecognized. A global list of ant species recorded from caves, compiled from a review of existing literature, is presented. This paper also reviews what is currently known about ants occurring in Arizona (USA caves. The diversity and distribution represented in these records suggests ants are relatively common cave visitors (trogloxenes. A general utilization of caves by ants within both temperate and tropical latitudes may be inferred from this combined evidence. Observations of ant behavior in Arizona caves demonstrate a low level and sporadic, but persistent, use of these habitats and their contained resources by individual ant colonies. Documentation of Neivamyrmex sp. preying on cave-inhabiting arthropods is reported here for the first time. Observations of hypogeic army ants in caves suggests they may not penetrate to great vertical depth in search of prey, but can be persistent occupants in relatively shallow, horizontal sections of caves where they may prey on endemic cave animals. First cave records for ten ant species are reported from Arizona caves. These include two species of Neivamyrmex (N. nigrescens Cresson and Neivamyrmex sp.; Formicidae: Dorylinae, four myrmicines (Pheidole portalensis Wilson, Pheidole cf. porcula Wheeler, Solenopsis aurea Wheeler and Stenamma sp. Westwood, one dolichoderine (Forelius keiferi Wheeler and three formicines (Lasius arizonicus Wheeler, L. sitiens Wilson, and Camponotus sp. Mayr.

  19. Nectar Theft and Floral Ant-Repellence: A Link between Nectar Volume and Ant-Repellent Traits?

    Science.gov (United States)

    Ballantyne, Gavin; Willmer, Pat

    2012-01-01

    As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions. PMID:22952793

  20. Eggs of Mallada desjardinsi (Neuroptera: Chrysopidae) are protected by ants: the role of egg stalks in ant-tended aphid colonies.

    Science.gov (United States)

    Hayashi, Masayuki; Nomura, Masashi

    2014-08-01

    In ant-aphid mutualisms, ants usually attack and exclude enemies of aphids. However, larvae of the green lacewing Mallada desjardinsi (Navas) prey on ant-tended aphids without being excluded by ants; these larvae protect themselves from ants by carrying aphid carcasses on their backs. Eggs of M. desjardinsi laid at the tips of stalks have also been observed in ant-tended aphid colonies in the field. Here, we examined whether the egg stalks of M. desjardinsi protect the eggs from ants and predators. When exposed to ants, almost all eggs with intact stalks were untouched, whereas 50-80% of eggs in which stalks had been severed at their bases were destroyed by ants. In contrast, most eggs were preyed upon by larvae of the lacewing Chrysoperla nipponensis (Okamoto), an intraguild predator of M. desjardinsi, regardless of whether their stalks had been severed. These findings suggest that egg stalks provide protection from ants but not from C. nipponensis larvae. To test whether M. desjardinsi eggs are protected from predators by aphid-tending ants, we introduced C. nipponensis larvae onto plants colonized by ant-tended aphids. A significantly greater number of eggs survived in the presence of ants because aphid-tending ants excluded larvae of C. nipponensis. This finding indicates that M. desjardinsi eggs are indirectly protected from predators by ants in ant-tended aphid colonies.

  1. Fecundity and longevity of Argentine ant (Hymenoptera: Formicidae) queens in response to irradiation

    Science.gov (United States)

    Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. As little is known about irradiation effects on ants, radiotolerance of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae...

  2. Inga Kuusik vallutas tippe Kõrgõzstanis / Heli Talinurm

    Index Scriptorium Estoniae

    Talinurm, Heli

    2007-01-01

    Saku Õlletehase uus finantsdirektor tööst tubakatootja Imperial Tobacco Grupi Kesk-Aasia regiooni finantsdirektorina Kõrgõzstanis, kohalikest inimestest ja töökultuurist. Lisa: Fakte Kõrgõzstani kohta

  3. Mis on õiglane kaubandus? / Riina Kuusik ; interv. Inge Pitsner

    Index Scriptorium Estoniae

    Kuusik, Riina

    2006-01-01

    ETV saate "Tasakaal" tegijad külastasid Nicaraguat ja Costa Ricat, et vaadata, kuidas elavad ja töötavad "õiglase kaubanduse" süsteemi kuuluvad talunikud, õiglase kaubanduse (fairtrade) mõistest

  4. Eesti Arhitektide Ühingu asutajate... / Edgar Johan Kuusik

    Index Scriptorium Estoniae

    Kuusik, Edgar Johan

    1999-01-01

    Eesti Arhitektide Ühingu eesmärgist ja tegevusest. EAÜ asutajate esimene koosolek peeti 8. X 1921. a., ühingu põhikiri kinnitati 23. III 1922. a. Arhitektide kutsealasest organiseerimisest. 1935. a. kinnitati Insenerikoja põhikiri ja arhitektid koondati Insenerikoja arhitektuurisektsiooni. Märkus: dateerimata käsikiri Eesti Arhitektuurimuuseumis

  5. Mis on õiglane kaubandus? / Riina Kuusik ; interv. Inge Pitsner

    Index Scriptorium Estoniae

    Kuusik, Riina

    2006-01-01

    ETV saate "Tasakaal" tegijad külastasid Nicaraguat ja Costa Ricat, et vaadata, kuidas elavad ja töötavad "õiglase kaubanduse" süsteemi kuuluvad talunikud, õiglase kaubanduse (fairtrade) mõistest

  6. Inga Kuusik vallutas tippe Kõrgõzstanis / Heli Talinurm

    Index Scriptorium Estoniae

    Talinurm, Heli

    2007-01-01

    Saku Õlletehase uus finantsdirektor tööst tubakatootja Imperial Tobacco Grupi Kesk-Aasia regiooni finantsdirektorina Kõrgõzstanis, kohalikest inimestest ja töökultuurist. Lisa: Fakte Kõrgõzstani kohta

  7. Ant Foraging Behavior for Job Shop Problem

    Directory of Open Access Journals (Sweden)

    Mahad Diyana Abdul

    2016-01-01

    Full Text Available Ant Colony Optimization (ACO is a new algorithm approach, inspired by the foraging behavior of real ants. It has frequently been applied to many optimization problems and one such problem is in solving the job shop problem (JSP. The JSP is a finite set of jobs processed on a finite set of machine where once a job initiates processing on a given machine, it must complete processing and uninterrupted. In solving the Job Shop Scheduling problem, the process is measure by the amount of time required in completing a job known as a makespan and minimizing the makespan is the main objective of this study. In this paper, we developed an ACO algorithm to minimize the makespan. A real set of problems from a metal company in Johor bahru, producing 20 parts with jobs involving the process of clinching, tapping and power press respectively. The result from this study shows that the proposed ACO heuristics managed to produce a god result in a short time.

