1,934 research outputs found

    Polynomial scaling of the quantum approximate optimization algorithm for ground-state preparation of the fully connected p -spin ferromagnet in a transverse field

    Get PDF
    We show that the quantum approximate optimization algorithm (QAOA) can construct, with polynomially scaling resources, the ground state of the fully connected p-spin Ising ferromagnet, a problem that notoriously poses severe difficulties to a vanilla quantum annealing (QA) approach due to the exponentially small gaps encountered at first-order phase transition for p≄3. For a target ground state at arbitrary transverse field, we find that an appropriate QAOA parameter initialization is necessary to achieve good performance of the algorithm when the number of variational parameters 2P is much smaller than the system size N because of the large number of suboptimal local minima. Instead, when P exceeds a critical value PN∗N, the structure of the parameter space simplifies, as all minima become degenerate. This allows achieving the ground state with perfect fidelity with a number of parameters scaling extensively with N and with resources scaling polynomially with N

    Performance of Geant4 in simulating semiconductor particle detector response in the energy range below 1 MeV

    Full text link
    Geant4 simulations play a crucial role in the analysis and interpretation of experiments providing low energy precision tests of the Standard Model. This paper focuses on the accuracy of the description of the electron processes in the energy range between 100 and 1000 keV. The effect of the different simulation parameters and multiple scattering models on the backscattering coefficients is investigated. Simulations of the response of HPGe and passivated implanted planar Si detectors to \beta{} particles are compared to experimental results. An overall good agreement is found between Geant4 simulations and experimental data

    Reinforcement-learning-assisted quantum optimization

    Get PDF
    We propose a reinforcement learning (RL) scheme for feedback quantum control within the quantum approximate optimization algorithm (QAOA). We reformulate the QAOA variational minimization as a learning task, where an RL agent chooses the control parameters for the unitaries, given partial information on the system. Such an RL scheme finds a policy converging to the optimal adiabatic solution of the quantum Ising chain that can also be successfully transferred between systems with different sizes, even in the presence of disorder. This allows for immediate experimental verification of our proposal on more complicated models: The RL agent is trained on a small control system, simulated on classical hardware, and then tested on a larger physical sample

    Living on the edge: Space use of Eurasian red squirrels in marginal high-elevation habitat.

    Get PDF
    In marginal habitats located at the edge of a species\u2019 range, environmental conditions are frequently extreme and individuals may be subject to different selective pressures compared to central populations. These so-called edge or marginal populations tend to have lower densities and reproductive rates than populations located in more suitable habitats, but little is known about local adaptations in spacing behavior. We studied space use and social organization in a population of Eurasian red squirrels (Sciurus vulgaris) in a high-elevation marginal habitat of dwarf mountain pine (Pinus mugo) and compared it with spacing patterns in high-quality Scots pine (Pinus sylvestris) forest at lower-elevation. Home ranges and core areas were larger in the marginal habitat. In both habitats, males used larger home ranges than females, but sex differences in core area size were significant only in the edge population. Patterns of core area overlap were similar in both habitats with intra-sexual territoriality among adult females and higher degrees of inter-sexual overlap, typical for the species throughout its range. However, low densities in the edge population resulted in higher female by males overlap in spring-summer, suggesting males increased home ranges and core areas during mating season to augment access to estrus females. Thus, in the marginal habitat, with low food abundance and low population densities, linked with extreme winter conditions, squirrels, especially males, used large home ranges. Finally, squirrels responded more strongly to variation in food availability (inverse relation between home range size and seed abundance), and even to fluctuations in density (inverse relation between core area size and density of animals of the same sex), in the marginal than in the high-quality habitat, suggesting high behavioral plasticity to respond to the ecological constraints in marginal habitats

    Determination of antimicrobial susceptibility patterns of Nocardia spp. from clinical specimens by Etest

