A
bstract
The Borexino detector measures solar neutrino fluxes via neutrino-electron elastic scattering. Observed spectra are determined by the solar-
ν
e
survival probability
P
ee
(
E
), and the ...chiral couplings of the neutrino and electron. Some theories of physics beyond the Standard Model postulate the existence of Non-Standard Interactions (NSI’s) which modify the chiral couplings and
P
ee
(
E
). In this paper, we search for such NSI’s, in particular, flavor-diagonal neutral current interactions that modify the
ν
e
e
and
ν
τ
e
couplings using Borexino Phase II data. Standard Solar Model predictions of the solar neutrino fluxes for both high- and low-metallicity assumptions are considered. No indication of new physics is found at the level of sensitivity of the detector and constraints on the parameters of the NSI’s are placed. In addition, with the same dataset the value of sin
2
θ
W
is obtained with a precision comparable to that achieved in reactor antineutrino experiments
.
Resolving the physiological mechanisms by which rhizobacteria enhance plant growth is difficult, since many such bacteria contain multiple plant growth-promoting properties. To understand further how ...the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCd)-containing rhizobacterium Variovorax paradoxus 5C-2 affects plant growth, the flows and partitioning of mineral nutrients and abscisic acid (ABA) and ABA metabolism were studied in pea (Pisum sativum) plants following rhizosphere bacterial inoculation. Although root architecture was not affected, inoculation increased root and shoot biomass, and stomatal conductance, by 20, 15, and 24%, respectively, and increased N, P, K, Ca, and Mg uptake by 16, 81, 50, 46, and 58%, respectively. P deposition in inoculated plant roots was 4.9 times higher than that in uninoculated controls. Rhizobacterial inoculation increased root to shoot xylem flows and shoot to root phloem flows of K by 1.8- and 2.1-fold, respectively. In control plants, major sinks for K deposition were the roots and upper shoot (43% and 49% of total uptake, respectively), while rhizobacterial inoculation increased K distribution to the lower shoot at the expense of other compartments (xylem, phloem, and upper shoot). Despite being unable to metabolize ABA in vitro, V. paradoxus 5C-2 decreased root ABA concentrations and accumulation by 40–60%. Although inoculation decreased xylem ABA flows, phloem ABA flows increased. Whether bacterial ACCd attenuates root to shoot ABA signalling requires further investigation, since ABA is critical to maintain growth of droughted plants, and ACCd-containing organisms have been advocated as a means of minimizing growth inhibition of plants in drying soil.
Haemophilia is characterized by intra‐articular bleeding, often requiring immobilization, which may result in muscle atrophy and impaired proprioception. The aim of the study was to investigate ...differences in proprioceptive performance and isometric muscular strength of the lower limbs in haemophilic subjects compared with control subjects. Twelve subjects with severe haemophilia (11 haemophilia A; one haemophilia B) vs. 12 control subjects were matched for anthropometric data and tested for differences of proprioception (one‐leg‐stand, posturomed, angle‐reproduction, and tuning fork tests) and isometric strength (leg press, knee extensor). The static proprioceptive performance of the haemophilic group, as measured by the one‐leg‐stand test (on hard or soft ground, with open or closed eyes; P < 0.05) was demonstrably impaired (by 41–363%). In contrast, the dynamic proprioceptive perfomance measured by the posturomed test did not show any difference between the groups. The local proprioceptive performance (angle‐reproduction test) of the knee, (the most commonly affected joint in haemophiliacs) showed a trend to impaired function but was not distinctly different from that of controls. The quantitative sensory function (tuning fork) showed significant (P < 0.05) impairment of 9–10% in the haemophilic subjects. Additionally, the isometric muscular strength of the leg extensor was weaker (32–38%) in the haemophilic group when the limbs were tested individually as well as bilaterally (P < 0.05). In conclusion, the results suggest that global proprioceptive performance is impaired and that the isometric strength of the leg extensors is weaker in the haemophilic subjects. Therefore, specialized training for global proprioception would be helpful in order to compensate for proprioceptive deficits. This exercise regimen should also include safe strength‐training for an optimal stabilization of the joints, but must be adapted to the individual needs and situations of the haemophilic subjects.