  8. Polydomy enhances foraging performance in ant colonies.

    Science.gov (United States)

    Stroeymeyt, N; Joye, P; Keller, L

    2017-04-26

    Collective foraging confers benefits in terms of reduced predation risk and access to social information, but it heightens local competition when resources are limited. In social insects, resource limitation has been suggested as a possible cause for the typical decrease in per capita productivity observed with increasing colony size, a phenomenon known as Michener's paradox. Polydomy (distribution of a colony's brood and workers across multiple nests) is believed to help circumvent this paradox through its positive effect on foraging efficiency, but there is still little supporting evidence for this hypothesis. Here, we show experimentally that polydomy enhances the foraging performance of food-deprived Temnothorax nylanderi ant colonies via several mechanisms. First, polydomy influences task allocation within colonies, resulting in faster retrieval of protein resources. Second, communication between sister nests reduces search times for far away resources. Third, colonies move queens, brood and workers across available nest sites in response to spatial heterogeneities in protein and carbohydrate resources. This suggests that polydomy represents a flexible mechanism for space occupancy, helping ant colonies adjust to the environment. © 2017 The Author(s).

  9. Odorous house ants (Tapinoma sessile) as back-seat drivers of localized ant decline in urban habitats.

    Science.gov (United States)

    Salyer, Adam; Bennett, Gary W; Buczkowski, Grzegorz A

    2014-01-01

    Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile), within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers) threats as instigators or secondary (passengers) threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74%) and abundance (81%). Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban 'invasion'. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a "back

  10. Host ant independent oviposition in the parasitic butterfly Maculinea alcon

    DEFF Research Database (Denmark)

    Fürst, Matthias A; Nash, David Richard

    2010-01-01

    Parasitic Maculinea alcon butterflies can only develop in nests of a subset of available Myrmica ant species, so female butterflies have been hypothesized to preferentially lay eggs on plants close to colonies of the correct host ants. Previous correlational investigations of host...... is necessary for conservation of this endangered butterfly....

  11. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai;

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cul...

  12. Novel Phialophora species from leaf-cutting ants (tribe Attini)

    NARCIS (Netherlands)

    Attili-Angelis, D.; Duarte, A.P.M.; Pagnocca, F.C.; Nagamoto, N.S.; de Vries, M.; Stielow, J.B.; de Hoog, G.S.

    2014-01-01

    Ants in the tribe Attini (Hymenoptera, Formicidae) maintain a 50 million-year-old lifestyle of co-evolution with symbiotic basidiomycetous fungi which they cultivate as essential source of nutrition. However, other microorganisms have been reported from ant habitats indicating a higher diversity of

  13. Tracing the rise of ants - out of the ground.

    Directory of Open Access Journals (Sweden)

    Andrea Lucky

    Full Text Available The evolution of ants (Hymenoptera: Formicidae is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil. Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today.

  14. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  15. Sucking pump activity in feeding behaviour regulation in carpenter ants.

    Science.gov (United States)

    Falibene, Agustina; Gontijo, Alberto de Figueiredo; Josens, Roxana

    2009-06-01

    Modulation of liquid feeding-rate would allow insects to ingest more food in the same time when this was required. Ants can vary nectar intake rate by increasing sucking pump frequency according to colony requirements. We analysed electrical signals generated by sucking pump activity of ants during drinking solutions of different sucrose concentrations and under different carbohydrate-deprivation levels. Our aim was to define parameters that characterize the recordings and analyse their relationship with feeding behaviour. Signals showed that the initial and final frequencies of sucking pump activity, as well as the difference between them were higher in sugar-deprived ants. However, these parameters were not influenced by sucrose solution concentration, which affected the number of pump contractions and the volume per contraction. Unexpectedly, we found two different responses in feeding behaviour of starved and non-starved ants depending on concentration. Starved ants drank dilute solutions for the same length of time as non-starved ants but ingested higher volumes. While drinking the concentrated solutions, starved ants drank the same volume, but did so in a shorter time than the non-starved ones. Despite these differences, for each analysed concentration the total number of pump contractions remained constant independently of sugar-deprivation level. These results are discussed in the frame of feeding regulation and decision making in ant foraging behaviour.

  16. Chaos-order transition in foraging behavior of ants.

    Science.gov (United States)

    Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

    2014-06-10

    The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants' physical abilities, and ants' knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal.

  17. Tracing the rise of ants - out of the ground.

    Science.gov (United States)

    Lucky, Andrea; Trautwein, Michelle D; Guénard, Benoit S; Weiser, Michael D; Dunn, Robert R

    2013-01-01

    The evolution of ants (Hymenoptera: Formicidae) is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil). Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today.

  18. Patterns of male parentage in the fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Boomsma, JJ

    2003-01-01

    Ant queens from eight species, covering three genera of lower and two genera of higher attine ants, have exclusively or predominantly single mating. The ensuing full-sib colonies thus have a strong potential reproductive conflict between the queen and the workers over male production...

  19. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai;

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  20. Energy Efficient Routing in Wireless Sensor Networks based on Ant ...

    African Journals Online (AJOL)

    PROF. O. E. OSUAGWU

    2013-09-01

    Sep 1, 2013 ... energy efficient manner. Ant Colony Optimization, a swarm intelligence based optimization ... to WSNs, many routing schemes using end-to-end devices ..... This task is performed by sending ant k back to its source node from ...

  1. Diversity of peptide toxins from stinging ant venoms.

    Science.gov (United States)

    Aili, Samira R; Touchard, Axel; Escoubas, Pierre; Padula, Matthew P; Orivel, Jérôme; Dejean, Alain; Nicholson, Graham M

    2014-12-15

    Ants (Hymenoptera: Formicidae) represent a taxonomically diverse group of arthropods comprising nearly 13,000 extant species. Sixteen ant subfamilies have individuals that possess a stinger and use their venom for purposes such as a defence against predators, competitors and microbial pathogens, for predation, as well as for social communication. They exhibit a range of activities including antimicrobial, haemolytic, cytolytic, paralytic, insecticidal and pain-producing pharmacologies. While ant venoms are known to be rich in alkaloids and hydrocarbons, ant venoms rich in peptides are becoming more common, yet remain understudied. Recent advances in mass spectrometry techniques have begun to reveal the true complexity of ant venom peptide composition. In the few venoms explored thus far, most peptide toxins appear to occur as small polycationic linear toxins, with antibacterial properties and insecticidal activity. Unlike other venomous animals, a number of ant venoms also contain a range of homodimeric and heterodimeric peptides with one or two interchain disulfide bonds possessing pore-forming, allergenic and paralytic actions. However, ant venoms seem to have only a small number of monomeric disulfide-linked peptides. The present review details the structure and pharmacology of known ant venom peptide toxins and their potential as a source of novel bioinsecticides and therapeutic agents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The hyper-cube framework for ant colony optimization.

    Science.gov (United States)

    Blum, Christian; Dorigo, Marco

    2004-04-01

    Ant colony optimization is a metaheuristic approach belonging to the class of model-based search algorithms. In this paper, we propose a new framework for implementing ant colony optimization algorithms called the hyper-cube framework for ant colony optimization. In contrast to the usual way of implementing ant colony optimization algorithms, this framework limits the pheromone values to the interval [0,1]. This is obtained by introducing changes in the pheromone value update rule. These changes can in general be applied to any pheromone value update rule used in ant colony optimization. We discuss the benefits coming with this new framework. The benefits are twofold. On the theoretical side, the new framework allows us to prove that in Ant System, the ancestor of all ant colony optimization algorithms, the average quality of the solutions produced increases in expectation over time when applied to unconstrained problems. On the practical side, the new framework automatically handles the scaling of the objective function values. We experimentally show that this leads on average to a more robust behavior of ant colony optimization algorithms.