    Get PDF
    ABSTRACTSusceptibilities to 11 antimicrobial agents were determined by Etest for 93 Nocardia isolates from clinical specimens and 15 type strains belonging to different Nocardia spp. All isolates were susceptible to trimethoprim-sulphamethoxazole, amikacin and linezolid, but susceptibilities of the various Nocardia spp. to ÎČ-lactams, aminoglycosides, ciprofloxacin and clarithromycin varied markedly. Overall, there was a good correlation between the drug resistance patterns and the species identification established by conventional phenotypic tests and 16S rDNA sequencing. Among the different species encountered, Nocardia farcinica and Nocardia brasiliensis displayed the most multiresistant profiles, with resistance to imipenem occurring mainly among isolates of N. brasiliensis and Nocardia abscessus. The species variability in susceptibility profiles and the numerous recent taxonomic changes means that in-vitro susceptibility tests may be a complementary tool for the identification of Nocardia isolates from human clinical specimens. Further studies on a larger number of species from more diverse geographical sources, including species that are found less commonly among clinical isolates, are required to validate and extend the results

    Ion cyclotron wall conditioning experiments on Tore Supra in presence of the toroidal magnetic field

    Get PDF
    Wall conditioning techniques applicable in the presence of the high toroidal magnetic field will be required for the operation of ITER for tritium removal, isotopic ratio control and recovery to normal operation after disruptions. Recently ion cyclotron wall conditioning (ICWC) experiments have been carried out on Tore Supra in order to assess the efficiency of this technique in ITER relevant conditions. The ICRF discharges were operated in He/H-2 Mixtures at the Tore Supra nominal field (3.8 T) and a RF frequency of 48 MHz, i.e. within the ITER operational space. RF pulses of 60 s (max.) were applied using a standard Tore Supra two-strap resonant double loop antenna in ICWC mode, operated either in pi or 0-phasing with a noticeable improvement of the RF coupling in the latter case. In order to assess the efficiency of the technique for the control of isotopic ratio the wall was first preloaded using a D-2 glow discharge. After 15 minutes of ICWC in He/H-2 gas mixtures the isotopic ratio was altered from 4% to 50% at the price of an important H implantation into the walls. An overall analysis comparing plasma production and the conditioning efficiency as a function of discharge parameters is given

    Macroparasite fauna of alien grey squirrels (Sciurus carolinensis): composition, variability and implications for native species.

    Get PDF
    Introduced hosts populations may benefit of an "enemy release" through impoverishment of parasite communities made of both few imported species and few acquired local ones. Moreover, closely related competing native hosts can be affected by acquiring introduced taxa (spillover) and by increased transmission risk of native parasites (spillback). We determined the macroparasite fauna of invasive grey squirrels (Sciurus carolinensis) in Italy to detect any diversity loss, introduction of novel parasites or acquisition of local ones, and analysed variation in parasite burdens to identify factors that may increase transmission risk for native red squirrels (S. vulgaris). Based on 277 grey squirrels sampled from 7 populations characterised by different time scales in introduction events, we identified 7 gastro-intestinal helminths and 4 parasite arthropods. Parasite richness is lower than in grey squirrel's native range and independent from introduction time lags. The most common parasites are Nearctic nematodes Strongyloides robustus (prevalence: 56.6%) and Trichostrongylus calcaratus (6.5%), red squirrel flea Ceratophyllus sciurorum (26.0%) and Holarctic sucking louse Neohaematopinus sciuri (17.7%). All other parasites are European or cosmopolitan species with prevalence below 5%. S. robustus abundance is positively affected by host density and body mass, C. sciurorum abundance increases with host density and varies with seasons. Overall, we show that grey squirrels in Italy may benefit of an enemy release, and both spillback and spillover processes towards native red squirrels may occur

    Levels of testosterone, progesterone and oestradiol in pregnant-lactating does in relation to aggression during group housing

