Objective measures of research performance are necessary to facilitate academic advancement of trainee physicians. In this cross-sectional study, all anaesthetists (n = 98) in higher specialist training in Ireland were surveyed to determine bibliometrics of their scientific publications and individual and institutional characteristics that can influence research productivity. For trainees with publications, the median (range) h-index was 1 (0–4). There was a positive correlation between participation in a formal research program and increased research productivity using mean citations per publication (r2 = 0.26, P = 0.006) and h-index (r2 = 0.26, P = 0.006). There was a positive correlation between formal mentorship and mean citations per publication (r2 = 0.15, P = 0.04) and h-index (r2 = 0.17, P = 0.03).
Authors:W. D. James, E. S. Dahlin, and D. L. Carlson
Multielement analysis of archaeological artifacts for the purpose of correlating chemical composition in an effort to determine provenience has become a well-known and accepted procedure. In this study, inductively coupled plasma-mass spectrometry with laser ablation probe (LA-ICP-MS) for the direct study of solids was used to generate elemental data for comparison with existing instrumental neutron activation analysis (INAA) data. Matrix element Al was used as an internal standard in the ICP work to normalize for variations in sample density and sample mass ablated. While absolute accuracy and precision for the ICP data are inferior to INAA, multivariate statistical analysis of data resulting from the two methods demonstrates a high degree of comparability. Sample cluster assignments differed in only 4.7% (4 out of 86) of the cases. Results show a clear usefulness for LA-ICP-MS in archaeological compositional analysis.
Authors:Michael L. Hobbs, James T. Nakos, and Patrick D. Brady
Determining the response of composite phenolic materials to fire remains a major unsolved problem that is important for high consequence safety analysis. Difficulties arise when thermophysical property measurements are obscured by decomposition reactions. This article presents several decomposition experiments and models for a phenolic resin impregnated into chopped 1.27-by-1.27 cm glass fabric. The thermal response of the material was measured using thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and laser flash diffusivity (LFD). The TG data was used to develop a 5-step decomposition mechanism describing mass loss due to reaction; the DSC data was used to describe the energy changes associated with these reactions; and the LFD data was used to describe energy flow into the decomposing material. An effective thermal conductivity model was used to partition energy transport by gas conduction, solid conduction, and diffusive radiation. The dynamic gas volume fraction is treated as a field variable to extrapolate thermal transport properties at high temperatures where decomposition is prevalent. These various models have been implemented into a finite element response model with an example calculation that includes uncertainty.
Authors:E. Dahlin, D. Carlson, W. James, and H. Shafer
The distribution patterns of Classic Mimbres black-on-white bowls and jars were determined by instrumental neutron activation
analysis to identify vessel movement between geographically defined regions and between villages within individual regions
of southwestern New Mexico. The data set produced and utilized by the various multivariate statistical treatments included
multielement neutron activation analysis results for 288 ceramic and clay samples from 15 sites in the Gila, Mimbres and Rio
Grande valleys of southwest New Mexico. The results indicate that bowls were more frequently exchanged than jars and distribution
frequencies between regions were lower than between villages. Two statistical approaches to the data were compared. In one,
cluster analysis of the compositional data was used to form homogeneous groups and the distribution of those groups across
sites and regions was examined. In the second, discriminant analysis was used to look for significant differences in composition
between regions and sites. The significance of predetermining groups based on collection location as opposed to blind group
formation from hierarchical cluster analysis was evaluated in terms of its potential to lead to different interpretations
of the data.