  3. Ant colony induced decision trees for intrusion detection

    CSIR Research Space (South Africa)

    Botes, FH

    2017-06-01

    Full Text Available within machine learning, specifically the Ant Tree Miner (ATM) classifier. The ATM classifier proposed by Otero, Freitas & Johnson (2012) builds decision trees using ant colony optimization instead of traditional C4.5 or CART techniques. Our experimental...

  4. Comparative studies of the secretome of fungus-growing ants

    DEFF Research Database (Denmark)

    Linde, Tore; Grell, Morten Nedergaard; Schiøtt, Morten

    2009-01-01

    Leafcutter ants of the species Acromyrmex echinatior live in symbiosis with the fungus Leucoagaricus gongylophorus. The ants harvest fragments of leaves and carry them to the nest where they place the material on the fungal colony. The fungus secretes a wide array of proteins to degrade the leave...

  5. Patterns of male parentage in the fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Boomsma, JJ

    2003-01-01

    Ant queens from eight species, covering three genera of lower and two genera of higher attine ants, have exclusively or predominantly single mating. The ensuing full-sib colonies thus have a strong potential reproductive conflict between the queen and the workers over male production...

  6. AntNet: Distributed Stigmergetic Control for Communications Networks

    CERN Document Server

    Di Caro, G

    2011-01-01

    This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurrently explore the network and exchange collected information. The communication among the agents is indirect and asynchronous, mediated by the network itself. This form of communication is typical of social insects and is called stigmergy. We compare our algorithm with six state-of-the-art routing algorithms coming from the telecommunications and machine learning fields. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and artificial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal traffic distributions. Results are very encouraging. AntNet showed superior performance under all the experimental condit...

  7. SECURING MOBILE ANT AGENT USING CHINESE REMAINDER THEOREM

    Directory of Open Access Journals (Sweden)

    Srinath Doss

    2013-01-01

    Full Text Available Recent days, research in wireless network becomes major area for the past few decades. In wireless routing many routing methods such as table driven, source driven; many characteristics such as reactive routing, proactive routing; many routing algorithms such as dijikstra’s shortest path, distributed bell-man ford algorithm are proposed in the literature. For effective wireless routing, the recent ant colony optimization proves better result than the existing methodologies. The ant colony optimization is a swarm intelligence technique which widely used for combinatorial optimization problems such as travelling salesman, network routing, clustering. The ant colony optimization is a real time routing protocol which offers highly reliable and optimal routing for both single path and multi path routing. As the ant is a small tiny mobile agent, providing security is critical issue. In this study, a secured ant colony optimization using Chinese remainder theorem is proposed.

  8. A Novel Parser Design Algorithm Based on Artificial Ants

    CERN Document Server

    Maiti, Deepyaman; Konar, Amit; Ramadoss, Janarthanan

    2008-01-01

    This article presents a unique design for a parser using the Ant Colony Optimization algorithm. The paper implements the intuitive thought process of human mind through the activities of artificial ants. The scheme presented here uses a bottom-up approach and the parsing program can directly use ambiguous or redundant grammars. We allocate a node corresponding to each production rule present in the given grammar. Each node is connected to all other nodes (representing other production rules), thereby establishing a completely connected graph susceptible to the movement of artificial ants. Each ant tries to modify this sentential form by the production rule present in the node and upgrades its position until the sentential form reduces to the start symbol S. Successful ants deposit pheromone on the links that they have traversed through. Eventually, the optimum path is discovered by the links carrying maximum amount of pheromone concentration. The design is simple, versatile, robust and effective and obviates ...

  9. A stochastic model of ant trail following with two pheromones

    CERN Document Server

    Malíčková, Miriam; Boďová, Katarína

    2015-01-01

    Colonies of ants are systems of interacting living organisms in which interactions between individuals and their environment can produce a reliable performance of a complex tasks without the need for centralised control. Particularly remarkable is the process of formation of refined paths between the nest and food sources that is essential for successful foraging. We have designed a simple stochastic off-lattice model of ant foraging in the absence of direct communication. The motion of ants is governed by two components - a random change in direction of motion that improves ability to explore the environment (facilitating food discovery), and a non-random global indirect interaction component based on pheromone signalling. Using numerical simulations we have studied the model behaviour in different parameter regimes and tested the ability of our model ants to adapt to changes in the external environment. The simulated behaviour of ants in the model recapitulated the experimentally observed behaviours of real...

  10. Eavesdropping on cooperative communication within an ant-butterfly mutualism

    Science.gov (United States)

    Elgar, Mark A.; Nash, David R.; Pierce, Naomi E.

    2016-10-01

    Signalling is necessary for the maintenance of interspecific mutualisms but is vulnerable to exploitation by eavesdropping. While eavesdropping of intraspecific signals has been studied extensively, such exploitation of interspecific signals has not been widely documented. The juvenile stages of the Australian lycaenid butterfly, Jalmenus evagoras, form an obligate association with several species of attendant ants, including Iridomyrmex mayri. Ants protect the caterpillars and pupae, and in return are rewarded with nutritious secretions. Female and male adult butterflies use ants as signals for oviposition and mate searching, respectively. Our experiments reveal that two natural enemies of J. evagoras, araneid spiders and braconid parasitoid wasps, exploit ant signals as cues for increasing their foraging and oviposition success, respectively. Intriguingly, selection through eavesdropping is unlikely to modify the ant signal.

  11. Behind every great ant, there is a great gut

    DEFF Research Database (Denmark)

    Poulsen, Michael; Sapountzis, Panagiotis

    2012-01-01

    Ants are quite possibly the most successful insects on Earth, with an estimated 10 000 species worldwide, making up at least a third of the global insect biomass, and comprising several times the biomass of all land vertebrates combined. Ant species have diverse trophic habits, including herbivory...... on the potential contribution of the ants’ gut symbionts. This issue of Molecular Ecology contains a study by Anderson et al. (2012), who take a comparative approach to explore the link between trophic levels and ant microbiomes, specifically, to address three main questions: (i) Do closely related herbivorous...... conserved gut microbiomes, suggesting symbiont functions that directly relate to dietary preference of the ant host. These findings suggest an ecological role of gut symbionts in ants, for example, in metabolism and/or protection, and the comparative approach taken supports a model of co-evolution between...

  12. An ant colony algorithm on continuous searching space

    Science.gov (United States)

    Xie, Jing; Cai, Chao

    2015-12-01

    Ant colony algorithm is heuristic, bionic and parallel. Because of it is property of positive feedback, parallelism and simplicity to cooperate with other method, it is widely adopted in planning on discrete space. But it is still not good at planning on continuous space. After a basic introduction to the basic ant colony algorithm, we will propose an ant colony algorithm on continuous space. Our method makes use of the following three tricks. We search for the next nodes of the route according to fixed-step to guarantee the continuity of solution. When storing pheromone, it discretizes field of pheromone, clusters states and sums up the values of pheromone of these states. When updating pheromone, it makes good resolutions measured in relative score functions leave more pheromone, so that ant colony algorithm can find a sub-optimal solution in shorter time. The simulated experiment shows that our ant colony algorithm can find sub-optimal solution in relatively shorter time.