    Get PDF
    [EN] The neuroendocrine regulation of rabbit maternal behaviour has been explored in detail. However, little is yet known about the hormonal regulation of aggression in concurrently pregnant-lactating does, a reproductive condition that prevails during group housing of rabbits on farms. Therefore, in this study we determined the relation between a) the levels of progesterone, testosterone, and oestradiol during lactation; b) the anogenital distance at artificial insemination; and c) the timing of grouping with the intensity of agonistic behaviour, published previously. We performed four consecutive trials, where three groups of eight does each were artificially inseminated on day 10 postpartum (pp) and grouped on either day 12, 18 or 22 pp. Using Dipetalogaster maxima, a reduviid blood-sucking bug, we collected blood samples during the pregnant-lactating phase (days 13, 15, 17, 19, 21, 23 pp) on one or two randomly chosen does per treatment group. Testosterone levels varied little across the pregnant-lactating phase, agreeing with results from pregnant-only rabbits, while progesterone levels increased from day 3 (=13 dpp) to day 7 (=17 dpp) and remained unchanged until day 13 (=23 dpp) of pregnancy. All oestradiol concentrations fell below the limit of detection. Overall, all concentrations were slightly lower in comparison to rabbit studies with pregnantonly does. The agonistic behaviour was not related to the respective hormonal concentrations at grouping. In conclusion, the time point of grouping does after artificial insemination (AI) in the semi-group housing system only had a weak influence on aggression and the hormonal profile did not indicate an optimum time for grouping.Federal Food Safety and Veterinary Office (BLV, Project No. 2.18.04)Braconnier, M.; GonzĂĄlez-Mariscal, G.; Wauters, J.; Gebhardt-Henrich, SG. (2021). Levels of testosterone, progesterone and oestradiol in pregnant-lactating does in relation to aggression during group housing. World Rabbit Science. 29(4):247-261. https://doi.org/10.4995/wrs.2021.14897OJS247261294Aguilar-Roblero R., GonzĂĄlez-Mariscal G. 2020. Behavioral, neuroendocrine and physiological indicators of the circadian biology of male and female rabbits. Eur. J. Neurosci., 51: 429-453. https://doi.org/10.1111/ejn.14265Albert D.J., Jonik R.H., Walsh M.L. 1990. Hormone-Dependent Aggression in Female Rats: Testosterone Implants Attenuate the Decline in Aggression Following Ovariectomy I. Physiol. Behav., 47, 659-664. https://doi.org/10.1016/0031-9384(90)90074-EAndrist C.A., Bigler L.M., WĂŒrbel H., Roth B.A. 2012. Effects of group stability on aggression, stress and injuries in breeding rabbits. Appl. Anim. Behav. Sci., 142: 182-188. https://doi.org/10.1016/j.applanim.2012.10.017Andrist C.A., van den Borne B.H.P., Bigler L.M., Buchwalder T., Roth B.A. 2013. Epidemiologic survey in Swiss group-housed breeding rabbits: Extent of lesions and potential risk factors. Prev. Vet. Med., 108: 218-224. https://doi.org/10.1016/j.prevetmed.2012.07.015Arias-Álvarez M., GarcĂ­a-GarcĂ­a R.M., Torres-Rovira L., GonzĂĄlez- Bulnes A., Rebollar P.G., Lorenzo P.L. 2010. Influence of hormonal and nonhormonal estrus synchronization methods on follicular and oocyte quality in primiparous lactating does at early postpartum period. Theriogenology, 73: 26-35. https://doi.org/10.1016/j.theriogenology.2009.07.017BĂĄnszegi O., AltbĂ€cker V., BilkĂł Á. 2009. Intrauterine position influences anatomy and behavior in domestic rabbits. Physiol. Behav., 