Line-shape modeling in microwave spectroscopy of the positronium n=2 fine-structure intervals

We report numerical simulations of positronium experiments designed to measure the n = 2 fine-structure intervals. The simulations include all possible interference effects between all 20 states in the n = 1 and laser-excited n = 2 manifolds as well as representations of the electric and magnetic fields present in the waveguides used in the experiments. We find that rf wave reflection from the vacuum chamber walls is a possible explanation of previously observed line-shape distortions and shifts. We also characterized several systematic effects, including those arising from quantum interference, that are likely to be significant for future measurements

Induction of beta defensin 2 by NTHi requires TLR2 mediated MyD88 and IRAK-TRAF6-p38MAPK signaling pathway in human middle ear epithelial cells

<p>Abstract</p> <p>Background</p> <p>All mucosal epithelia, including those of the tubotympanium, are secreting a variety of antimicrobial innate immune molecules (AIIMs). In our previous study, we showed the bactericidal/bacteriostatic functions of AIIMs against various otitis media pathogens. Among the AIIMs, human β-defensin 2 is the most potent molecule and is inducible by exposure to inflammatory stimuli such as bacterial components or proinflammatory cytokines. Even though the β-defensin 2 is an important AIIM, the induction mechanism of this molecule has not been clearly established. We believe that this report is the first attempt to elucidate NTHi induced β-defensin expression in airway mucosa, which includes the middle ear.</p> <p>Methods</p> <p>Monoclonal antibody blocking method was employed in monitoring the TLR-dependent NTHi response. Two gene knock down methods – dominant negative (DN) plasmid and small interfering RNA (siRNA) – were employed to detect and confirm the involvement of several key genes in the signaling cascade resulting from the NTHi stimulated β-defensin 2 expression in human middle ear epithelial cell (HMEEC-1). The student's <it>t</it>-test was used for the statistical analysis of the data.</p> <p>Results</p> <p>The experimental results showed that the major NTHi-specific receptor in HMEEC-1 is the Toll-like receptor 2 (TLR2). Furthermore, recognition of NTHi component(s)/ligand(s) by TLR2, activated the Toll/IL-1 receptor (TIR)-MyD88-IRAK1-TRAF6-MKK3/6-p38 MAPK signal transduction pathway, ultimately leading to the induction of β-defensin 2.</p> <p>Conclusion</p> <p>This study found that the induction of β-defensin 2 is highest in whole cell lysate (WCL) preparations of NTHi, suggesting that the ligand(s) responsible for this up-regulation may be soluble macromolecule(s). We also found that this induction takes place through the TLR2 dependent MyD88-IRAK1-TRAF6-p38 MAPK pathway, with the primary response occurring within the first hour of stimulation. In combination with our previous studies showing that IL-1α-induced β-defensin 2 expression takes place through a MyD88-independent Raf-MEK1/2-ERK MAPK pathway, we found that both signaling cascades act synergistically to up-regulate β-defensin 2 levels. We propose that this confers an essential evolutionary advantage to the cells in coping with infections and may serve to amplify the innate immune response through paracrine signaling.</p

Agroecological characterization of Xiphinema index in Spain1

The agroecological characteristics of Xiphinema index were determined by studying its spatial and temporal distribution in different environmental conditions in Spain. The host range, life cycle in the Mediterranean continental climate and its relationships with grapevine fanleaf nepovirus are also reported. X. index is widespread in grape‐growing areas in a wide range of soil textures and pH, even at high percentage of carbonates. However, it seems to prefer sandy‐loam and sandy‐clay loam soils, and populations decrease when soil carbonates increase. Its spatial distribution is random but it has a tendency to be found in the deepest clay horizons, where soil moisture is retained. Availability of moisture seems to be the limiting factor for nematode development. Grapevine and fig are the main host plants but X. index is also associated with fruit trees, ornamental crops, vegetable crops, woodlands and other uncultivated soils. Its life cycle in central Spain, where temperature ranges from <0°C until March to above 40°C from May—June until September, takes 6–8 weeks to complete. X. index was found in 14% of all vineyards sampled and in 50% of the fanleaf virus‐infected vineyards. Transmission tests using bait plants were successful and the detection of the virus by means of ELISA test in a mimimun of five nematodes was achieved. Fanleaf‐like symptoms often occurred in the absence of the virus, as demonstrated by ELISA. Copyright © 1994, Wiley Blackwell. All rights reserve