936 research outputs found
Ant Mimicry by an Aphid Parasitoid, Lysiphlebus fabarum
In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4–6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation
Design and Fabrication of Birdcage Resonators for Low-pressure Plasma Excitation
This paper presents a design, analysis and optimization of birdcage resonators employed in a novel radiofrequency plasma source. Three resonators were simulated and fabricated. The resonators differ in their design and in the different materials of used dielectric – polyimide and polytetrafluorethylene (PTFE). The resonance frequency of fabricated samples possesses a maximal error of 2.2 % compared to the simulated values. The performance in plasma excitation is related to the electrical parameters, while the best performing resonator (PTFE-based) exhibits the maximum real impedance of 644.3 Ω at the resonance frequency and the 799.5 V/m electric field strength. This resonator shows the best power efficiency in a plasma ignition experiment. The resonator ignited the discharge at ca. 1 Pa of ambient air atmosphere with only 0.34 W of input radiofrequency power
The InBIO barcoding initiative database: DNA barcodes of portuguese Diptera 02 - Limoniidae, Pediciidae and Tipulidae
Data PaperBackground
The InBIO Barcoding Initiative (IBI) Diptera 02 dataset contains records of 412 crane fly
specimens belonging to the Diptera families: Limoniidae, Pediciidae and Tipulidae. This
dataset is the second release by IBI on Diptera and it greatly increases the knowledge on
the DNA barcodes and distribution of crane flies from Portugal. All specimens were
collected in Portugal, including six specimens from the Azores and Madeira archipelagos.
Sampling took place from 2003 to 2019. Specimens have been morphologically identified
to species level by taxonomists and belong to 83 species in total. The species, represented
in this dataset, correspond to about 55% of all the crane fly species known from Portugal
and 22% of crane fly species known from the Iberian Peninsula. All DNA extractions and most specimens are deposited in the IBI collection at CIBIO, Research Center in
Biodiversity and Genetic Resourcesinfo:eu-repo/semantics/publishedVersio
A STUDY OF PRAON HALIDAY (HYMENOPTERA: BRACONIDAE: APHIDIINAE) IN SOUTH-EAST IRAN WITH TWO NEW RECORDS
Aphid parasitoids belonging to Praon Haliday in Kerman Province (South-East Iran) were studied. Parasitoid species were reared from field-collected aphids, and the tritrophic associations of parasitoids, their aphid hosts, and the respective host plants were identified. In total, 18 tritrophic associations were presented, from which seven host aphids, eight host plants and six host aphid-host plant combinations were new for Iran. Two species, P. flavinode (Haliday, 1833) and P. unitum Mescheloff & Rosen, 1988, were recorded for the first time from Iran. An illustrated key together with supplementary figures for the identification of species is provided
Both XPA and DNA polymerase eta are necessary for the repair of doxorubicin-induced DNA lesions
Doxorubicin (DOX) is an important tumor chemotherapeutic agent, acting mainly by genotoxic action. This work focus on cell processes that help cell survival, after DOX-induced DNA damage. in fact, cells deficient for XPA or DNA polymerase eta (pol eta, XPV) proteins (involved in distinct DNA repair pathways) are highly DOX-sensitive. Moreover, LY294002, an inhibitor of PIKK kinases, showed a synergistic killing effect in cells deficient in these proteins, with a strong induction of G2/M cell cycle arrest. Taken together, these results indicate that XPA and pol eta proteins participate in cell resistance to DOX-treatment, and kinase inhibitors can selectively enhance its killing effects, probably reducing the cell ability to recover from breaks induced in DNA. (C) 2011 Elsevier Ireland Ltd. All rights reserved.Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)USP-COFECUB (SĂŁo Paulo, Brazil)Univ SĂŁo Paulo, Dept Microbiol, Inst Biomed Sci, SĂŁo Paulo, BrazilUniv Paris Sud, Inst Gustave Roussy, Ctr Natl Rech Sci, UMR8200, Villejuif, FranceFed Univ SĂŁo Paulo UNIFESP, Dept Biol Sci, Diadema, SP, BrazilUniv Fed Rio Grande do Sul, Ctr Biotechnol, Dept Biophys, Porto Alegre, RS, BrazilFed Univ Hlth Sci Porto Alegre UFCSPA, Dept Basic Hlth Sci, Porto Alegre, RS, BrazilFed Univ SĂŁo Paulo UNIFESP, Dept Biol Sci, Diadema, SP, BrazilWeb of Scienc
Treatment dilemmas in asymptomatic children with primary hemophagocytic lymphohistiocytosis
Asymptomatic carriers (ACs) of pathogenic biallelic mutations in causative genes for primary hemophagocytic lymphohistiocytosis (HLH) are at high risk of developing life-threatening HLH, which requires allogeneic hematopoietic stem cell transplantation (HSCT) to be cured. There are no guidelines on the management of these asymptomatic patients. We analyzed the outcomes of pairs of index cases (ICs) and subsequently diagnosed asymptomatic family members carrying the same genetic defect. We collected data from 22 HSCT centers worldwide. Sixty-four children were evaluable. ICs presented with HLH at a median age of 16 months. Seven of 32 ICs died during first-line therapy, and 2 are alive after chemotherapy only. In all, 23/32 underwent HSCT, and 16 of them are alive. At a median follow-up of 36 months from diagnosis, 18/32 ICs are alive. Median age of ACs at diagnosis was 5 months. Ten of 32 ACs activated HLH while being observed, and all underwent HSCT: 6/10 are alive and in complete remission (CR). 22/32 ACs remained asymptomatic, and 6/22 have received no treatment and are in CR at a median follow-up of 39 months. Sixteen of 22 underwent preemptive HSCT: 15/16 are alive and in CR. Eight-year probability of overall survival (pOS) in ACs who did not have activated HLH was significantly higher than that in ICs (95% vs 45%; P = .02), and pOS in ACs receiving HSCT before disease activation was significantly higher than in ACs receiving HSCT after HLH activation (93% vs 64%; P = .03). Preemptive HSCT in ACs proved to be safe and should be considered
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