L- and P-selectin and CD11/CD18 in intracapillary neutrophil sequestration in rabbit lungs

Infusion of complement fragments induces rapid sequestration of neutrophils within pulmonary capillaries. This study examined the mechanisms through which this sequestration occurs, as well as the effect of complement fragments on the expression of L-selectin and CD11/CD18 using ultrastructural immunohistochemistry. Studies using anti-P-selectin antibodies, fucoidin, L- selectin-depleted neutrophils, and anti-CD18 antibodies showed that selectins and CD18 were not required for neutrophil sequestration. However, maintaining the sequestered neutrophils within the pulmonary capillaries required both L- selectin and CD11/CD18. Neutrophils in the pulmonary capillaries of rabbits given complement fragments expressed 72% less L-selectin and 98% more CD11/CD18 than did those in rabbits given saline. Shedding of L-selectin occurred preferentially from the microvillar processes of the plasma membrane rather than from the fiat intervening regions. About 28% of L-selectin still remained on intracapillary neutrophil membranes after 15 min and was likely available for binding. Shedding of L-selectin appeared slower in vivo than in vitro. These studies indicate that neutrophil sequestration induced by complement fragments requires at least two sequential steps, one that does not require recognized adhesion molecules followed by a second that requires L-selectin and CD11/CD18

Lymphocyte accumulation during Pseudomonas aeruginosa-induced pneumonia in rodents does not require CD11a and intercellular adhesion molecule-1.

During Pseudomonas aeruginosa-induced pneumonia in rodents, the acute infiltrate of neutrophils is followed by accumulation of lymphocytes in the perivascular connective tissue. The roles of the adhesion molecules CD11a/CD18 and intercellular adhesion molecule-1 (ICAM-1) in this accumulation of lymphocytes were investigated. The numbers of lymphocytes in P. aeruginosa-induced pneumonia were compared in animals treated with blocking antibodies to either CD11a, ICAM-1, IgG, or no antibody. In other experiments, the lymphocyte accumulation during P. aeruginosa-induced pneumonia in ICAM-1 mutant mice was compared with that in wild-type mice. In rats, both a murine anti-rat CD11a antibody and nonspecific murine IgG partially inhibited the lymphocyte accumulation by 30 to 40% compared with animals that received no antibodies. In mice, blocking antibodies to either CD11a or ICAM-1 did not decrease the lymphocyte accumulation compared with mice given IgG or no antibody. Further, there was no attenuation of the lymphocyte accumulation induced by P. aeruginosa in the ICAM-1 mutant mice compared with wild-type mice, either in the total number of lymphocytes or the number of CD4+, CD8+, or B cells. We conclude that neither CD11a/CD18 nor ICAM-1 are required for lymphocyte accumulation during P. aeruginosa-induced pneumonia in rodents. The partial inhibition of the lymphocyte accumulation in both the anti-CD11a- and IgG-treated rats may be due to nonspecific effects of foreign proteins on cellular functions

Magnetic trapping of ultracold neutrons

Three-dimensional magnetic confinement of neutrons is reported. Neutrons are loaded into an Ioffe-type superconducting magnetic trap through inelastic scattering of cold neutrons with 4He. Scattered neutrons with sufficiently low energy and in the appropriate spin state are confined by the magnetic field until they decay. The electron resulting from neutron decay produces scintillations in the liquid helium bath that results in a pulse of extreme ultraviolet light. This light is frequency downconverted to the visible and detected. Results are presented in which 500 +/- 155 neutrons are magnetically trapped in each loading cycle, consistent with theoretical predictions. The lifetime of the observed signal, 660 s +290/-170 s, is consistent with the neutron beta-decay lifetime.Comment: 17 pages, 18 figures, accepted for publication in Physical Review

Narrow genetic base in forest restoration with holm oak (Quercus ilex L.) in Sicily

In order to empirically assess the effect of actual seed sampling strategy on genetic diversity of holm oak (Quercus ilex) forestations in Sicily, we have analysed the genetic composition of two seedling lots (nursery stock and plantation) and their known natural seed origin stand by means of six nuclear microsatellite loci. Significant reduction in genetic diversity and significant difference in genetic composition of the seedling lots compared to the seed origin stand were detected. The female and the total effective number of parents were quantified by means of maternity assignment of seedlings and temporal changes in allele frequencies. Extremely low effective maternity numbers were estimated (Nfe $\approx$ 2-4) and estimates accounting for both seed and pollen donors gave also low values (Ne $\approx$ 35-50). These values can be explained by an inappropriate forestry seed harvest strategy limited to a small number of spatially close trees

Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares

The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature and density sensitive line ratios, Doppler shifted emission lines and nonthermal broadening, abundance measurements, differential emission measure profiles, and continuum temperatures and energetics, among others. In this paper I shall review some of the advances made in recent years using these techniques, focusing primarily on studies that have utilized data from Hinode/EIS and SDO/EVE, while also providing some historical background and a summary of future spectroscopic instrumentation.Comment: 34 pages, 8 figures. Submitted to Solar Physics as part of the Topical Issue on Solar and Stellar Flare

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results