  13. Remote Sensing Image Feature Extracting Based Multiple Ant Colonies Cooperation

    Directory of Open Access Journals (Sweden)

    Zhang Zhi-long

    2014-02-01

    Full Text Available This paper presents a novel feature extraction method for remote sensing imagery based on the cooperation of multiple ant colonies. First, multiresolution expression of the input remote sensing imagery is created, and two different ant colonies are spread on different resolution images. The ant colony in the low-resolution image uses phase congruency as the inspiration information, whereas that in the high-resolution image uses gradient magnitude. The two ant colonies cooperate to detect features in the image by sharing the same pheromone matrix. Finally, the image features are extracted on the basis of the pheromone matrix threshold. Because a substantial amount of information in the input image is used as inspiration information of the ant colonies, the proposed method shows higher intelligence and acquires more complete and meaningful image features than those of other simple edge detectors.

  14. Chemical signals associated with life inhibit necrophoresis in Argentine ants

    Science.gov (United States)

    Choe, Dong-Hwan; Millar, Jocelyn G.; Rust, Michael K.

    2009-01-01

    One of the most conspicuous and stereotyped activities of social insects such as ants and honey bees is necrophoresis, the removal of dead colony members from the nest. Previous researchers suggested that decomposition products such as fatty acids trigger necrophoric behavior by ant workers. However, fatty acids elicit both foraging and necrophoric responses, depending on the current nest activities (e.g., feeding or nest maintenance). Furthermore, workers often carry even freshly killed workers (dead for Linepithema humile, undergoes rapid changes after death. When the workers are alive or freshly killed, relatively large amounts of 2 characteristic ant-produced compounds, dolichodial and iridomyrmecin, are present on the ants' cuticle. However, these compounds disappear from the cuticle within about 1 h after death. We demonstrate how this phenomenon supports an alternative mechanism of ant necrophoresis in which the precise recognition and rapid removal of dead nestmates are elicited by the disappearance of these chemical signals associated with life. PMID:19416815

  15. The rise of army ants and their relatives: diversification of specialized predatory doryline ants.

    Science.gov (United States)

    Brady, Seán G; Fisher, Brian L; Schultz, Ted R; Ward, Philip S

    2014-05-01

    Army ants are dominant invertebrate predators in tropical and subtropical terrestrial ecosystems. Their close relatives within the dorylomorph group of ants are also highly specialized predators, although much less is known about their biology. We analyzed molecular data generated from 11 nuclear genes to infer a phylogeny for the major dorylomorph lineages, and incorporated fossil evidence to infer divergence times under a relaxed molecular clock. Because our results indicate that one subfamily and several genera of dorylomorphs are non-monophyletic, we propose to subsume the six previous dorylomorph subfamilies into a single subfamily, Dorylinae. We find the monophyly of Dorylinae to be strongly supported and estimate the crown age of the group at 87 (74-101) million years. Our phylogenetic analyses provide only weak support for army ant monophyly and also call into question a previous hypothesis that army ants underwent a fundamental split into New World and Old World lineages. Outside the army ants, our phylogeny reveals for the first time many old, distinct lineages in the Dorylinae. The genus Cerapachys is shown to be non-monophyletic and comprised of multiple lineages scattered across the Dorylinae tree. We recover, with strong support, novel relationships among these Cerapachys-like clades and other doryline genera, but divergences in the deepest parts of the tree are not well resolved. We find the genus Sphinctomyrmex, characterized by distinctive abdominal constrictions, to consist of two separate lineages with convergent morphologies, one inhabiting the Old World and the other the New World tropics. While we obtain good resolution in many parts of the Dorylinae phylogeny, relationships deep in the tree remain unresolved, with major lineages joining each other in various ways depending upon the analytical method employed, but always with short internodes. This may be indicative of rapid radiation in the early history of the Dorylinae, but additional

  16. Assessing ant seed predation in threatened plants: a case study

    Science.gov (United States)

    Albert, María José; Escudero, Adrián; Iriondo, José María

    2005-11-01

    Erodium paularense is a threatened plant species that is subject to seed predation by the granivorous ant Messor capitatus. In this paper we assessed the intensity and pattern of ant seed predation and looked for possible adaptive strategies at the seed and plant levels to cope with this predation. Seed predation was estimated in 1997 and 1998 at the population level by comparing total seed production and ant consumption, assessed by counting seed hulls in refuse piles. According to this method, ant seed predation ranged between 18% and 28%. A more detailed and direct assessment conducted in 1997 raised this estimate to 43%. In this assessment spatial and temporal patterns of seed predation by ants were studied by mapping all nest entrances in the studied area and marking the mature fruits of 109 reproductive plants with a specific colour code throughout the seed dispersal period. Intact fruit coats were later recovered from the refuse piles, and their mother plants and time of dispersal were identified. Seeds dispersed at the end of the dispersal period had a greater probability of escaping from ant seed predation. Similarly, in plants with late dispersal a greater percentage of seeds escaped from ant predation. Optimum dispersal time coincided with the maximum activity of granivorous ants because, at this time, ants focused their harvest on other plant species of the community. It was also observed that within-individual seed dispersal asynchrony minimised seed predation. From a conservation perspective, results show that the granivorous ant-plant interaction cannot be assessed in isolation and that the intensity of its effects basically depends on the seed dispersal pattern of the other members of the plant community. Furthermore, this threat must be assessed by considering the overall situation of the target population. Thus, in E. paularense, the strong limitation of safe-sites for seedling establishment reduces the importance of seed predation.

  17. The regulation of ant colony foraging activity without spatial information.

    Science.gov (United States)

    Prabhakar, Balaji; Dektar, Katherine N; Gordon, Deborah M

    2012-01-01

    Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

  18. Trade-offs in an ant-plant-fungus mutualism.

    Science.gov (United States)

    Orivel, Jérôme; Malé, Pierre-Jean; Lauth, Jérémie; Roux, Olivier; Petitclerc, Frédéric; Dejean, Alain; Leroy, Céline

    2017-03-15

    Species engaged in multiple, simultaneous mutualisms are subject to trade-offs in their mutualistic investment if the traits involved in each interaction are overlapping, which can lead to conflicts and affect the longevity of these associations. We investigate this issue via a tripartite mutualism involving an ant plant, two competing ant species and a fungus the ants cultivate to build galleries under the stems of their host plant to capture insect prey. The use of the galleries represents an innovative prey capture strategy compared with the more typical strategy of foraging on leaves. However, because of a limited worker force in their colonies, the prey capture behaviour of the ants results in a trade-off between plant protection (i.e. the ants patrol the foliage and attack intruders including herbivores) and ambushing prey in the galleries, which has a cascading effect on the fitness of all of the partners. The quantification of partners' traits and effects showed that the two ant species differed in their mutualistic investment. Less investment in the galleries (i.e. in fungal cultivation) translated into more benefits for the plant in terms of less herbivory and higher growth rates and vice versa. However, the greater vegetative growth of the plants did not produce a positive fitness effect for the better mutualistic ant species in terms of colony size and production of sexuals nor was the mutualist compensated by the wider dispersal of its queens. As a consequence, although the better ant mutualist is the one that provides more benefits to its host plant, its lower host-plant exploitation does not give this ant species a competitive advantage. The local coexistence of the ant species is thus fleeting and should eventually lead to the exclusion of the less competitive species. © 2017 The Author(s).

