904 research outputs found
Trichothecenes NIV and DON modulate the maturation of murinedendritic cells
Nivalenol (NIV) and Deoxynivalenol (DON), mycotoxins of the trichothecene family are considered very common food contaminants. In this work, we investigated whether the immunotoxic effects ascribed to these trichothecenes may be mediated by perturbations in the activity of dendritic cells (DCs). Murine bone marrow-derived DCs were used to evaluate the effects of NIV and DON on the LPS-induced maturation process.We found that the expression of the class II MHC and of the accessory CD11c molecules, but not of the costimulatory CD86 marker, was down-regulated by NIV and DON exposure in LPS-treated DCs, as well as nitric oxide (NO) production. Interestingly, NIV, but not DON, induced DC necrosis. Moreover, the analysis of the cytokine pattern showed that IL-12 and IL-10 expressions induced by LPS exposure were suppressed by both trichothecenes in a dose-dependent fashion. On the other hand, the secretion of the proinflammatory cytokine TNFa was increased as a direct consequence of DON and NIV exposure. Taken together, our data indicated that the immunotoxicity of NIV and DON was related to the capacity of both trichothecenes to interfere with phenotypic and functional features of maturing DCs
Mycotoxins nivalenol and deoxynivalenol differently modulate cytokine mRNA expression in Jurkat T cells.
Deoxynivalenol (DON) and its hydroxylated form nivalenol (NIV) are Fusarium mycotoxins that occur in cereal grains alone or in
combination. Several studies have shown that these metabolites affect lymphocyte functions. However, the molecular mechanisms
underlying their activities are still partially known. To address this issue, we examined the influence of NIV and DON in modulating
IFNc, IL-2 and IL-8 mRNA levels in Jurkat T cells. In PMA/ionomycin stimulated cells, pre-incubated with increasing concentrations of NIV, transcription was induced in the range 0.06–2 lM; higher concentrations of NIV were found non-stimulating (4 lM) or inhibitory (8 lM) for IFNc and IL-2 whereas IL-8 was still induced. DON administration elicited a similar profile for IL-8 and IFNc, whilst IL-2 mRNA was induced in a broader range of concentrations. Combination of NIV and DON at 1:1 and 1:10 ratios essentially restored the cytokine transcriptional pattern observed with NIV alone but the level of transcripts, with the exception of IL-8, peaked at lower concentrations suggesting interactive effects. Moreover both mycotoxins caused inhibition of cell proliferation, mediated by induction of apoptosis, confirming previous results and highlighting the usefulness of Jurkat as a T-cell model to study the effects of mycotoxins on the immune functions in humans
Gigabit Satellite Network for NASA\u27s Advanced Communication Technology Satellite (ACTS): Features, Capabilities, and Operations
This paper describes the Gigabit Satellite Network (GSN) being developed under joint sponsorship of NASA and ARPA. The system will use the wide-band Satellite Switched Time Division Multiple Access (SS-TDMA) capability and hopping beam antennas of NASA\u27s Advanced Communications Technology Satellite (ACTS). The GSN network will provide full-duplex SONET services over satellite at OC-3 (155.54 Mb/s) and OC-12 (622.078 Mb/s) rates. Typical applications will include connection of distributed SONET/ATM fiber islands over satellite, wide-area distributed supercomputer networking, high-definition digital TV, and high-speed file transfer.
The RF link consists of 30 GHz uplink and 20 GHz downlink signals transmitted using a 3.4 meter offset-fed antenna and 120 Watt helix-type TWTA. The burst modem uses offset QPSK or offset-BPSK modulations for transmission at 696 Mb/s and 348 Mb/s, respectively. Transmissions to the satellite are protected using Reed-Solomon encoding, providing almost error-free clear-sky performance and, in the case of rain-fade, bit error rates better than 1099% of the time.
The terrestrial side of the ground station will function as standard SONET Line Terminating Equipment (LTE), with OC-3 and OC-12 fiber interfaces, and is capable of multiplexing and demultiplexing the SONET signals down to the STS-1 (51.84 Mb/s) level. These STS-1 signals can be routed independently through the satellite between various ground stations.