98: 258-262. https://doi.org/10.1016/j.physbeh.2009.05.016BĂĄnszegi O., Szenczi P., Dombay K., BilkĂł Á., AltbĂ€cker V. 2012. Anogenital distance as a predictor of attractiveness, litter size and sex ratio of rabbit does. Physiol. Behav., 105: 1226-1230. https://doi.org/10.1016/j.physbeh.2012.01.002Beehner J.C., Phillips-Conroy J.E., Whitten P.L. 2005. Female testosterone, dominance rank, and aggression in an Ethiopian population of hybrid baboons. Am. J. Primatol., 67, 101-119. https://doi.org/10.1002/ajp.20172Bill J., Rauterberg S., Herbrandt S., Ligges U., Kemper N., Fels M., Agonistic behavior and social hierarchy in female domestic rabbits kept in semi-groups. J. Vet. Behav., 38: 21-31. https://doi.org/10.1016/j.jveb.2020.03.004Braconnier M., GĂłmez Y., Gebhardt-Henrich S.G. 2020. Different regrouping schedules in semi group-housed rabbit does: Effects on agonistic behaviour, stress and lesions. Appl. Anim. Behav. Sci., 228: 105024. https://doi.org/10.1016/j.applanim.2020.105024BTS. 2019. https://www.blw.admin.ch/blw/de/home/instrumente/direktzahlungen/produktionssystembeitraege/tierwohlbeitraege.html.Buijs S., Maertens L., Hermans K., Vangeyte J., AndrĂ© F., Tuyttens M. 2015. Behaviour, wounds, weight loss and adrenal weight of rabbit does as affected by semigroup housing. Appl. Anim. Behav. Sci., 172: 44-51. https://doi.org/10.1016/j.applanim.2015.09.003Buijs S., Vangeyte J., Tuyttens F.A.M. 2016. Effects of communal rearing and group size on breeding rabbits' post-grouping behaviour and its relation to anogenital distance. Appl. Anim. Behav. Sci., 182: 53-60. https://doi.org/10.1016/j.applanim.2016.06.005Carnaby K., Painer J., Söderberg A., Gavier-WidĂšn D., Göritz F., Dehnhard M., Jewgenow K. 2012. Histological and endocrine characterization of the annual luteal activity in Eurasian Lynx (Lynx lynx). Reproduction, 10.1530 / REP-12-0166 144: 477-483. https://doi.org/10.1530/REP-12-0166Chu L.R., Garner J.P., Mench J.A., 2004. A behavioral comparison of New Zealand White rabbits (Oryctolagus cuniculus) housed individually or in pairs in conventional laboratory cages. Appl. Anim. Behav. Sci., 85: 121-139. https://doi.org/10.1016/j.applanim.2003.09.011Dal Bosco A., Mugnai C., Martino M., SzendrƑ Z., Mattioli S., Cambiotti V., Cartoni Mancinelli A., Moscati L., Castellini C. 2019. Housing Rabbit Does in a Combi System with Removable Walls: Effect on Behaviour and Reproductive Performance. Animals, 9: 528-528. https://doi.org/10.3390/ani9080528Davis E.S., Marler C.A. 2003. The progesterone challenge: steroid hormone changes following a simulated territorial intrusion in female Peromyscus californicus. Horm. Behav., Special Issue on Aggressive and Violent Behavior, 44: 185-198. https://doi.org/10.1016/S0018-506X(03)00128-4Dehnhard M., Naidenko S., Frank A., Braun B., Göritz F., Jewgenow K. 2008. Non-invasive Monitoring of Hormones: A Tool to Improve Reproduction in Captive Breeding of the Eurasian Lynx. Reprod. Domest. Anim., 43: 74-82. https://doi.org/10.1111/j.1439-0531.2008.01145.xDenenberg V.H., Sawin P.B., Frommer G.P., Ross S. 1958. Genetic, physiological and behavioral background of reproduction in the rabbit: IV. An analysis of maternal behavior at successive parturitions. Behaviour 13: 131-142. https://doi.org/10.1163/156853958X00073Drickamer L.C. 1996. Intra-uterine position and anogenital distance in house mice: consequences under field conditions. Anim. Behav., 51: 925-934. https://doi.org/10.1006/anbe.1996.0096DuĆĄek A., BartoĆĄ L. 2012. Variation in