New Experimental limit on Optical Photon Coupling to Neutral, Scalar Bosons

We report on the first results of a sensitive search for scalar coupling of photons to a light neutral boson in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 10$^-6$ GeV$^-1$ using optical photons. This was a photon regeneration experiment using the "light shining through a wall" technique in which laser light was passed through a strong magnetic field upstream of an optical beam dump; regenerated laser light was then searched for downstream of a second magnetic field region optically shielded from the former. Our results show no evidence for scalar coupling in this region of parameter space.Comment: pdf-file, 10 pages, 4 figures, submitted to Physical Review Letter

First lasing of the Jefferson Lab IR Demo FEL

As reported previously [1], Jefferson Lab is building a free-electron laser capable of generating a continuous wave kilowatt laser beam. The driver-accelerator consists of a superconducting, energy-recovery accelerator. The initial stage of the program was to produce over 100 W of average power with no recirculation. In order to provide maximum gain the initial wavelength was chosen to be 5 mu-m and the initial beam energy was chosen to be 38.5 MeV. On June 17, 1998, the laser produced 155 Watts cw power at the laser output with a 98% reflective output coupler. On July 28th, 311 Watts cw power was obtained using a 90% reflective output coupler. A summary of the commissioning activities to date as well as some novel lasing results will be summarized in this paper. Present work is concentrated on optimizing lasing at 5 mu-m, obtaining lasing at 3 mu-m, and commissioning the recirculation transport in preparation for kilowatt lasing this fall

The epithelial cholinergic system of the airways

Acetylcholine (ACh), a classical transmitter of parasympathetic nerve fibres in the airways, is also synthesized by a large number of non-neuronal cells, including airway surface epithelial cells. Strongest expression of cholinergic traits is observed in neuroendocrine and brush cells but other epithelial cell types—ciliated, basal and secretory—are cholinergic as well. There is cell type-specific expression of the molecular pathways of ACh release, including both the vesicular storage and exocytotic release known from neurons, and transmembrane release from the cytosol via organic cation transporters. The subcellular distribution of the ACh release machineries suggests luminal release from ciliated and secretory cells, and basolateral release from neuroendocrine cells. The scenario as known so far strongly suggests a local auto-/paracrine role of epithelial ACh in regulating various aspects on the innate mucosal defence mechanisms, including mucociliary clearance, regulation of macrophage function and modulation of sensory nerve fibre activity. The proliferative effects of ACh gain importance in recently identified ACh receptor disorders conferring susceptibility to lung cancer. The cell type-specific molecular diversity of the epithelial ACh synthesis and release machinery implies that it is differently regulated than neuronal ACh release and can be specifically targeted by appropriate drugs

Interfacial Reaction in Steel-Aluminum Joints Made by Friction Stir Welding

The reaction layers of friction stir welded joints made from austenitic stainless steel and Al alloy consisted of mixed layers of elongated and ultra-fine grains and the intermetallic compound layer. The intermetallic compound layer was identified as Al4Fe with a hexagonal close-packed structure and a thickness of approximately 250 nm. The elongated grains were shown to consist of a ferrite phase because of their ferromagnetism and a body-centered cubic crystal structure

Carriage of encapsulated bacteria in Gabonese children with sickle cell anaemia

AbstractSickle cell anaemia (SCA) is a haemoglobin disorder that alters the deformability of erythrocytes through abnormal polymerization of haemoglobin. Children with SCA have an increased risk of infections with encapsulated bacteria. To guide the antibiotic prophylaxis and vaccinations in children with SCA in Gabon, we characterized Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae from children with and without SCA. We performed a cross-sectional study and compared nasal and pharyngeal S. pneumoniae, Staph. aureus and H. influenzae isolates from SCA children (n = 73) with comparators matched for age, residence and sex (n = 143) in a matched-comparison analysis. The resistance pattern and capsular type were identified for each isolate. The total carriage rate for S. pneumoniae, Staph. aureus and H. influenzae was 13.8%, 46.7% and 12.5%, respectively, and did not differ between groups (p >0.05). The mean number of days under antibiotic treatment in the past year was higher in children with SCA than in controls (penicillin: 70.1 vs 0.1 days, p 0.00002). The total non-susceptibility rate was 30% for oral and parenteral (meningitis) penicillin in S. pneumoniae, resistance rates were 1.6% for oxacillin in Staph. aureus and 14.8% for ampicillin in H. influenzae. Susceptibility to antibiotic agents and distribution of capsular types did not differ significantly between both groups. In conclusion, carriage and resistance rates are similar in children with and without SCA. Our data provide the basis to guide empiric therapy of invasive diseases caused by S. pneumoniae, Staph. aureus and H. influenza in children in Gabon

Clonal structure of Staphylococcus aureus colonizing children with sickle cell anaemia and healthy controls

Children with sickle cell anaemia (SCA) might carry hospital-associated bacterial lineages due to frequent hospital stays and antibiotic treatments. In this study we compared Staphylococcus aureus from SCA patients (n=73) and healthy children (n=143) in a cross-sectional study in Gabon. S. aureus carriage did not differ between children with SCA (n=34, 46∙6%) and controls matched for age, residence and sex (n=67, 46∙9%). Both groups shared similar S. aureus genotypes. This finding points towards a transmission of S. aureus between both groups in the community. We conclude that resistance rates from population-based studies with healthy participants could therefore also be used to guide treatment and prophylaxis of endogenous infections in children with SCA despite a different selection pressur

The bridge between science and practice: Evidence of prevention and health promotion in the context of the structure and objectives of the interdisciplinary research network TRISEARCH

The social and political expectations towards lifestyle interventions are high. The research association TRISEARCH aims to develop recommendations for evidence development in lifestyle interventions as well as considering the quality perspective of practical partners. In this context, interdisciplinary research and development activities focus on workplace-related interventions that promote health literacy. The present article describes the structure and the aims as well as the content of the research association TRISEARCH