Orobanche species are holoparasites which are very efficient sinks for host-derived solutes. Here, we report the use of direct measurements of xylem sap solute concentrations and water fluxes, ...together with a modelling procedure to calculate element fluxes within an association between Orobanche cernua and its tobacco host. Infection of tobacco by the parasite markedly influenced carbon acquisition and partitioning; net fixation of carbon was 20% higher in infected tobacco compared with controls. Orobanche cernua caused a 84% increase in net carbon flux moving downward from the tobacco shoot and 73% of this carbon was intercepted by the parasite, almost entirely through the phloem (>99%). Further, the parasite also exerted a large impact on the nitrogen relations of the plant, notably nitrate uptake was stimulated and the amino acid content of xylem sap was lower. The parasite also relied heavily on host phloem for the supply of other resources, with only 5 to 15% of N, and 16% of K, 23% of Na, 63% of Mg and 13% of S being derived from the xylem. Thus, we provide quantitative information on the phloem dependency of the parasite and show that host carbon and nitrogen metabolism is stimulated as a consequence of infection.
The facultative hemiparasite Rhinanthus minor was grown alone,
or with either Hordeum vulgare or Trifolium
alpestre as a host. All plants were fed 5 mM nitrate. In the parasites,
successful ...attachment led to dramatic
increases in growth (particularly with barley as host) and in tissue concentrations
of total N, NO3−, H2PO4−
and K+, as well as moderate increases in Cl− and
SO42−. Mg2+ and Ca2+
concentrations either remained unchanged,
increased or decreased, depending on the host. Xylem sap was collected from leaf veins (barley) or the stem
(Rhinanthus and clover), by applying pneumatic pressure to the rooted soil to raise the soil water potential so that
in vivo xylem sap exuded from small incisions once the applied pressure balanced the tension exerted by
transpiration. High balancing pressures were needed for unattached Rhinanthus, whereas simultaneous collection
of xylem sap from attached Rhinanthus and its host, at a much lower balancing pressure, was possible only when
the parasite was enclosed in polyethylene film and high transpiration abolished. From plots of xylem sap volume
flow versus applied pressure, the hydraulic conductivity Lp
and the overall hydraulic resistance r were obtained.
The value of r was high in unattached Rhinanthus and dramatically decreased by attachment to a host, highlighting
the improved access to water gained by Rhinanthus when parasitizing a host. For the parasites, attachment resulted
in greatly increased concentrations and solute flow rates in xylem of
K+, NO3−, H2PO4−
and amino acids, and decreased concentrations of Ca2+ and Mg2+.
Estimates of NO3− reduction in the parasite showed that 99% was
reduced in unattached plants, 85% in those attached to clover and 52% in those attached to barley. In the
parasitized hosts, ion concentrations in xylem sap were somewhat increased relative to unparasitized controls.
Conversely, xylem sap amino-acid concentrations in infected hosts were decreased. Glutamine (Gln) was the
principal amino acid in xylem sap of unattached Rhinanthus, but after attachment to both hosts asparagine (Asn)
predominated. In clover, Asn was the major transport amino acid, suggesting massive transfer of Asn from host
to parasite. In unparasitized barley, however, Gln was the major xylem sap amino acid, but unexpectedly, in this
species Asn was induced as the principal amino acid when parasitized. The results are discussed in terms of mutual
host–parasite interactions.