Authors:C. Dunkley, W. Kim, W. James, W. Ellis, J. McReynolds, L. Kubena, D. Nisbet, and S. Ricke
A method has been developed for the study of passage rates and mean residence times (MRT) of test rations through the gastrointestinal
tracts of layer hens. The use of rare earth elements as stable indigestible markers monitored by neutron activation analysis
has been previously demonstrated in numerous species. In this study hafnium was used to mark corn and alfalfa rations as well
as a combination ration made up of 90% alfalfa and 10% corn. The primary goal of the study was to evaluate the potential for
use of rare earth stable markers in poultry digestion and to determine efficiency of meal marking, optimum exposure rates
and determination limits for use in the design of future experimental protocols. Three groups of 10 hens each were fed a particular
marked meal with fecal droppings monitored for 24 hours. The hens were sacrificed after a second dosed feeding and a delay
of two or seven hours, and digesta was collected from each portion of the gastrointestinal tract. Fecal dry matter as well
as digesta collected was then prepared for analysis and the elemental concentrations of hafnium were measured with instrumental
neutron activation analysis (INAA). Element adsorption on alfalfa was far less efficient than on the corn ration, limiting
the applicability of much of the alfalfa data to digestion studies. Passage rate curves were prepared for corn. The marker
was found to primarily concentrate in the ileum at both sacrifice times.
Authors:Z. Ali, D. James, W. O'Hare, F. Rowell, and S. Scott
An electronic nose utilising an array of six-bulk acoustic wave polymer coated Piezoelectric Quartz (PZQ) sensors has been developed. The nose was presented with 346 samples of fresh edible oil headspace volatiles, generated at 45°C. Extra virgin olive (EVO), Non-virgin olive oil (OI) and Sunflower oil (SFO), were used over a period of 30 days. The sensor responses were then analysed producing an architecture for the Radial Basis Function Artificial Neural Network (RBF). It was found that the RBF results were excellent, giving classifications of above 99% for the vegetable oil test samples.
Authors:Z. Ali, D. James, W. O'Hare, F. Rowell, and S. Scott
The effect of different relative humidity (RH) on the response of a six-polymer coated Quartz Crystal Microbalance (QCM) sensor based electronic nose (EN) was investigated, RH 30 and 50% respectively. Increases in the sensor responses were observed for an increase in RH. A stainless steel pre-concentration tube (PCT) containing Porapak-S and a nichrome heating element was developed to minimise the effect and allow for chromatographic pre-separation. Breakthrough times of chemical compounds through the PCT were experimentally determined and used to select a mixture of water and toluene as a suitable sample for pre-separation. The PCT was capable of separating the water from the toluene and the EN was competent at evaluating the concentration of toluene in the solution.
Authors:W. D. James, A. T. Showler, J. K. Westbrook, and J. S. Armstrong
Stable isotope markers have been used to study animal nutrition for several decades and more recently to study the foraging
and cultural habits of imported fire ants. In this work, we have extended that effort to evaluate the potential for marking
boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), with the rare earth element samarium to aid in studies of insect invasion and pest eradication protocols. Neutron activation
analysis (NAA) was performed on the marked boll weevils as well as plant material from the cotton squares on which the insects
were fed. Samarium levels in non-dosed insects average about 20 ng/g or about 100 pg total element per insect. Our computed
average determination limit was 36 pg samarium/weevil. The determination limit for cotton plant squares and leaves averaged
3.5 ng/g and 8.2 ng/g, respectively. These initial results indicate the NAA method is capable of identifying individual marked
insects which have assimilated 1 ng of samarium, a ten-fold increase in content over average blank values.
Authors:J. Dabek, D. Vartsky, P. Dykes, J. Hardwicke, B. Thomas, J. Fremlin, and H. James
Whole body nitrogen has been measured absolutely in male volunteers and patients by in-vivo neutron activation analysis using
whole body hydrogen as an internal standard. The 10.8 MeV and 2.2 MeV prompt gamma rays from nitrogen and hydrogen respectively
give a result reproducible to 4% for a dose of 100 mRem. Whole body potassium measured by whole body counting natural40K and whole body nitrogen have been correlated in normal adult males and patients. In the normals the correlation coefficient
was 0.96 with coefficient of variation 4%. In the patients these parameters were 0.92 and 8% in 140 measurements. The ratio
of N/K increased significantly as the degree of clinical wasting progressed.