  19. Does Trichomes on the Plant Epidermic Surface Disturb Ants Locomotion?

    Directory of Open Access Journals (Sweden)

    Danon C. Cardoso

    2009-01-01

    Full Text Available Problem Statement: Many morphological characteristics, both physical and chemical, are used in the defense against herbivores on plants. Trichomes are structures used by plants as physics defense and when associated with glands combine physics and chemistry defense. Many species of ants are herbivores and use leaves and seeds, others ants use Extra Floral Nectars as a food resource, and the majority of the species are predators of other ants and other insects, and use plants as foraging substrate in search of prey. Likewise, on the assumption that ants feed preferentially in plants free of trichomes, we tested the hypothesis that trichomes plants clouded locomotion of ants. Approach: Experiments were carried out in the field using cotton to mimic the plants surface. Thirty traps for the treatment were assembled with cotton as well as other 30 experiments for the control (treatment without cotton. Each trap consisted of Petri dishes of 14,5 cm diameter with bait (sardine and honey in a disc (3 cm diameter in the center of the plate. Around the bait, 10 grams of cotton prepared uniformly were placed. Furthermore, morphometric analysis on the length of body and legs of ants was performed. Results: The number of ants which accessed baits in the center of Petri dishes in treatment with cotton was not statistically different of the number of accesses in the control treatment without cotton. The trichomes do not cloud locomotion of ants and that leg length is equal to or greater than body length. Conclusions/Recommendations: Data revealed that the trichomes do not cloud locomotion of ants; this allows the free walking of ants on the plants surface. However, glandular trichomes that combine physics and chemistry defense with release toxic and adhesives compounds when mechanically stressed may be more efficient in the defense against these insects.

  20. Indirect defense in a highly specific ant-plant mutualism

    Science.gov (United States)

    Grangier, Julien; Dejean, Alain; Malé, Pierre-Jean G.; Orivel, Jérôme

    2008-10-01

    Although associations between myrmecophytes and their plant ants are recognized as a particularly effective form of protective mutualism, their functioning remains incompletely understood. This field study examined the ant-plant Hirtella physophora and its obligate ant associate Allomerus decemarticulatus. We formulated two hypotheses on the highly specific nature of this association: (1) Ant presence should be correlated with a marked reduction in the amount of herbivory on the plant foliage; (2) ant activity should be consistent with the "optimal defense" theory predicting that the most vulnerable and valuable parts of the plant are the best defended. We validated the first hypothesis by demonstrating that for ant-excluded plants, expanding leaves, but also newly matured ones in the long term, suffered significantly more herbivore damage than ant-inhabited plants. We showed that A. decemarticulatus workers represent both constitutive and inducible defenses for their host, by patrolling its foliage and rapidly recruiting nestmates to foliar wounds. On examining how these activities change according to the leaves’ developmental stage, we found that the number of patrolling ants dramatically decreased as the leaves matured, while leaf wounds induced ant recruitment regardless of the leaf’s age. The resulting level of these indirect defenses was roughly proportional to leaf vulnerability and value during its development, thus validating our second hypothesis predicting optimal protection. This led us to discuss the factors influencing ant activity on the plant’s surface. Our study emphasizes the importance of studying both the constitutive and inducible components of indirect defense when evaluating its efficacy and optimality.

  1. Using pleometrosis (multiple queens) and pupae transplantation to boost weaver ant (Oecophylla smaragdina) colony growth in ant nurseries

    DEFF Research Database (Denmark)

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

    2011-01-01

    Weaver ants (Oecophylla spp.) are increasingly being used for biocontrol and are targeted for future production of insect protein in ant farms. An efficient production of live ant colonies may facilitate the utilization of these ants but the production of mature colonies is hampered by the long...... and no transplantation. Thus, in ant nurseries the use of multiple queens during nest founding as well as transplantation of pupae from foreign colonies may be utilised to decrease the time it takes to produce a colony ready for implementation....... time it takes for newly established colonies to grow to a suitable size. In this study we followed the growth of newly founded O. smaragdina colonies with 2, 3 or 4 founding queens during 12 days of development, following the transplantation of 0, 30 or 60 pupae from a mature donor colony. Colony...

  2. Desert ants achieve reliable recruitment across noisy interactions.

    Science.gov (United States)

    Razin, Nitzan; Eckmann, Jean-Pierre; Feinerman, Ofer

    2013-05-06

    We study how desert ants, Cataglyphis niger, a species that lacks pheromone-based recruitment mechanisms, inform each other about the presence of food. Our results are based on automated tracking that allows us to collect a large database of ant trajectories and interactions. We find that interactions affect an ant's speed within the nest. Fast ants tend to slow down, whereas slow ones increase their speed when encountering a faster ant. Faster ants tend to exit the nest more frequently than slower ones. So, if an ant gains enough speed through encounters with others, then she tends to leave the nest and look for food. On the other hand, we find that the probability for her to leave the nest depends only on her speed, but not on whether she had recently interacted with a recruiter that has found the food. This suggests a recruitment system in which ants communicate their state by very simple interactions. Based on this assumption, we estimate the information-theoretical channel capacity of the ants' pairwise interactions. We find that the response to the speed of an interacting nest-mate is very noisy. The question is then how random interactions with ants within the nest can be distinguished from those interactions with a recruiter who has found food. Our measurements and model suggest that this distinction does not depend on reliable communication but on behavioural differences between ants that have found the food and those that have not. Recruiters retain high speeds throughout the experiment, regardless of the ants they interact with; non-recruiters communicate with a limited number of nest-mates and adjust their speed following these interactions. These simple rules lead to the formation of a bistable switch on the level of the group that allows the distinction between recruitment and random noise in the nest. A consequence of the mechanism we propose is a negative effect of ant density on exit rates and recruitment success. This is, indeed, confirmed by our

  3. El periodista, ante la espiral de silencio

    OpenAIRE

    Dr. Fermín Galindo Arranz

    1998-01-01

    La percepción de la profesión periodística y de su influencia cambia mucho a lo largo del tiempo, de las coyunturas históricas y de los diferentes países y sociedades en los que desempeñan su labor. En un contexto mundial, la gravedad de las situaciones de riesgo periodístico se encuadran en situaciones políticas, económicas o sociales también conflictivas; es entonces cuando se suele reproducir con facilidad en la opinión pública el fenómeno de la espiral del silencio, ante el que inevitable...

  4. Overview of the Distribution, Habitat Association and Impact of Exotic Ants on Native Ant Communities in New Caledonia.