Ano-Genital Distance in Spontaneously Cycling Female Mice. Reprod. Domest. Anim., 47: 984-987. https://doi.org/10.1111/j.1439-0531.2012.02003.xFortun L., Prunier A., Lebas F. 1993. Effects of lactation on fetal survival and development in rabbit does mated shortly after parturition. J. Anim. Sci., 71: 1882-1886. https://doi.org/10.2527/1993.7171882xGobikrushanth M., BruinjĂ© T.C., Colazo M.G., Butler S.T., Ambrose D.J. 2017. Characterization of anogenital distance and its relationship to fertility in lactating Holstein cows. J. Dairy Sci., 100: 9815-9823. https://doi.org/10.3168/jds.2017-13033GonzĂĄlez-Mariscal G., DĂ­az-SĂĄnchez V., Melo A.I., Beyer C., Rosenblatt J.S. 1994. Maternal behavior in New Zealand white rabbits: Quantification of somatic events, motor patterns, and steroid plasma levels. Physiol. Behav., 55: 1081-1089. https://doi.org/10.1016/0031-9384(94)90391-3GonzĂĄlez-Mariscal G., JimĂ©nez P., Beyer C., Rosenblatt J.S. 2003. Androgens stimulate specific aspects of maternal nestbuilding and reduce food intake in rabbits. Horm. Behav., 43: 312-317. https://doi.org/10.1016/S0018-506X(02)00046-6GonzĂĄlez-Mariscal G., Gallegos J.A., Sierra-Ramirez A., Flores J.G. 2009. Impact of concurrent pregnancy and lactation on maternal nest- building, estradiol and progesterone concentrations in rabbits. World Rabbit Sci., 17: 145-152. https://doi.org/10.4995/wrs.2009.654GonzĂĄlez-Mariscal G., Lemus A.C., Vega-GonzĂĄlez A., Aguilar-Roblero A. 2013a. Litter size determines circadian periodicity of nursing in rabbits. Chronobiol. Int., 30: 711-718. https://doi.org/10.3109/07420528.2013.784769GonzĂĄlez-Mariscal G., Toribio A., Gallegos-Huicochea J.A., Serrano-Meneses M.A. 2013b. The characteristics of suckling stimulation determine the daily duration of motheryoung contact and milk output in rabbits. Dev. Psychobiol. 55: 809-817. https://doi.org/10.1002/dev.21071GonzĂĄlez-Mariscal G., Gallegos J.A. 2014. The maintenance and termination of maternal behavior in rabbits: Involvement of suckling and progesterone. Physiol. Behav., 124: 72-76. https://doi.org/10.1016/j.physbeh.2013.10.031GonzĂĄlez-Mariscal G., Caba M., MartĂ­nez-GĂłmez M., Bautista A., Hudson R. 2016. Mothers and offspring: The rabbit as a model system in the study of mammalian maternal behavior and sibling interactions. Horm. Behav., 77: 30-41. https://doi.org/10.1016/j.yhbeh.2015.05.011GonzĂĄlez-Mariscal G., Sisto Burt A., Nowak R. 2017. Behavioral and neuroendocrine indicators of well-being in farm and laboratory mammals. Pfaff D. & JoĂ«lls M., eds. "Hormones, Brain and Behavior" 3a ed. Elsevier, 454-485. https://doi.org/10.1016/B978-0-12-803592-4.00017-1Graf S., Bigler L., Failing K., WĂŒrbel H., Buchwalder T. 2011. Regrouping rabbit does in a familiar or novel pen: Effects on agonistic behaviour, injuries and core body temperature. Appl. Anim. Behav. Sci., 135: 121-127. https://doi.org/10.1016/j.applanim.2011.10.009Hein D.J. 2019. Labordiagnostik bei KleinsĂ€ugern: PrĂ€analytik und tierartspezifische Befundung. SchlĂŒtersche. Hein J. 2014. Blutentnahme und Venenverweilkatheter beim Kaninchen. kleintier konkret 17: 23-25. https://doi.org/10.1055/s-0034-1384446Hoffman K.L., MartĂ­nez-Alvarez E., Rueda-Morales R.I. 2009. The inhibition of female rabbit sexual behavior by progesterone: Progesterone receptor-dependent and-independent effects. Horm. Behav., 55: 84-92. https://doi.org/10.1016/j.yhbeh.2008.08.011Holst D. von, Hutzelmeyer H., Kaetzke P., Khaschei M., Rödel H.G. 2002. Social rank, fecundity and