Management of the network is performed using a Network Management Terminal (NMT) and is based on standard SNMP and Internet protocols. The earth stations can also be remotely monitored and controlled via the satellite channel or via the terrestrial Internet
CT-based tumour response criteria compared after combined treatment for liver metastases of colorectal cancer
open6noPurpose: The aim of this analysis is to compare different tumour response
criteria (TRC) after chemotherapy combined with bevacizumab in liver
metastases from colorectal cancer (mCRC) to ascertain the best early
prognostic indicator of response.
Methods and Materials: 103 target liver metastases from 65 mCRC patients
treated with chemoterapy plus bevacizumab were examined at the Istituto
Oncologico Veneto IOV-IRCSS (March 2008-January 2013). All patients had
baseline CT and at least one follow-up scan. Tumour response was
retrospectively analyzed by two radiologists using RECIST1.1, modified Choi,
and Chun morphologic criteria. Tumour response, classified as good (complete
or partial response) or poor (stable or progressive disease), was compared
with progression-free survival (PFS) at first follow-up (t1) and time of best
response. Interobserver agreement and concordance between TRC were
measured.
Results: At t1, 32.31% showed a good response according to RECIST1.1
(median PFS 11.1), 84.62% according to Choi (median PFS 10.8). These
percentages rose to 49.23% (median PFS 12.1) and 87.69% (median PFS
10.8), respectively, at the time of best response. According to Chun, 67.69%
showed a good response at the time of best response (median PFS 10.8). The
Choi criteria detected a higher proportion of good responders at t1, showing a
better correlation with PFS; all methods correlated with PFS at the time of best
response.
Conclusion: The Choi criteria proved more consistent in the early detection of
response in mCRC treated with chemotherapy plus bevacizumab,
underscoring the importance of using these criteria in the early assessment of
response to combined treatment.openopenVarotto, A.; Di Grazia, L.; Aliberti, C.; Bergamo, F.; Nardin, M.; Pomerri, F.Varotto, A.; Di Grazia, L.; Aliberti, C.; Bergamo, F.; Nardin, M.; Pomerri, Fabi
Phase Coupling in Langmuir Wave Packets: Evidence for Four Wave Interactions in Solar Type III Radio Bursts
The four wave interaction process, known as the oscillating two stream instability (OTSI) is considered as one of the mechanisms responsible for stabilizing the electron beams associated with solar type III radio bursts. It has been reported that (1) an intense localized Langmuir wave packet associated with a type III burst contains the spectral characteristics of the OTSI: (a) a resonant peak at the local electron plasma frequency, f(sub pe), (b) a Stokes peak at a frequency slightly lower than f(sub pe), (c) anti-Stokes peak at a frequency slightly higher than f(sub pe), and (d) a low frequency enhancement below a few hundred Hz, (2) the frequencies and wave numbers of these spectral components satisfy the resonance conditions of the OTSI, and (3) the peak intensity of the wave packet is well above the thresholds for the OTSI as well as spatial collapse of envelope solitons. Here, for the first time, applying the trispectral analysis on this wave packet, we show that the tricoherence, which measures the degree of coherent four-wave coupling amongst the observed spectral components exhibits a peak. This provides an additional evidence for the OTSI and related spatial collapse of Langmuir envelope solitons in type III burst sources
SEISMIC CHARACTERIZATION OF SHALLOW BEDROCK SITES WITH MULTIMODAL MONTECARLO INVERSION OF SURFACE WAVEDATA
Direct radiative effects by anthropogenic particles at a polluted site: Rome (Italy)
The direct radiative effect (DRE) by all (anthropogenic plus natural) and anthropogenic aerosols is calculated at the solar (0.3–4 μm) and infrared (4–200 μm) spectral range to better address the annual cycle of the anthropogenic
aerosol impact at a site (Rome, Italy) significantly affected by pollution. Aerosol optical and microphysical properties from 2003 AERONET Sun/sky-photometer
measurements and solar surface albedos based on MODIS satellite sensor data constitute the necessary input to radiative transfer simulations. Clear- and all-sky
conditions are investigated by adopting ISCCP monthly products for high-, mid-, and low-cloud cover. It is shown that monthly mean values of aerosol optical depths by anthropogenic particles (AODa) are on average more than 50% of the corresponding all-aerosol-optical-depth (AOD) monthly means. In particular, the AODa/AOD ratio that varies within the (0.51–0.83) on autumn-winter (AW,
