Low Q^2 Jet Production at HERA and Virtual Photon Structure

The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure

Acute epiglottitis in childhood: Report of an increased incidence in Victoria

The incidence of acute epiglottitis treated in Melbourne, Australia at the Royal Children's Hospital (RCH) has increased from an average of 14 cases per year during 1975-79 to 49 cases per year during 1980-81. Less marked increases have occurred for H. influenzae meningitis and bacteremia and H. influenzae (untyped) isolation from respiratory tract cultures. A review of 171 cases of acute epiglottitis showed no significant differences between the 1975-79 and 1980-81 patients with respect to sex, age, seasonal incidence, prodromal length, prodromal symptoms geographical location, polymorphonuclear cell count, or disease severity. Patients treated in 1980-81 had fewer complications (12% versus 22%,

In Vitro Measles Virus Infection of Human Lymphocyte Subsets Demonstrates High Susceptibility and Permissiveness of both Naive and Memory B Cells

Stemcel biology/Regenerative medicine (incl. bloodtransfusion

Sellar Region Atypical Teratoid/Rhabdoid Tumors (ATRT) in Adults Display DNA Methylation Profiles of the ATRT-MYC Subgroup

Atypical teratoid/rhabdoid tumor (ATRT) is a highly malignant brain tumor predominantly encountered in infants. Mutations of the SMARCB1 gene are the characteristic genetic lesion. A small group of ATRT stands out clinically, because these tumors are located in the sellar region of adults. To investigate if sellar region ATRT in adults represents a molecular distinct entity, we characterized molecular alterations in 7 sellar region ATRTs in adults as compared with 150 pediatric ATRTs and 47 pituitary adenomas using SMARCB1 sequencing, multiplex ligation-dependent probe amplification and fluorescence in situ hybridization as well as DNA methylation profiling. The median age of the 6 female and 1 male patients was 56 years. On histopathologic examination, all tumors were malignant rhabdoid tumors showing loss of SMARCB1/INI1 protein expression. Two cases displayed compound heterozygous SMARCB1 point mutations, 3 cases showed heterozygous SMARCB1 deletions with point mutations of the other allele and 1 case a homozygous SMARCB1 deletion; in 1 case, underlying SMARCB1 alterations could not be identified. On unsupervised hierarchical cluster analysis of DNA methylation profiles, sellar region ATRTs did not form a distinct group, but clustered with ATRT-MYC, 1 of 3 recently described molecular subgroups of ATRT. On analysis of DNA methylation array intensity data, only 1 sellar region ATRT showed characteristic features of pediatric ATRT-MYC, that is, major copy number losses affecting the SMARCB1 region. In conclusion, these results suggest that sellar region ATRTs in adults form a clinically distinct entity with a different mutational spectrum, but epigenetic similarities with pediatric ATRTs of the ATRT-MYC subgroup

ANALYTICAL EXTRACTION AND ENVIRONMENTAL REMOVAL OF ALKYLBENZENE SULFONATES, NONYLPHENOL AND NONYLPHENOL MONOETHOXYLATE FROM DATED SLUDGE-ONLY LANDFILLS

Exhaustive extraction of linear (LAS) and branched (TPS) alkylbenzene sulphonates, nonylphenol (NP) and nonylphenol monoethoxylate (NP1EO) from landfilled sludge were attained by using a polar solvent (methanol) and by adding sodium hydroxide (20%, w/w) to the dry sludge. In the absence of NaOH, or if moderately polar (dichloromethane) to apolar (hexane) solvents were used, poor extraction efficiencies ( 90%) over the same time period. The remarkably different behaviour of these compounds was ascribed to the landfill operating conditions, to be anaerobic when no biodegradation was observed, and aerobic when the title compounds were removed.Exhaustive extraction of linear (LAS) and branched (TPS) alkylbenzene sulphonates, nonylphenol (NP) and nonylphenol monoethoxylate (NP1EO) from landfilled sludge were attained by using a polar solvent (methanol) and by adding sodium hydroxide (20%, w/w) to the dry sludge. In the absence of NaOH, or if moderately polar (dichloromethane) to apolar (hexane) solvents were used, poor extraction efficiencies ( 90%) over the same time period. The remarkably different behaviour of these compounds was ascribed to the landfill operating conditions, to be anaerobic when no biodegradation was observed, and aerobic when the title compounds were removed

Monitoring aromatic surfactants and their biodegradation intermediates in raw and treated sewages by solid-phase extraction and liquid Chromatography

On the basis of solid-phase extraction, a simple procedure for determining simultaneously two aromatic surfactant classes, i.e., linear alkylbenzene sulfonates (LAS) and nonylphenol polyethoxylates (NPEO), as well as their biodegradation intermediates in raw and treated sewages is presented. This procedure involved passing 10 and 100 mL of an influent and effluent water sample, respectively, through a 1-g graphitized carbon black (GCB) extraction cartridge. By exploiting the presence of positively charged active centers on the GCB surface, we succeeded in fractionating the complex mixture of the analytes considered by differential elution. The first fraction contained NPEO and nonylphenol (NP). The second fraction contained the carboxylated biotransformation products of NPEO, i.e., nonylphenoxy carboxylic acids (NPEC). Finally, the last fraction contained LAS and their metabolites, i.e., carboxylic sulfophenyl acids (SPC). By suitably adjusting the chromatographic conditions, any group of analytes was subfractionated and quantified by liquid chromatography with fluorometric detection. Recoveries of all compounds of interest ranged between 89 % and 99%. This procedure was empolyed for 1 year to assess monthly the concentrations of the analytes considered in raw and treated sewages of a mechanical-biological treatment plant. © 1994 American Chemical Society