lifetime reproductive success in wild European rabbits (Oryctolagus cuniculus). Behav. Ecol. Sociobiol., 51, 245-254. https://doi.org/10.1007/s00265-001-0427-1Hudson R., Shaal B., BilkĂł Á., AltbĂ€cker V. 1996. Just three minutes a day: The behaviour of young rabbits viewed in the context of limited maternal care. In Proc.: 6th World Rabbit Congress, July 1996, Toulouse, France, 2: 395-403.Hudson R., Shaal B., MartĂ­nez-GĂłmez M., Distel H. 2000. Mother-young relations in the European rabbit: physiological and behavioural locks and keys. World Rabbit Science 8: 85-90. https://doi.org/10.4995/wrs.2000.424Kosowska B., StrzaƂa T., Moska M., Ratajszczak R., Dobosz T. 2015. Cytogenetic Examination of South American Tapirs, Tapirus Terrestris (Perissodactyla, Tapiridae), from the Wroclaw Zoological Garden. Vestnik Zoologii, 49: 529-536.Lebas F., Coudert P.,. de Rochambeau H.,. Thebault R.G. 1997. The rabbit - Husbandry, health and production. FAO Animal Production and Health Series No. 21.Maertens L., Rommers J., Jacquet M. 2011. Le logement des lapins en parcs, une alternative pour les cages classiques dans un systĂšme "duo"? [Combi-park housing of females, an alternative for the classical cages when using the "duo" management system?]. 14Ăšmes JournĂ©es de la Recherche Cunicole, 85-88.Mann M.A., Svare B. 1982. Factors influencing pregnancy induced aggression in mice. Behav. Neural Biol., 36: 242-258. https://doi.org/10.1016/S0163-1047(82)90867-6Mann M.A., Konen C., Svare B. 1984. The role of progesterone in pregnancy-induced aggression in mice. Horm. Behav., 18: 140-160. https://doi.org/10.1016/0018-506X(84)90039-4Markvardsen S.N., Kjelgaard-Hansen M., Ritz C., SØrensen D.B. 2012. Less invasive blood sampling in the animal laboratory: Clinical chemistry and haematology of blood obtained by the triatominae bug Dipetalogaster maximus. Lab. Anim., 46: 136-141. https://doi.org/10.1258/la.2011.011063Mira-Escolano M.P., Mendiola J., MĂ­nguez-AlarcĂłn L., Melgarejo M., Cutillas-TolĂ­n A., Roca M., LĂłpez-EspĂ­n J.J., Noguera-Velasco J.A., Torres-Cantero A.M. 2014. Longer anogenital distance is associated with higher testosterone levels in women: a cross-sectional study. BJOG, 121: 1359-1364. https://doi.org/10.1111/1471-0528.12627Mugnai C., Dal Bosco A., Castellini C. 2009. Effect of different rearing systems and pre-kindling handling on behaviour and performance of rabbit does. Appl. Anim. Behav. Sci., 118: 91-100. https://doi.org/10.1016/j.applanim.2009.02.007Nielsen S.S., Alvarez J., Bicout D.J., Calistri P., Depner K., Drewe J.A., Garin-bastuji B., Luis J., Rojas G., Michel V., Angel M., Chueca M., Roberts H.C., Sihvonen L.H., Spoolder H., Stahl K., Calvo A.V., Viltrop A., Buijs S., Edwards S., Candiani D., Mosbach-schulz O. 2020. Health and welfare of rabbits farmed in different production systems, EFSA J., 18: 1-96. https://doi.org/10.2903/j.efsa.2020.5944O'Malley B. 2005. Rabbits. In: O'Malley B. (Ed.), Clinical Anatomy and Physiology of Exotic Species. Elsevier, New York, pp. 173-195. https://doi.org/10.1016/B978-070202782-6.50011-9Palanza P., Parmigiani S., Vom Saal F.S. 1995. Urine marking and maternal aggression of wild female mice in relation to anogenital distance at birth. Physiol. Behav., 58: 827-835. https://doi.org/10.1016/0031-9384(95)00107-TPalka Y.S., Sawyer C.H. 1966. The effects of hypothalamic implants of ovarian steroids on oestrous behaviour in rabbits. J. Physiol., 185: 251-269. https://doi.org/10.1113/jphysiol.1966.sp007986R Core Team, 