6,502 research outputs found
Efficacy of essential oil of Piper aduncum against nymphs and adults of Diaphorina citri.
Insecticide application is the main way to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms, and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which was proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (65.2%, 76.6%, and 81.6%) at 0.5%, 0.75%, and 1.0% dilutions plus 0.025% adjuvant were tested. All treatments caused 90?100% mortality in nymphs. Topical treatments with oil containing 76.6% and 81.6% of dillapiol at 0.75% and 1% dilutions were effective (mortality less or equal 80%) in adults. However, the essential oil showed no residual activity against adults (mortality bigger or equal 30%). Because of its high efficacy against nymphs and adults, P. aduncum is a promising botanical insecticide for use in integrated pest management of D. citri
Efficacy of essential oil of Piper aduncum against nymphs and adults of Diaphorina citri.
Insecticide application is the mainway to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which has proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (69.3, 79.9 and 85.4%) at 0.5, 0.75 and 1.0% dilutions plus 0.025% adjuvant were tested
Características biológicas e parasitismo de Telenomus remus em ovos de Corcyra cephalonica, sob diferentes períodos de exposição ao parasitismo.
O objetivo deste trabalho foi avaliar as características biológicas e a porcentagem de parasitismo de T. remus em ovos do hospedeiro alternativo C. cephalonica, em diferentes períodos de exposição ao parasitismo, para selecionar o melhor método de criação do parasitoide neste hospedeiro. O experimento foi conduzido em sala climatizada (T: 25±2°C; UR: 70±10%; Fotofase: 12h), com delineamento inteiramente casualizado, sendo três tratamentos (períodos de exposição: 24, 48 e 72h) e 20 repetições. Em tubos de vidro de fundo chato, foram individualizadas fêmeas recém-emergidas (até 24h) de T. remus e alimentadas com mel. Aproximadamente 100 ovos inviabilizados de C. cephalonica foram colados com cola atóxica (30%) em cartelas de papel e oferecidos às fêmeas. O parasitismo foi permitido por diferentes períodos, de acordo com cada tratamento. Avaliou-se: porcentagem de parasitismo, duração do período ovo-adulto; viabilidade; razão sexual; e longevidade das fêmeas. Não houve diferença significativa entre os tratamentos avaliados, sendo que as variações verificadas entre o menor (24h) e o maior (72h) período de exposição ao parasitismo nos parâmetros avaliados foram: porcentagem de parasitismo (29,26% e 36,05%), período ovo-adulto (13,71 e 14 dias), viabilidade (80,76% e 74,86%), razão sexual (0,77 e 0,68 fêmeas) e longevidade (7,65 e 10,08 dias), respectivamente. Assim, estes resultados indicam que não é necessário um maior período de exposição ao parasitismo quando T. remus é criado em ovos do hospedeiro alternativo C. cephalonica. Ainda, estes resultados sugerem que a baixa porcentagem de parasitismo pode estar correlacionada com o comportamento pré-imaginal do inseto relacionado ao hospedeiro natural (Spodoptera frugiperda) onde é criado por sucessivas gerações, o que pode ser corroborado com a alta viabilidade verificada, sinalizando C. cephalonica como um hospedeiro alternativo em potencial
JUNO Conceptual Design Report
The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine
the neutrino mass hierarchy using an underground liquid scintillator detector.
It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants
in Guangdong, China. The experimental hall, spanning more than 50 meters, is
under a granite mountain of over 700 m overburden. Within six years of running,
the detection of reactor antineutrinos can resolve the neutrino mass hierarchy
at a confidence level of 3-4, and determine neutrino oscillation
parameters , , and to
an accuracy of better than 1%. The JUNO detector can be also used to study
terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard
Model. The central detector contains 20,000 tons liquid scintillator with an
acrylic sphere of 35 m in diameter. 17,000 508-mm diameter PMTs with high
quantum efficiency provide 75% optical coverage. The current choice of
the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO
as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of
detected photoelectrons per MeV is larger than 1,100 and the energy resolution
is expected to be 3% at 1 MeV. The calibration system is designed to deploy
multiple sources to cover the entire energy range of reactor antineutrinos, and
to achieve a full-volume position coverage inside the detector. The veto system
is used for muon detection, muon induced background study and reduction. It
consists of a Water Cherenkov detector and a Top Tracker system. The readout
system, the detector control system and the offline system insure efficient and
stable data acquisition and processing.Comment: 328 pages, 211 figure
Construction and On-site Performance of the LHAASO WFCTA Camera
The focal plane camera is the core component of the Wide Field-of-view
Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air
Shower Observatory (LHAASO). Because of the capability of working under
moonlight without aging, silicon photomultipliers (SiPM) have been proven to be
not only an alternative but also an improvement to conventional photomultiplier
tubes (PMT) in this application. Eighteen SiPM-based cameras with square light
funnels have been built for WFCTA. The telescopes have collected more than 100
million cosmic ray events and preliminary results indicate that these cameras
are capable of working under moonlight. The characteristics of the light
funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate,
assembly techniques). In this paper, we present the design features,
manufacturing techniques and performances of these cameras. Finally, the test
facilities, the test methods and results of SiPMs in the cameras are reported
here.Comment: 45 pages, 21 figures, articl
Does or did the supernova remnant Cassiopeia A operate as a PeVatron?
For decades, supernova remnants (SNRs) have been considered the prime sources
of Galactic Cosmic rays (CRs). But whether SNRs can accelerate CR protons to
PeV energies and thus dominate CR flux up to the knee is currently under
intensive theoretical and phenomenological debate. The direct test of the
ability of SNRs to operate as CR PeVatrons can be provided by ultrahigh-energy
(UHE; ~TeV) -rays. In this context, the historical
SNR Cassiopeia A (Cas A) is considered one of the most promising target for UHE
observations. This paper presents the observation of Cas A and its vicinity by
the LHAASO KM2A detector. The exceptional sensitivity of LHAASO KM2A in the UHE
band, combined with the young age of Cas A, enabled us to derive stringent
model-independent limits on the energy budget of UHE protons and nuclei
accelerated by Cas A at any epoch after the explosion. The results challenge
the prevailing paradigm that Cas A-type SNRs are major suppliers of PeV CRs in
the Milky Way.Comment: 11 pages, 3 figures, Accepted by the APJ
Activated Human CD4+CD45RO+ Memory T-Cells Indirectly Inhibit NLRP3 Inflammasome Activation through Downregulation of P2X7R Signalling
Inflammasomes are multi-protein complexes that control the production of pro-inflammatory cytokines such as IL-1β. Inflammasomes play an important role in the control of immunity to tumors and infections, and also in autoimmune diseases, but the mechanisms controlling the activation of human inflammasomes are largely unknown. We found that human activated CD4+CD45RO+ memory T-cells specifically suppress P2X7R-mediated NLRP3 inflammasome activation, without affecting P2X7R-independent NLRP3 or NLRP1 inflammasome activation. The concomitant increase in pro-IL-1β production induced by activated memory T-cells concealed this effect. Priming with IFNβ decreased pro-IL-1β production in addition to NLRP3 inflammasome inhibition and thus unmasked the inhibitory effect on NLRP3 inflammasome activation. IFNβ suppresses NLRP3 inflammasome activation through an indirect mechanism involving decreased P2X7R signaling. The inhibition of pro-IL-1β production and suppression of NLRP3 inflammasome activation by IFNβ-primed human CD4+CD45RO+ memory T-cells is partly mediated by soluble FasL and is associated with down-regulated P2X7R mRNA expression and reduced response to ATP in monocytes. CD4+CD45RO+ memory T-cells from multiple sclerosis (MS) patients showed a reduced ability to suppress NLRP3 inflammasome activation, however their suppressive ability was recovered following in vivo treatment with IFNβ. Thus, our data demonstrate that human P2X7R-mediated NLRP3 inflammasome activation is regulated by activated CD4+CD45RO+ memory T cells, and provide new information on the mechanisms mediating the therapeutic effects of IFNβ in MS
Measurement of ultra-high-energy diffuse gamma-ray emission of the Galactic plane from 10 TeV to 1 PeV with LHAASO-KM2A
The diffuse Galactic -ray emission, mainly produced via interactions
between cosmic rays and the interstellar medium and/or radiation field, is a
very important probe of the distribution, propagation, and interaction of
cosmic rays in the Milky Way. In this work we report the measurements of
diffuse -rays from the Galactic plane between 10 TeV and 1 PeV
energies, with the square kilometer array of the Large High Altitude Air Shower
Observatory (LHAASO). Diffuse emissions from the inner
(, ) and outer
(, ) Galactic plane are detected with
and significance, respectively. The outer Galactic
plane diffuse emission is detected for the first time in the very- to
ultra-high-energy domain (~TeV). The energy spectrum in the inner Galaxy
regions can be described by a power-law function with an index of
, which is different from the curved spectrum as expected from
hadronic interactions between locally measured cosmic rays and the
line-of-sight integrated gas content. Furthermore, the measured flux is higher
by a factor of than the prediction. A similar spectrum with an index of
is found in the outer Galaxy region, and the absolute flux for
TeV is again higher than the prediction for hadronic
cosmic ray interactions. The latitude distributions of the diffuse emission are
consistent with the gas distribution, while the longitude distributions show
clear deviation from the gas distribution. The LHAASO measurements imply that
either additional emission sources exist or cosmic ray intensities have spatial
variations.Comment: 12 pages, 8 figures, 5 tables; accepted for publication in Physical
Review Letters; source mask file provided as ancillary fil
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