Standardization of formats and presentation of fire data—the FDMS

Effective exchange of fire test data, even within a single laboratory, has been difficult due to the multiple, and often incompatible, data formats and hardware. This issue has been addressed by a careful study of user needs, leading to the development of a series of standard formats whereby fire test data could easily be exchanged among users. These formats have been made practical by the development of a computer program—the Fire Data Management System (FDMS)—and pertinent hardware standards. The system includes the most commonly used of modern-day fire test methods, but also has provisions for future extension to other tests of interest.     

Effect of osteoarthritis in the lumbar spine and hip on bone mineral density and diagnosis of osteoporosis in elderly men and women

To select for bacterial strains with enhanced phenotypes, random fragments of a whole genome, or a defined region of the genome, are cloned in a nonreplicating vector. The resulting plasmids are integrated by recombination into the homologous DNA region of the original strain. Integration gives rise to a nontandem direct duplication of the corresponding DNA region separated by the vector moiety of the plasmid. Recombination between the direct repeats leads to tandem duplication and further amplification of the entire integrated DNA, including the vector. Bacteria harboring the amplified DNA are selected by increasing the dosage of an antibiotic corresponding to a resistance marker of the integrated vector. Pooled strains carrying amplifications are then challenged with a selective pressure for the desired phenotype. After repeated selection cycles, the most fit strains are isolated. We used this process, which we called random DNA amplification, to select Rhizobium strains with increased competitiveness for nodule formation. Derivatives containing randomly amplified DNA regions of the symbiotic plasmid of Rhizobium tropici CFN299 strain were generated. Pools of amplified strains were inoculated onto various tropical legumes. After several cycles of selection through plants, amplified derivatives showing an increased competitiveness for nodule formation with the leguminous plant Macroptilium atropurpureum were obtained.     

Reactions During the Processing of U3O8—Al Cermet Fuels

The cermet fuel (U₃O₈ dispersed in Al) being considered for use in the Savannah River Site Reactors is thermodynamically unstable because of the potential for an exothermic metallothermic reduction reaction. This paper describes work performed to quantify the extent of reaction during powder metallurgy (P/M) processing of the U₃O₈—Al cermet fuel, and to determine the effect of partial reduction to U₄O₉ on the metallothermic reduction reaction. During the fabrication of the U₃O₈—Al cermet fuel by the P/M technique, a significant portion of the U₃O₈ is reduced to U₄O₉. The reaction between U₄O₉ and Al is also exothermic; however, the maximum heat released by the reaction is substantially less than that released for the U₃O₈—Al reaction, approximately 335 J (80 cal) per gram of oxide reacted compared to 940 J (225 cal). Metallothermic reduction reactions for U₃O₈/U₄O₉/Al mixtures do not occur at the normal reactor operating temperature, ∼ 370 K (∼ 100°C) or at temperatures below the melting point of aluminum, 930 K (660°C).     

Paget bone disease involving young adults in 3 generations of a Korean family

Pancreatic cancer is an aggressive disease with a dismal prognosis. It has long been regarded as one of the most difficult cancers to accurately diagnose and stage preoperatively. The purpose of this review is to provide an update of the state-of-the-art for early detection, diagnosis, and staging of pancreatic cancer. These methods include spiral CT scans, magnetic resonance imaging, positron emission tomography (PET) imaging, laparoscopy, endoscopic ultrasound, CA 19-9 serology, fine needle aspiration cytology, ERCP brush cytology, and screening for p53 and ras oncogenes. These advanced techniques should help us to detect pancreatic cancers in high-risk populations at a curative stage and to decrease pancreaticoduodenectomies for benign disease which could otherwise be treated with less morbid procedures. In addition, these tests will help reliably diagnose pancreatic cancer preoperatively.     