    Directory of Open Access Journals (Sweden)

    Maïa Berman

    Full Text Available Ants are among the most ubiquitous and harmful invaders worldwide, but there are few regional studies of their relationships with habitat and native ant communities. New Caledonia has a unique and diverse ant fauna that is threatened by exotic ants, but broad-scale patterns of exotic and native ant community composition in relation to habitat remain poorly documented. We conducted a systematic baiting survey of 56 sites representing the main New Caledonian habitat types: rainforest on ultramafic soils (15 sites, rainforest on volcano-sedimentary soils (13, maquis shrubland (15, Melaleuca-dominated savannas (11 and Acacia spirorbis thickets (2. We collected a total of 49 species, 13 of which were exotic. Only five sites were free of exotic species, and these were all rainforest. The five most abundant exotic species differed in their habitat association, with Pheidole megacephala associated with rainforests, Brachymyrmex cf. obscurior with savanna, and Wasmannia auropunctata and Nylanderia vaga present in most habitats. Anoplolepis gracilipes occurred primarily in maquis-shrubland, which contrasts with its rainforest affinity elsewhere. Multivariate analysis of overall ant species composition showed strong differentiation of sites according to the distribution of exotic species, and these patterns were maintained at the genus and functional group levels. Native ant composition differed at invaded versus uninvaded rainforest sites, in the absence of differences in habitat variables. Generalised Myrmicinae and Forest Opportunists were particularly affected by invasion. There was a strong negative relationship between the abundance of W. auropunctata and native ant abundance and richness. This emphasizes that, in addition to dominating many ant communities numerically, some exotic species, and in particular W. auropunctata, have a marked impact on native ant communities.

  5. Overview of the Distribution, Habitat Association and Impact of Exotic Ants on Native Ant Communities in New Caledonia.

    Science.gov (United States)

    Berman, Maïa; Andersen, Alan N; Hély, Christelle; Gaucherel, Cédric

    2013-01-01

    Ants are among the most ubiquitous and harmful invaders worldwide, but there are few regional studies of their relationships with habitat and native ant communities. New Caledonia has a unique and diverse ant fauna that is threatened by exotic ants, but broad-scale patterns of exotic and native ant community composition in relation to habitat remain poorly documented. We conducted a systematic baiting survey of 56 sites representing the main New Caledonian habitat types: rainforest on ultramafic soils (15 sites), rainforest on volcano-sedimentary soils (13), maquis shrubland (15), Melaleuca-dominated savannas (11) and Acacia spirorbis thickets (2). We collected a total of 49 species, 13 of which were exotic. Only five sites were free of exotic species, and these were all rainforest. The five most abundant exotic species differed in their habitat association, with Pheidole megacephala associated with rainforests, Brachymyrmex cf. obscurior with savanna, and Wasmannia auropunctata and Nylanderia vaga present in most habitats. Anoplolepis gracilipes occurred primarily in maquis-shrubland, which contrasts with its rainforest affinity elsewhere. Multivariate analysis of overall ant species composition showed strong differentiation of sites according to the distribution of exotic species, and these patterns were maintained at the genus and functional group levels. Native ant composition differed at invaded versus uninvaded rainforest sites, in the absence of differences in habitat variables. Generalised Myrmicinae and Forest Opportunists were particularly affected by invasion. There was a strong negative relationship between the abundance of W. auropunctata and native ant abundance and richness. This emphasizes that, in addition to dominating many ant communities numerically, some exotic species, and in particular W. auropunctata, have a marked impact on native ant communities.

  6. Testing the effects of ant invasions on non-ant arthropods with high-resolution taxonomic data.

    Science.gov (United States)

    Hanna, Cause; Naughton, Ida; Boser, Christina; Holway, David

    2015-10-01

    Invasions give rise to a wide range of ecological effects. Many invasions proceed without noticeable impacts on the resident biota, whereas others shift species composition and even alter ecosystem function. Ant invasions generate a broad spectrum of ecological effects, but controversy surrounds the extent of these impacts, especially with regard to how other arthropods are affected. This uncertainty in part results from the widespread use of low-resolution taxonomic data, which can mask the presence of other introduced species and make it difficult to isolate the effects of ant invasions on native species. Here, we use high-resolution taxonomic data to examine the effects of Argentine ant invasions on arthropods on Santa Cruz Island, California. We sampled arthropods in eight pairs of invaded and uninvaded plots and then collaborated with taxonomic experts to identify taxa in four focal groups: spiders, bark lice, beetles, and ants. Spiders, bark lice, and beetles made up ~40% of the 9868 non-ant arthropod individuals sampled; the majority of focal group arthropods were putatively native taxa. Although our results indicate strong negative effects of the Argentine ant on native ants, as is well documented, invaded and uninvaded plots did not differ with respect to the richness, abundance, or species composition of spiders, bark lice, and beetles. One common, introduced species of bark louse was more common in uninvaded plots than in invaded plots, and including this species into our analyses changed the relationship between bark louse richness vs. L. humile abundance from no relationship to a significant negative relationship. This case illustrates how failure to differentiate native and introduced taxa can lead to erroneous conclusions about the effects of ant invasions. Our results caution against unqualified assertions about the effects of ant invasions on non-ant arthropods, and more generally demonstrate that accurate assessments of invasion impacts depend on

  7. Chemical defense by the native winter ant (Prenolepis imparis against the invasive Argentine ant (Linepithema humile.

    Directory of Open Access Journals (Sweden)

    Trevor R Sorrells

    Full Text Available The invasive Argentine ant (Linepithema humile is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile.

  8. Chemical defense by the native winter ant (Prenolepis imparis) against the invasive Argentine ant (Linepithema humile).

    Science.gov (United States)

    Sorrells, Trevor R; Kuritzky, Leah Y; Kauhanen, Peter G; Fitzgerald, Katherine; Sturgis, Shelby J; Chen, Jimmy; Dijamco, Cheri A; Basurto, Kimberly N; Gordon, Deborah M

    2011-04-19

    The invasive Argentine ant (Linepithema humile) is established worldwide and displaces native ant species. In northern California, however, the native winter ant (Prenolepis imparis) persists in invaded areas. We found that in aggressive interactions between the two species, P. imparis employs a potent defensive secretion. Field observations were conducted at P. imparis nest sites both in the presence and absence of L. humile. These observations suggested and laboratory assays confirmed that P. imparis workers are more likely to secrete when outnumbered by L. humile. Workers of P. imparis were also more likely to secrete near their nest entrances than when foraging on trees. One-on-one laboratory trials showed that the P. imparis secretion is highly lethal to L. humile, causing 79% mortality. The nonpolar fraction of the secretion was chemically analyzed with gas chromatography/mass spectrometry, and found to be composed of long-chain and cyclic hydrocarbons. Chemical analysis of dissected P. imparis workers showed that the nonpolar fraction is derived from the Dufour's gland. Based on these conclusions, we hypothesize that this chemical defense may help P. imparis to resist displacement by L. humile.

  9. Plant defense, herbivory, and the growth of Cordia alliodora trees and their symbiotic Azteca ant colonies.

    Science.gov (United States)

    Pringle, Elizabeth G; Dirzo, Rodolfo; Gordon, Deborah M

    2012-11-01

    The effects of herbivory on plant fitness are integrated over a plant's lifetime, mediated by ontogenetic changes in plant defense, tolerance, and herbivore pressure. In symbiotic ant-plant mutualisms, plants provide nesting space and food for ants, and ants defend plants against herbivores. The benefit to the plant of sustaining the growth of symbiotic ant colonies depends on whether defense by the growing ant colony outpaces the plant's growth in defendable area and associated herbivore pressure. These relationships were investigated in the symbiotic mutualism between Cordia alliodora trees and Azteca pittieri ants in a Mexican tropical dry forest. As ant colonies grew, worker production remained constant relative to ant-colony size. As trees grew, leaf production increased relative to tree size. Moreover, larger trees hosted lower densities of ants, suggesting that ant-colony growth did not keep pace with tree growth. On leaves with ants experimentally excluded, herbivory per unit leaf area increased exponentially with tree size, indicating that larger trees experienced higher herbivore pressure per leaf area than smaller trees. Even with ant defense, herbivory increased with tree size. Therefore, although larger trees had larger ant colonies, ant density was lower in larger trees, and the ant colonies did not provide sufficient defense to compensate for the higher herbivore pressure in larger trees. These results suggest that in this system the tree can decrease herbivory by promoting ant-colony growth, i.e., sustaining space and food investment in ants, as long as the tree continues to grow.