2019., A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/Rödel H.G., MonclĂșs R., von Holst D. 2006. Behavioral styles in European rabbits: Social interactions and responses to experimental stressors. Physiol. Behav., 89: 180-188. https://doi.org/10.1016/j.physbeh.2006.05.042Rödel H.G., Starkloff A., Bautista A., Friedrich A.C., Von Holst D. 2008. Infanticide and maternal offspring defence in European rabbits under natural breeding conditions. Ethology, 114: 22-31. https://doi.org/10.1111/j.1439-0310.2007.01447.xRommers J.M., Gunnink H., Klop A., De Jong I.C. 2011. Dynamics in aggressive behaviour of rabbit does in a group housing system: a descriptive study. In: 17th International Symposium on Housing and Diseases of Rabbits, Fur Providing Animals and Pet Animals, May 11-12. Celle, Germany, pp. 75-85.Rommers J.M., Reuvekamp B.J.F., Gunnink H., de Jong I.C. 2014. Effect of hiding places, straw and territory on aggression in group-housed rabbit does. Appl. Anim. Behav. Sci., 157: 117-126. https://doi.org/10.1016/j.applanim.2014.05.011Schönbrodt F.D., Perugini M. 2013. At what sample size do correlations stabilize? J. Res. Pers., 47: 609-612. https://doi.org/10.1016/j.jrp.2013.05.009Shargal D., Shore L., Roteri N., Terkel A., Zorovsky Y., Shemesh M., Steinberger Y. 2008. Fecal testosterone is elevated in high ranking female ibexes (Capra nubiana) and associated with increased aggression and a preponderance of male offspring. Theriogenology 69: 673-680. https://doi.org/10.1016/j.theriogenology.2007.11.017Simpson E.R. 2002. Aromatization of androgens in women: current concepts and findings. Fertil. Steril., 77: 6-10. https://doi.org/10.1016/S0015-0282(02)02984-9Squire L.R. 2009. Encyclopedia of Neuroscience, Volume 1. Academic Press. https://doi.org/10.1093/acprof:oso/9780195380101.003.0001Stadler A., Meiser C.K., Schaub G. a. 2011. "Living Syringes": use of Haematophagous Bugs as Blood Samplers from Small and Wild Animals. Nature Helps... 243-272. https://doi.org/10.1007/978-3-642-19382-8SzendrƑ Z., McNitt J.I., Matics Z., MikĂł A., GerencsĂ©r Z. 2016. Alternative and enriched housing systems for breeding does: A review. World Rabbit Sci., 24: 1-14. https://doi.org/10.4995/wrs.2016.3801Takahashi, Kayo, Hosoya T., Onoe K., Takashima T., Tanaka M., Ishii A., Nakatomi Y., Tazawa S., Takahashi, Kazuhiro, Doi H., Wada Y., Watanabe Y. 2018. Association between aromatase in human brains and personality traits. Sci. Rep., 8: 1-9. https://doi.org/10.1038/s41598-018-35065-4Theau-ClĂ©ment M., Poujardien B., Bellereaud J. 1990. Influence des traitements lumineux, modes de reproduction et Ă©tats physiologiques sur la productivitĂ© de lapines multipares. In: 5Ăšmes JournĂ©es de La Recherche Cunicole, Dec 1990, Paris, France.Thomsen R., Voigt C.C. 2006. Non-invasive blood sampling from primates using laboratory-bred blood-sucking bugs (Dipetalogaster maximus; Reduviidae, Heteroptera). Primates, 47: 397-400. https://doi.org/10.1007/s10329-006-0194-8Trainor B.C., Bird I.M., Marler C.A. 2004. Opposing hormonal mechanisms of aggression revealed through short-lived testosterone manipulations and multiple winning experiences. Horm. Behav., 45: 115-121. https://doi.org/10.1016/j.yhbeh.2003.09.006Trainor B.C., Kyomen H.H., Marler C.A. 2006. Estrogenic encounters: How interactions between aromatase and the environment modulate aggression. Front. Neuroendocrinol., 27: 170-179. https://doi.org/10.1016/j.yfrne.2005.11.001Ubilla E., Rebollar P.G. 1995. Influence of the postpartum day on plasma estradiol-17 ÎČ levels, sexual behaviour, and conception rate, in artificially inseminated lactating rabbits. Anim. Reprod. Sci., 38: 337-344. https://doi.org/10.1016/0378-4320(94)01366-TVoigt C.C., Von Helversen O., Michener R.H., Kunz T.H. 2003. Validation of a Non-Invasive Blood-Sampling Technique for Doubly-Labelled Water Experiments. J. Exp. Zool. A Comp. Exp. Biol., 296: 87-97. https://doi.org/10.1002/jez.a.10121Voigt C.C., Faßbender M., Dehnhard M., Wibbelt G., Jewgenow K., Hofer H., Schaub G.A. 2004. Validation of a minimally invasive blood-sampling technique for the analysis of hormones in domestic rabbits, Oryctolagus cuniculus (Lagomorpha). Gen. Comp. Endocrinol., 135: 100-107. https://doi.org/10.1016/j.ygcen.2003.08.005Voigt C.C., Peschel U., Wibbelt G., Frölich K. 2006. An Alternative, Less Invasive Blood Sample Collection Technique for Serologic Studies Utilizing Triatomine Bugs (Heteroptera; Insecta). J. Wildl. Dis., 42: 466-469. https://doi.org/10.7589/0090-3558-42.2.466von Engelhard N., Kappeler P.M., Heistermann M. 2000. Androgen levels and female social dominance in Lemur catta. In Proc.: R. Soc. Lond. B, 267: 1533-1539. https://doi.org/10.1098/rspb.2000.1175Vos A.C., MĂŒller T., Neubert L., Voigt C.C. 2010. Validation of a Less Invasive Blood Sampling Technique in Rabies Serology Using Reduviid Bugs (Triatominae, Hemiptera). J. Zoo. Wildl. Med., 41: 63-68. https://doi.org/10.1638/2009-0103.1Wingfield J.C., Hegner R.E., Dufty, Alfred M., Ball G.F. 1990. The "Challenge Hypothesis": Theoretical Implications for Patterns of Testosterone Secretion, Mating Systems, and Breeding Strategies. Am. Nat., 136: 829-846. https://doi.org/10.1086/285134Zomeño C., Birolo M., Zu A., Xiccato G., Trocino A. 2017. Aggressiveness in group-housed rabbit does: Influence of group size and pen characteristics. Appl. Anim. Behav. Sci., 194: 79-85. https://doi.org/10.1016/j.applanim.2017.05.016Zomeño C., Birolo M., Gratta F., Zuffellato A., Xiccato G., Trocino A. 2018. Effects of group housing system, pen floor type, and lactation management on performance and behaviour in rabbit does. Appl. Anim. Behav. Sci., 203: 55-63. https://doi.org/10.1016/j.applanim.2018.03.00

    Nutcrackers become choosy seed harvesters in a mast-crop year.

    Get PDF
    As an efficient seed-disperser, Eurasian nutcrackers (Nucifraga caryocatactes) generally consume and hoard mature, edible pine seeds for future use. In 2009, when the Arolla pine, Pinus. cembra, produced a mast-crop, we investigated cones discarded by nutcrackers. Most cones were only partly eaten and some mature seeds remained in the distal part. This was in contrast to years of lower seed production when nearly all seeds were harvested from the majority of cones. To determine whether nutcracker cone-discarding behaviour maximised intake rate, seed kernels and the aborted seeds rate were measured from the different cone parts. In 2009, seeds from cone-tops were on average 17% lighter than in the base and middle sections, and the proportion of aborted seeds in the top part was 81% higher than in the other sections. There was no difference in seed mass and proportion of aborted seeds in cone-tops of intact cones and cones handled by nutcrackers. Regarding each cone as a patch, cone discarding behaviour can be considered as an optimal cone-leaving rule, maximising rate of energy-intake, supporting the Marginal Value Theorem. Hence, we suggest that increased food abundance leads to more selective seed harvesting in nutcrackers
    • 

    corecore