We have shown previously that dendritic cells (DC) produce IL-12 upon interaction with CD4+ T cells. Here we ask how this IL-12 production is induced and regulated. Quantitative PCR and in situ ...hybridization for IL-12 p40 and an ELISA specific for the p70 heterodimer were used to determine IL-12 production. We demonstrate that ligation of either CD40 or MHC class II molecules independently trigger IL-12 production in DC, and that IL-12 production is downregulated by IL-4 and IL-10. The levels of bioactive IL-12 that can be released by triggering with an anti-CD40 mAb or with a T cell hybridoma are high (range 260-4700 pg/ml from 1 X 10(6) DC in 72 h). The CD40-mediated pathway indicates that IL-12 production is induced in DC upon interaction with activated, CD40 ligand-expressing helper T cells, even in the absence of cognate antigen recognition. Side-by-side comparison of IL-12 production, and blocking experiments employing an anti-CD40 ligand mAb, suggest that the CD40-mediated pathway is quantitatively more significant than induction via the MHC class II molecule. The importance of the CD40/CD40 ligand interaction for IL-12 induction in DC likely contributes to the recent finding that mice lacking the CD40 ligand are impaired in mounting Th1 type cell-mediated immune responses.
Precise data on the neutron magnetic form factor Gmn have been obtained with measurements of the ratio of cross sections of D(e,e′n) and D(e,e′p) up to momentum transfers of Q2=0.9 (GeV/c)2. Data ...with typical uncertainties of 1.5% are presented. These data allow for the first time to extract a precise value of the magnetic radius of the neutron.
Sustainable production in the Everglades Agricultural Area (EAA) is confounded by decreasing soil depth and high annual rainfall. Formerly a sawgrass marsh, Histosols predominate much of the EAA and ...these soils have frequently flooded following their drainage in the early 20th century. Subsidence has increased inundation frequency as soil depth has decreased to less than 25 cm in many locations. A 2-year lysimeter study was conducted to examine alternative management practices for improved agricultural sustainability given frequent flooding and reduced oxidation rates on Histosols. Specific management factors examined included water-table, soil depth, and nitrogen (N) fertilizer effects on sugarcane leaf nutrient concentrations and soil nutrient cycling. The trial utilized soil depths of 13 and 25 cm, water tables of constant and periodically flooded, and N fertilizer rates of 0 and 168 kg ha
−1
year
−1
. Periodic flooding increased plant uptake of manganese (Mn), silicon (Si), and boron (B). Yield increases associated with additional N indicate a potential need to develop fertilizer rate recommendations for shallow Histosols. Soil depth impacted sugarcane nutrient uptake with 25 cm of soil depth significantly affecting examined leaf nutrient concentrations except iron (Fe). Sugarcane yield may benefit if additional N and potassium (K) are added at rates specific to soil depth. Proximity to bedrock led to excessive calcium (Ca) uptake and low K and Fe DRIS (Diagnosis and Recommendation Integrated System) values were below recommendations. Data from this study can assist development of precision agricultural practices in the EAA that utilize soil depth.
The three-spectrometer facility at the Mainz microtron MAMI Blomqvist, K.I; Boeglin, W.U; Böhm, R ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/1998, Letnik:
403, Številka:
2
Journal Article
Recenzirano
A set-up of three high-resolution magnetic spectrometers, for simplicity named A, B and C, has been built as the central facility for the precise determination of double and triple coincidence cross ...sections of hadron knock-out and meson production through the scattering of electrons at the Mainz microtron MAMI. The spectrometers A and C with point-to-point optics in the dispersive plane and parallel-to-point optics in the non-dispersive plane have a solid angle of 28 msr and a momentum acceptance of 20 and 25%, respectively. They each consist of a quadrupole, a sextupole and two dipole magnets, reaching maximum momenta of 735 and 550 MeV/c, respectively. The spectrometer B has a solid angle of 5.6 msr and a somewhat reduced momentum acceptance of 15%, but it reaches a maximum momentum larger than that of the MAMI electron beam (855 MeV/c). It consists of a single-clamshell dipole magnet with point-to-point optics in both planes. Each spectrometer is equipped with a position-sensitive detector system consisting of four planes of vertical drift chambers, two planes of plastic scintillators and a threshold gas Cherenkov detector. The operational experiences demonstrate that all three spectrometers exceed the specifications. Selected results of double (e, e′
x) and triple (e, e′
x
1
x
2) coincidence experiments,
x
1 and
x
2 standing for charged hadrons, are presented, which demonstrate the performance of the whole set-up.
The recoil proton polarization has been measured in the p(e-->,e'p-->)pi(0) reaction in parallel kinematics around W = 1232 MeV, Q2 = 0.121 (GeV/c)2, and epsilon = 0.718 using the polarized cw ...electron beam of the Mainz Microtron. All three proton polarization components, Px/P(e) = (-11.4+/-1.3+/-1.4)%, P(y) = (-43.1+/-1.3+/-2.2)%, and P(z)/P(e) = (56.2+/-1.5+/-2.6)%, could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio, CMR = (-6.4+/-0.7(stat)+/-0.8(syst))%, was determined from Px in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal-to-transverse response is discussed.
This paper describes a 352 element detector, designed for the focal plane of the 855 MeV electron spectrometer at the Institut für Kernphysik in Mainz. The system tags bremsstrahlung photons in the ...energy range 40–800 MeV with a resolution of ∼2 MeV and an overall flux of ∼10
8 s
−1.
The neutron magnetic form factor
G
mn
has been determined via a measurement of the ratio of cross sections
D(
e,
e′
n) and
D(
e,
e′
p). The absolute detection efficiency of the neutron detector was ...measured with high accuracy using tagged neutrons produced from
H(
n,
p)
n elastic scattering by means of a high intensity neutron beam. This approach minimizes the model dependence and improves upon the weakest points of previous experiments. Data in the range
q
2=0.2–0.8 (GeV/c)
2 with uncertainties of <2% are presented.
Rising energy costs, decreasing soil depth, and best management practices that require on-farm water retention have led to interest in flood-tolerant bioenergy crops for production in the Everglades ...Agricultural Area (EAA) of Florida. Information on the effects of high water tables on sugarcane (
Saccharum
spp. L.) is available; however, little is known about the bioenergy crops elephant grass (
Pennisetum purpureum
Schumach.), energycane (
Saccharum
spp. L.), and giant reed (
Arundo donax
L.). The objective of this study was to evaluate the role of water-table depth on the yields, morphology, physiology, and early season growth of these three bioenergy species in relation to sugarcane. The species were grown in a greenhouse and subjected to three water management strategies, −40 or −16 cm constant water-table depths, and bi-weekly flooding with drainage to −40 cm. The experiment was conducted in plant-cane, first-ratoon, and successive plant-cane crop cycles. Periodic flooding relative to a −40 cm constant water table significantly reduced dry weights and leaf area index and increased aerenchyma development. Averaged among crops, dry weight declined by 32, 49, 37, and 52% while leaf area index (LAI) decreased by 31, 50, 46, and 57% for giant reed, elephant grass, energycane, and sugarcane, respectively, in response to flooding. Aerenchyma proportional area of the stalk increased by 52, 90, and 95% for elephant grass, energycane, and sugarcane, respectively, but aerenchyma in giant reed decreased by 11%. High yields and stalk populations for all water tables were observed in energycane and elephant grass. These two species show potential for bioenergy production in the EAA. Field trials are recommended to confirm production scale yield.
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