  10. Trait-Mediated Indirect Effects of Phorid Flies on Ants

    Directory of Open Access Journals (Sweden)

    Hsun-Yi Hsieh

    2012-01-01

    Full Text Available This paper provides a synthesis of the ecological impact of phorid fly parasitoids on ants. We find the most important impact of phorids on ants to be trait-mediated effects. Phorids diminish the foraging activity of ants, frequently reducing the number and average size of foragers and reducing the amount of food retrieved by a colony. However, ants' coping mechanisms include changing foraging site and time. Phorids can also affect competition, especially through changes in the ability of the host to win in exploitative competition. Factors such as microclimate, resource size, and habitat complexity interact with phorids to change their effect on competition. By being highly specific and attacking ants high in the competitive hierarchy, phorids can alter the linear nature of the competitive transitivity, and by reducing the number of foragers, they can change the discovery-dominance tradeoff that is observed in some ant communities. Trait-mediated effects of phorids also cascade to other trophic levels. As an example, we discuss the trait-mediated cascade of phorids on the Azteca instabilis system in coffee. In this system, by reducing the foraging activity of A. instabilis, phorids reduce the direct and indirect biological control impact of the ant in the coffee agroecosystem.

  11. The diversity of microorganisms associated with Acromyrmex leafcutter ants

    Directory of Open Access Journals (Sweden)

    Boomsma Jacobus J

    2002-05-01

    Full Text Available Abstract Background Molecular biological techniques are dramatically changing our view of microbial diversity in almost any environment that has so far been investigated. This study presents a systematic survey of the microbial diversity associated with a population of Acromyrmex leafcutter ants. In contrast to previous studies on social insects, which targeted specific groups of symbionts occurring in the gut (termites, Tetraponera ants or in specialised cells (Camponotus ants the objective of our present study was to do a total screening of all possible micro-organisms that can be found inside the bodies of these leafcutter ants. Results We amplified, cloned and sequenced SSU rRNA encoding gene fragments from 9 microbial groups known to have insect-associated representatives, and show that: (1 representatives of 5 out of 9 tested groups are present, (2 mostly several strains per group are present, adding up to a total of 33 different taxa. We present the microbial taxa associated with Acromymex ants in a phylogenetic context (using sequences from GenBank to assess and illustrate to which known microorganisms they are closely related. The observed microbial diversity is discussed in the light of present knowledge on the evolutionary history of Acromyrmex leafcutter ants and their known mutualistic and parasitic symbionts. Conclusions The major merits of the screening approach documented here is its high sensitivity and specificity, which allowed us to identify several microorganisms that are promising candidates for further study of their interactions with Acromyrmex leafcutter ants or their gardens.

  12. Ant-mediated seed dispersal in a warmed world.

    Science.gov (United States)

    Stuble, Katharine L; Patterson, Courtney M; Rodriguez-Cabal, Mariano A; Ribbons, Relena R; Dunn, Robert R; Sanders, Nathan J

    2014-01-01

    Climate change affects communities both directly and indirectly via changes in interspecific interactions. One such interaction that may be altered under climate change is the ant-plant seed dispersal mutualism common in deciduous forests of eastern North America. As climatic warming alters the abundance and activity levels of ants, the potential exists for shifts in rates of ant-mediated seed dispersal. We used an experimental temperature manipulation at two sites in the eastern US (Harvard Forest in Massachusetts and Duke Forest in North Carolina) to examine the potential impacts of climatic warming on overall rates of seed dispersal (using Asarum canadense seeds) as well as species-specific rates of seed dispersal at the Duke Forest site. We also examined the relationship between ant critical thermal maxima (CTmax) and the mean seed removal temperature for each ant species. We found that seed removal rates did not change as a result of experimental warming at either study site, nor were there any changes in species-specific rates of seed dispersal. There was, however, a positive relationship between CTmax and mean seed removal temperature, whereby species with higher CTmax removed more seeds at hotter temperatures. The temperature at which seeds were removed was influenced by experimental warming as well as diurnal and day-to-day fluctuations in temperature. Taken together, our results suggest that while temperature may play a role in regulating seed removal by ants, ant plant seed-dispersal mutualisms may be more robust to climate change than currently assumed.

  13. Artificial ants deposit pheromone to search for regulatory DNA elements

    Directory of Open Access Journals (Sweden)

    Liu Yunlong

    2006-08-01

    Full Text Available Abstract Background Identification of transcription-factor binding motifs (DNA sequences can be formulated as a combinatorial problem, where an efficient algorithm is indispensable to predict the role of multiple binding motifs. An ant algorithm is a biology-inspired computational technique, through which a combinatorial problem is solved by mimicking the behavior of social insects such as ants. We developed a unique version of ant algorithms to select a set of binding motifs by considering a potential contribution of each of all random DNA sequences of 4- to 7-bp in length. Results Human chondrogenesis was used as a model system. The results revealed that the ant algorithm was able to identify biologically known binding motifs in chondrogenesis such as AP-1, NFκB, and sox9. Some of the predicted motifs were identical to those previously derived with the genetic algorithm. Unlike the genetic algorithm, however, the ant algorithm was able to evaluate a contribution of individual binding motifs as a spectrum of distributed information and predict core consensus motifs from a wider DNA pool. Conclusion The ant algorithm offers an efficient, reproducible procedure to predict a role of individual transcription-factor binding motifs using a unique definition of artificial ants.

  14. Contact rate modulates foraging efficiency in leaf cutting ants.

    Science.gov (United States)

    Bouchebti, S; Ferrere, S; Vittori, K; Latil, G; Dussutour, A; Fourcassié, V

    2015-12-21

    Lane segregation is rarely observed in animals that move in bidirectional flows. Consequently, these animals generally experience a high rate of head-on collisions during their journeys. Although these collisions have a cost (each collision induces a delay resulting in a decrease of individual speed), they could also have a benefit by promoting information transfer between individuals. Here we explore the impact of head-on collisions in leaf-cutting ants moving on foraging trails by artificially decreasing the rate of head-on collisions between individuals. We show that head-on collisions do not influence the rate of recruitment in these ants but do influence foraging efficiency, i.e. the proportion of ants returning to the nest with a leaf fragment. Surprisingly, both unladen and laden ants returning to the nest participate in the modulation of foraging efficiency: foraging efficiency decreases when the rate of contacts with both nestbound laden or unladen ants decreases. These results suggest that outgoing ants are able to collect information from inbound ants even when these latter do not carry any leaf fragment and that this information can influence their foraging decisions when reaching the end of the trail.

