Size of predatory mites and refuge entrance determine success of biological control of the coconut mite

Published online: 06 July 2016Predators face the challenge of accessing prey that live in sheltered habitats. The coconut mite Aceriaguerreronis Keifer (Acari: Eriophyidae) lives hidden beneath the perianth, which is appressed to the coconut fruit surface, where they feed on the meristematic tissue. Its natural enemy, the predatory mite Neoseiuluspaspalivorus De Leon (Acari: Phytoseiidae), is larger than this pest and is believed to gain access to the refuge only after its opening has increased with coconut fruit age. In the field, experimentally enlarging the perianth-rim-fruit distance beyond the size of the predators resulted in earlier predator occurrence beneath the perianth and lower numbers of coconut mites. On non-manipulated coconut fruits, the predators gained access to the prey weeks later than on manipulated ones, resulting in higher pest densities of coconut mites. Successful biological control thus critically hinges on the size of the predator relative to the opening of the prey refuge

A comparative study of lesions caused by different parasitic stages of Boophilus Microplus (Canestrini) in the skins of naturally infested taurine and zebuine hosts. The correlation of tick resistence with mast cell counts in the host's skin

Biópsias de pele lesada por larvas, ninfas e fêmeas engurgitadas de Boophilus microplus foram colhidas de cinco Bos taurus da raça Holandesa e de cinco Bos indicus da raça Gir, adquiridos na mesma propriedade, com aproximadamente 23 meses de idade, e colocados em convivência no mesmo pasto durante 90 dias que precederam este ensaio. O grau de susceptibilidade ao ácaro foi estimado previamente, sendo os zebuínos cerca de 15 vezes mais resistentes que os taurinos. As biópsias foram colhidas de modo que o parasito ficasse localizado no centro do fragmento de pele. Essas peças foram fixadas em formalina a 10% durante 24 h e processadas pelos métodos usuais em histologia seguindo-se a coloração pela técnica da Hematoxilin-Eosin ou do “tricrômico” de Masson. Não foram constatadas diferenças morfológicas que pudessem ser relacionadas aos diferentes graus de resistência ao parasito entre os taurinos e zebuinos. Biópsias foram colhidas de zonas não lesadas, na região da virilha dos cinco taurinos e dos cinco zebuínos, fixadas em subacetato de chumbo a 1% em solução de etanol 50%, contendo 1% de ácido acético, por 24 h. A seguir os fragmentos foram processados pelas técnicas usuais em histologia e corados pelo método do azul de toluidina 0,1%. Os mastócitos foram contados comparativamente em 80 campos microscópicos, em aumento de 100 vezes. Os resultados mostram que os zebuínos tem mais que o dobro do número de mastócitos dérmicos quando comparado com o encontrado nos taurinos. Esses resultados sugerem que os mastócitos dérmicos possam, pelo menos em parte, participar dos mecanismos de resistência dos bovinos ao Boophilus microplus.Biopsies of skin injuries caused by larvae, nymphs, unengorged and engorged females of Boophilus microplus were collected from five Bos taurus and five Bos indicus steers, which had been bom on the same ranch, aged about 23 months and had been grazing together in the same pasture during the preceding 90 days. Their susceptibilities to the tick had been previously estimated, being the taurine animals around fifteen times as susceptible as the zebuine ones. The biopsies were made in such a manner that the mouth pieces were in the center of the skin fragments. These were immersed for 24 hours in 10% formalin, then processed through usual histopathological techniques and stained either by the haematoxilin-eosin or by Masson’s “trichromic” procedures. No morphological differences were found capable of explaining the higher tick susceptibility observed for the taurine hosts as compared to the zebuine’s. Biopsies from non parasitized skin from the groin region of five B. taurus and five B. indicus steers were fixed in 1% lead subacetate, plus 50% ethanol, plus 1% acetic acid, for 24 hours, which they were histologically processed and stained in 0.1 % toluidin blue. The mast cells were comparatively counted in 80 microscope fields per sample with 100 diameters of magnification and the counts averaged more than twice as high in the zebuine than in the taurine host’s skins. These results strongly suggest that mast cells participate as important elements in the bovine host’s resistance to the cattle tick