Peptide-mass fingerprinting and the ideal covering set for protein characterisation

The rules that govern the dynamics of protein characterisation by peptide-mass fingerprinting (PMF) were investigated through multiple interrogations of a nonredundant protein database. This was achieved by analysing the efficiency of identifying each entry in the entire database via perfect in silico digestion with a series of 20 pseudo-endoproteinases cutting at the carboxy terminal of each amino acid residue, and the multiple cutters: trypsin, chymotrypsin and Glu-C. The distribution of peptide fragment masses generated by endoproteinase digestion was examined with a view to designing better approaches to protein characterisation by PMF. On average, and for both common and rare cutters, the combination of approximately two fragments was sufficient to identify most database entries. However, the rare cutters left more entries unidentified in the database. Total coverage of the entire database could not be achieved with one enzymatic cutter alone, nor when all 23 cutters were used together. Peptide fragments of > 5000 Da had little effect on the outcome of PMF to correctly characterise database entries, while those with low mass (near to 350 Da in the case of trypsin) were found to be of most utility. The most frequently occurring fragments were also found in this lower mass region. The maximum size of uncut database entries (those not containing a specific amino acid residue) ranged from 52,908 Da to 258,314 Da, while the failure rate for a single cutter in identifying database entries varied from 10,865 (8.4%) to 23,290 (18.1%). PMF is likely to be a mainstay of any high-throughput protein screening strategy for large-scale proteome analysis. A better understanding of the merits and limitations of this technique will allow researchers to optimise their protein characterisation procedures.     

Regional contamination versus regional dietary differences: understanding geographic variation in brominated and chlorinated contaminant levels in polar bears

The relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (Ursus maritimus) contaminant levels is unknown. Dietary variation between Alaska, Canada, East Greenland, and Svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (δ(15)N, δ(13)C) and adipose fatty acid (FA) signatures relative to their main prey (ringed seals). Western and southern Hudson Bay signatures were characterized by depleted δ(15)N and δ(13)C, lower proportions of C(20) and C(22) monounsaturated FAs and higher proportions of C(18) and longer chain polyunsaturated FAs. East Greenland and Svalbard signatures were reversed relative to Hudson Bay. Alaskan and Canadian Arctic signatures were intermediate. Between-subpopulation dietary differences predominated over interannual, seasonal, sex, or age variation. Among various brominated and chlorinated contaminants, diet signatures significantly explained variation in adipose levels of polybrominated diphenyl ether (PBDE) flame retardants (14-15%) and legacy PCBs (18-21%). However, dietary influence was contaminant class-specific, since only low or nonsignificant proportions of variation in organochlorine pesticide (e.g., chlordane) levels were explained by diet. Hudson Bay diet signatures were associated with lower PCB and PBDE levels, whereas East Greenland and Svalbard signatures were associated with higher levels. Understanding diet/food web factors is important to accurately interpret contaminant trends, particularly in a changing Arctic.     

Model for the interpretation of hyperspectral remote-sensing reflectance

Remote-sensing reflectance is easier to interpret for the open ocean than for coastal regions because the optical signals are highly coupled to the phytoplankton (e.g., chlorophyll) concentrations. For estuarine or coastal waters, variable terrigenous colored dissolved organic matter (CDOM), suspended sediments, and bottom reflectance, all factors that do not covary with the pigment concentration, confound data interpretation. In this research, remote-sensing reflectance models are suggested for coastal waters, to which contributions that are due to bottom reflectance, CDOM fluorescence, and water Raman scattering are included. Through the use of two parameters to model the combination of the backscattering coefficient and the Q factor, excellent agreement was achieved between the measured and modeled remote-sensing reflectance for waters from the West Florida Shelf to the Mississippi River plume. These waters cover a range of chlorophyll of 0.2-40 mg/m(3) and gelbstoff absorption at 440 nm from 0.02-0.4 m(-1). Data with a spectral resolution of 10 nm or better, which is consistent with that provided by the airborne visible and infrared imaging spectrometer (AVIRIS) and spacecraft spectrometers, were used in the model evaluation.