  15. Learning and perceptual similarity among cuticular hydrocarbons in ants.

    Science.gov (United States)

    Bos, Nick; Dreier, Stephanie; Jørgensen, Charlotte G; Nielsen, John; Guerrieri, Fernando J; d'Ettorre, Patrizia

    2012-01-01

    Nestmate recognition in ants is based on perceived differences in a multi-component blend of hydrocarbons that are present on the insect cuticle. Although supplementation experiments have shown that some classes of hydrocarbons, such as methyl branched alkanes and alkenes, have a salient role in nestmate recognition, there was basically no information available on how ants detect and perceive these molecules. We used a new conditioning procedure to investigate whether individual carpenter ants could associate a given hydrocarbon (linear or methyl-branched alkane) to sugar reward. We then studied perceptual similarity between a hydrocarbon previously associated with sugar and a novel hydrocarbon. Ants learnt all hydrocarbon-reward associations rapidly and with the same efficiency, regardless of the structure of the molecules. Ants could discriminate among a large number of pairs of hydrocarbons, but also generalised. Generalisation depended both on the structure of the molecule and the animal's experience. For linear alkanes, generalisation was observed when the novel molecule was smaller than the conditioned one. Generalisation between pairs of methyl-alkanes was high, while generalisation between hydrocarbons that differed in the presence or absence of a methyl group was low, suggesting that chain length and functional group might be coded independently by the ant olfactory system. Understanding variations in perception of recognition cues in ants is necessary for the general understanding of the mechanisms involved in social recognition processes based on chemical cues.

  16. Collective strategy for obstacle navigation during cooperative transport by ants.

    Science.gov (United States)

    McCreery, Helen F; Dix, Zachary A; Breed, Michael D; Nagpal, Radhika

    2016-11-01

    Group cohesion and consensus have primarily been studied in the context of discrete decisions, but some group tasks require making serial decisions that build on one another. We examine such collective problem solving by studying obstacle navigation during cooperative transport in ants. In cooperative transport, ants work together to move a large object back to their nest. We blocked cooperative transport groups of Paratrechina longicornis with obstacles of varying complexity, analyzing groups' trajectories to infer what kind of strategy the ants employed. Simple strategies require little information, but more challenging, robust strategies succeed with a wider range of obstacles. We found that transport groups use a stochastic strategy that leads to efficient navigation around simple obstacles, and still succeeds at difficult obstacles. While groups navigating obstacles preferentially move directly toward the nest, they change their behavior over time; the longer the ants are obstructed, the more likely they are to move away from the nest. This increases the chance of finding a path around the obstacle. Groups rapidly changed directions and rarely stalled during navigation, indicating that these ants maintain consensus even when the nest direction is blocked. Although some decisions were aided by the arrival of new ants, at many key points, direction changes were initiated within the group, with no apparent external cause. This ant species is highly effective at navigating complex environments, and implements a flexible strategy that works for both simple and more complex obstacles. © 2016. Published by The Company of Biologists Ltd.

  17. Interactions Increase Forager Availability and Activity in Harvester Ants.

    Science.gov (United States)

    Pless, Evlyn; Queirolo, Jovel; Pinter-Wollman, Noa; Crow, Sam; Allen, Kelsey; Mathur, Maya B; Gordon, Deborah M

    2015-01-01

    Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  18. Species richness, equitability, and abundance of ants in disturbed landscapes

    Science.gov (United States)

    Graham, J.H.; Krzysik, A.J.; Kovacic, D.A.; Duda, J.J.; Freeman, D.C.; Emlen, J.M.; Zak, J.C.; Long, W.R.; Wallace, M.P.; Chamberlin-Graham, C.; Nutter, J.P.; Balbach, H.E.

    2009-01-01

    Ants are used as indicators of environmental change in disturbed landscapes, often without adequate understanding of their response to disturbance. Ant communities in the southeastern United States displayed a hump-backed species richness curve against an index of landscape disturbance. Forty sites at Fort Benning, in west-central Georgia, covered a spectrum of habitat disturbance (military training and fire) in upland forest. Sites disturbed by military training had fewer trees, less canopy cover, more bare ground, and warmer, more compact soils with shallower A-horizons. We sampled ground-dwelling ants with pitfall traps, and measured 15 habitat variables related to vegetation and soil. Ant species richness was greatest with a relative disturbance of 43%, but equitability was greatest with no disturbance. Ant abundance was greatest with a relative disturbance of 85%. High species richness at intermediate disturbance was associated with greater within-site spatial heterogeneity. Species richness was also associated with intermediate values of the normalized difference vegetation index (NDVI), a correlate of net primary productivity (NPP). Available NPP (the product of NDVI and the fraction of days that soil temperature exceeded 25 ??C), however, was positively correlated with species richness, though not with ant abundance. Species richness was unrelated to soil texture, total ground cover, and fire frequency. Ant species richness and equitability are potential state indicators of the soil arthropod community. Moreover, equitability can be used to monitor ecosystem change. ?? 2008 Elsevier Ltd.

  19. Modelling of self-driven particles: Foraging ants and pedestrians

    Science.gov (United States)

    Nishinari, Katsuhiro; Sugawara, Ken; Kazama, Toshiya; Schadschneider, Andreas; Chowdhury, Debashish

    2006-12-01

    Models for the behavior of ants and pedestrians are studied in a unified way in this paper. Each ant follows pheromone put by preceding ants, hence creating a trail on the ground, while pedestrians also try to follow others in a crowd for efficient and safe walking. These following behaviors are incorporated in our stochastic models by using only local update rules for computational efficiency. It is demonstrated that the ant trail model shows a unusual non-monotonic dependence of the average speed of the ants on their density, which can be well analyzed by the zero-range process. We also show that this anomalous behavior is clearly observed in an experiment of multiple robots. Next, the relation between the ant trail model and the floor field model for studying evacuation dynamics of pedestrians is discussed. The latter is regarded as a two-dimensional generalization of the ant trail model, where the pheromone is replaced by footprints. It is shown from simulations that small perturbations to pedestrians will sometimes avoid congestion and hence allow safe evacuation.

  20. Ant colonies and foraging line dynamics: Modeling, experiments and computations

    Science.gov (United States)

    Rossi, Louis

    2005-11-01

    Ants are one of several types of insects that form robust and complex societies, and as such, provide rich theoretical ground for the exploration and understanding of collective dynamics and the behaviorial parameters that drive the dynamics. Many species of ants are nearly or completely blind, so they interact locally through behaviorial cues with nearby ants, and through pheromone trails left by other ants. Consistent with biological observation, two populations of ants are modeled, those seeking food and those returning to the nest with food. A simple constitutive model relating ant densities to pheromone concentrations yields a system of equations describing two interacting fluids and predicts left- and right-moving traveling waves. All the model parameters can be reduced to two Froude numbers describing the ratio between a chemical potential and the kinetic energy of the traveling ants. Laboratory experiments on Tetramorium caespitum (L) clearly indicate left and right-moving traveling density waves in agreement with the mathematical model. We focus on understanding the evolutionary utility of the traveling waves, and the optimality of the Froude numbers and other parameters.