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Inclusive search for same-sign dilepton signatures in pp collisions at root s=7 TeV with the ATLAS detector

An inclusive search is presented for new physics in events with two isolated leptons (e or mu) having the same electric charge. The data are selected from events collected from p p collisions at root s = 7 TeV by the ATLAS detector and correspond to an integrated luminosity of 34 pb(-1). The spectra in dilepton invariant mass, missing transverse momentum and jet multiplicity are presented and compared to Standard Model predictions. In this event sample, no evidence is found for contributions beyond those of the Standard Model. Limits are set on the cross-section in a fiducial region for new sources of same-sign high-mass dilepton events in the ee, e mu and mu mu channels. Four models predicting same-sign dilepton signals are constrained: two descriptions of Majorana neutrinos, a cascade topology similar to supersymmetry or universal extra dimensions, and fourth generation d-type quarks. Assuming a new physics scale of 1 TeV, Majorana neutrinos produced by an effective operator V with masses below 460 GeV are excluded at 95% confidence level. A lower limit of 290 GeV is set at 95% confidence level on the mass of fourth generation d-type quarks

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurement of inclusive two-particle angular correlations in pp collisions with the ATLAS detector at the LHC

We present a measurement of two-particle angular correlations in proton- proton collisions at s√=900 GeV and 7 TeV. The collision events were collected during 2009 and 2010 with the ATLAS detector at the Large Hadron Collider using a single-arm minimum bias trigger. Correlations are measured for charged particles produced in the kinematic range of transverse momentum p T  > 100 MeV and pseudorapidity |η| < 2.5. A complex structure in pseudorapidity and azimuth is observed at both collision energies. Results are compared to pythia 8 and herwig++ as well as to the AMBT2B, DW and Perugia 2011 tunes of pythia 6. The data are not satisfactorily described by any of these models

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Search for charginos in e+e- interactions at sqrt(s) = 189 GeV

An update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure

EFICÁCIA DE DOIS SISTEMAS DE TRATAMENTO ANTI-HELMÍNTICO EM FILHOTES DE CÃES COM INFECÇÃO NATURAL

O objetivo do presente trabalho foi testar dois esquemas de tratamento para o combate da parasitose gastrintestinal em filhotes de cães recém-desmamados. Foram estabelecidos dois grupos de tratamento, ambos tratados com uma suspensão pamoato de pirantel e oxantel: grupo 1 - quatro desverminações com intervalos de 15 dias e grupo 2 -três desverminações, nos dias 0, 5 e 25 pós desmame. O primeiro tratamento apresentou redução de 98,2 % no número de ovos por grama de fezes (opg) de Toxocara canis, após a primeira desverminação. Cem por cento de redução de opg foi obtido após o segundo tratamento. No tratamento 2, foi obtido um resultado semelhante após três tratamentos. Para ovos de Ancylostoma sp. a formulação mostrou eficácia após a primeira dose para ambos os tratamentos preconizados. Estes resultados indicam que os esquemas de tratamento propostos poderiam ser adotados para combate das infecções por estes parasitas em animais recém-desmamados. Comparison of the efficacy of two systems of antihelminthic treatment in puppies with natural infection Abstract This work was developed to test two treatment outlines for gastrointestinal parasitosis control in weaned puppies. Two treatment groups were established, both treated with oxantel and pyrantel pamoate suspension: group 1 (four doses with 15-days intervals) and group 2 (three doses, at zero, 5th and 25th days). The first treatment presented reduction of 98.2 % on the number of eggs of Toxocara canis per gram of feces (epg) after the first dose. Complete epg reduction was observed after the second treatment, 15 days later. Similar result was obtained after the third dose for the treatment 2. Both treatment protocols showed effectiveness for eggs of Ancylostoma sp. after the first dose. These results indicate that both treatment outlines could be applied for the roundworm and the hookworm control in recently-weaned puppies