October-March), varies within the (0.50–0.71) range on spring-summer (SS, April-September) as a consequence of the larger contribution of natural particles on SS. The surface (sfc), all-sky DRE by anthropogenic particles that is negative all year round at solar wavelengths, represents on average 60% and 51% of the all-sky sfc-DRE by all aerosols
on AW and SS, respectively. The all-sky atmospheric forcing by anthropogenic particles (AFa) that is positive all year round, is little dependent on seasons: it varies within the (1.0–4.1)W/m2 and (2.0–4.2)W/m2 range on AW and SS, respectively. Conversely, the all-sky AF by all aerosols is characterized by a marked seasonality. As a consequence, the atmospheric forcing by anthropogenic particles that on average is 50% of the AF value on AW, decreases down to 36% of the AF value on SS. Infrared aerosol DREs that are positive all year round are significantly smaller than the corresponding absolute values of solar DREs. Clouds decrease on average ToA- and sfc-DRE absolute values by anthropogenic particles of 36% and 23%, respectively and are quite responsible of the seasonal dependence of aerosol forcing efficiencies by all and anthropogenic aerosols
Seismic characterization of shallow bedrock sites with multi-modal Monte Carlo inversion of surface wave data
Phase Coupling Between Spectral Components of Collapsing Langmuir Solitons in Solar Type III Radio Bursts
We present the high time resolution observations of one of the Langmuir wave packets obtained in the source region of a solar type III radio burst. This wave packet satisfies the threshold condition of the supersonic modulational instability, as well as the criterion of a collapsing Langmuir soliton, i.e., the spatial scale derived from its peak intensity is less than that derived from its short time scale. The spectrum of t his wave packet contains an intense spectral peak at local electron plasma frequency, f(sub pe) and relatively weaker peaks at 2f(sub pe) and 3f(sub pe). We apply the wavelet based bispectral analysis technique on this wave packet and compute the bicoherence between its spectral components. It is found that the bicoherence exhibits two peaks at (approximately f(sub pe), approximately f(sub pe)) and (approximately f(sub pe) approximately 2f(sub pe)), which strongly suggest that the spectral peak at 2f(sub pe) probably corresponds to the second harmonic radio emission, generated as a result of the merging of antiparallel propagating Langmuir waves trapped in the collapsing Langmuir soliton, and, the spectral peak at 3f(sub pe) probably corresponds to the third harmonic radio emission, generated as a result of merging of a trapped Langmuir wave and a second harmonic electromagnetic wave
Herança da resistência de variedades comerciais brasileiras de soja à podridão radicular de fitóftora.
O objetivo do estudo foi avaliar a herança da resistência à podridão radicular de fitóftora, causada por causada por Phytophthora sojae (Kaufm. & Gerd.), presentes em variedades comerciais resistentes BRS 260, BRS 262, BRS 246RR e BRSMG 752S. Até hoje 14 genes, denominados Rps, foram descritos por conferirem resistência à PRF, os quais tem sido amplamente utilizados nos programas de melhoramento para proteção das cultivares de soja. O material experimental foi desenvolvido a partir do cruzamento das quatro cultivares entre si, totalizando seis cruzamentos. A população F2, os parentais utilizados nos cruzamentos e a cultivar suscetÃvel BRS 268, foram inoculados com o patógeno utilizando a metodologia de Keeling (1982), adaptada por Yorinori (1996). O teste do qui-quadrado (?2) foi aplicado para aceitar ou rejeitar os padrões de segregação encontrados de plantas mortas e não-mortas esperadas para a população F2 segundo padrões mendelianos. O cruzamento BRS 260 x BRS 246RR não resultou em nenhum indivÃduo morto, com isso conclui-se que os mesmos contém um gene de resistência no mesmo loco conferindo resistência a P. sojae. Nos cruzamentos BRSMG 752S x BRS 260 e BRS 246RR x BRSMG 752S foram observados padrões de segregação semelhantes, correspondentes à segregação de dois genes dominantes independentes. As três combinações de cruzamentos envolvendo a cultivar BRS 262 indicam a presença de três genes segregando independentemente nesses cruzamentos. Pode-se concluir que apenas nesse grupo de quatro cultivares resistentes já existem quatro locos de resistência à P. sojae disponÃveis para serem explorados em programas de melhoramento de soja
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