ABSTRACT
Ricinus communis L. was grown under limiting N supply in quartz sand culture, fed with 0.2, 1 or 5 mol m−3 NO3−, or in liquid culture with 0.022, 0.05 or 0.5 mol m−3 NO3−. Some of the plants ...were infected with Cuscuta reflexa Roxb. As occurred for the host, dry matter production and growth of C. reflexa were severely depressed with decreasing N supply to the host. When parasitized by C. reflexa, the shoot and root dry weight of Ricinus was diminished at all levels of N nutrition, but the total dry weight of host plus parasite was almost the same as that of uninfected Ricinus. In contrast to the situation in Lupinus albus (Jeschke et al. 1994b), infection by Cuscuta resulted in increased tissue N levels in the host and the N content of the system Ricinus plus C. reflexa was the same or even somewhat larger than that of uninfected plants. This indicated a sink‐dependent stimulation of nitrate uptake. As a result of decreased root weights, nitrate uptake g−1 FW was stimulated by 80, 60 or only 40% at 0.2, 1 or 5 mol m−3 nitrate supply. Increased nitrate uptake was reflected, particularly at low N supply, in xylem transport; xylem sap nitrate concentrations were substantially elevated, while those of amino acids were decreased in parasitized plants. This indicated an inhibition of nitrate assimilation in roots of parasitized plants under limiting N supply. Besides these effects on N relations, C. reflexa induced a substantial sink‐dependent stimulation of net photosynthesis in host leaves and a concomitant increase in stomatal opening and transpiration. This stimulation depended on the relative sink size induced by Cuscuta, on nitrogen nutrition and on leaf age, indicating that delayed senescence of leaves contributes to the overall effects of Cuscuta on its host. The Cuscuta‐induced inhibition of nitrate assimilation in the roots and the increase in nitrate uptake suggest that nitrate reduction was shifted towards the leaves in the presence of C. reflexa. The stimulating effects of C. reflexa in the Ricinus‐Cuscuta association are compared with the strongly inhibitory effects occurring in the tripartite association L. albus–Rhizobium–Cuscuta reflexa.
Cells capable of photosynthesis in the parasitic angiosperm Cuscuta reflexa Roxb. (dodder) are highly localized. Immunolocalization of ribulose-1,5 bisphosphate carboxylase-oxygenase (Rubisco) and ...autofluorescence of chlorophyll in transverse sections of stems showed that they were largely restricted to a band of cells adjacent to the vascular bundles, consequently, the concentrations of Rubisco and chlorophyll were low per unit area or fresh weight. When 14CO2 was supplied to stem segments of C. reflexa it preferentially accumulated in these cells adjacent to the vasculature. Although the conductance for CO2 movement to the cells containing chlorophyll and Rubisco was very low, both the light reactions and dark reactions of photosynthesis appeared to be functional. De-epoxidation of the xanthophyll-cycle pigments after exposure to high light, and the chlorophyll fluorescence parameters, photo-chemical quenching (qP), non-photochemical quenching (NPQ) and the quantum efficiency of photosystem II responded normally to changes in photon flux density, indicating functional light-driven electron transport. The response of CO2 exchange to photon flux density followed a typical hyperbolic curve, and positive rates of CO2 fixation occurred when external CO2 was increased to 5%. We propose that CO2 for carbon assimilation is derived from internally respired CO2 and that this layer of photosynthetic cells makes a positive contribution to the carbon budget of C. reflexa.
Inkjet Printing of Multilayer Capacitors JESCHKE, D; AHLFS, E; KRÜGER, K
Journal of microelectronics and electronic packaging,
07/2012, Letnik:
9, Številka:
3
Journal Article
Recenzirano
Capacitors are widely used passive components. Taking account of micro hybrid circuits, printed capacitors are desirable. However, today's screen printing technology results in very low specific ...capacitance per area, thus SMD components are usually preferred. In order to achieve a higher specific capacitance, simple plate capacitors are stacked to form multilayer components. Maskless inkjet printing allows for realization of such structures. To keep the process simple, in-between sintering is avoided; the entire component is cofired in one final step.
To define the geometry of the components, the general processability of the used material combination is first examined. Among other things, the extent to which the structures can be decreased in size without affecting their functionality is determined. In further experiments, the effects of thermal expansion and sinter shrinkage are analyzed.
To create multilayer capacitors, a second step takes place in which the design is completed. Vias are embedded to bypass the dielectric layer or the opposing electrode. When increasing the height of the structure, the aspect ratio that can be achieved by the printing process is considered.
PDF
