Comparison of the acceptability ratings of appetizers under laboratory, base level and high altitude field conditions

The relationship between laboratory and field ratings was investigated for six different appetizers, including four ready-to-reconstitute mixes and two ready-to-eat munches. Liking ratings on a 5-point hedonic scale were obtained from an Indian Army field study at base level as well as at an altitude of 11,500 ft above sea level and for the same appetizers in the laboratory. The field trials of the six products were conducted in two phases and results revealed that the products were more acceptable at altitude, with increased liking scores as compared to base level. Subjective ratings for hunger revealed that at altitude, appetizer consumption had stimulated the appetite of the soldiers. The ability of laboratory ratings to predict acceptability of foods consumed under realistic conditions appears to depend on the convenience of the appetizer as well as the environmental conditions and the psycho-physiological status of the participants. The appetizers received higher ratings at altitude because of the pungent and spicy nature of appetizer mixes as compared with base field and laboratory conditions. However, for all the appetizers the pungent and sweet taste of the appetizer munches was highly preferred.     

Reproducibility of pulmonary function tests under laboratory and field conditions.

The reproducibility of pulmonary function tests in the laboratory and in a mobile field survey vehicle has been studied. Groups of laboratory workers were studied at base and a random sample of 38 coalminers was examined in the mobile laboratory. The intra-subject variability of some newer tests of lung function, including closing volume and maximum flow at low lung volumes, has been compared with that of well-established tests, such as lung volumes and forced expiratory volume from two measurements made more than one day apart. Most measurements were slightly less reproducible in the study of coalminers than in the laboratory personnel. Conventional tests, such as forced expiratory volume in one second, lung volumes, single breath CO transfer factor, and exercise ventilation were very reproducible, the coefficients of variation (cov) being generally between 5% and 10%. The closing volume test, maximum expiratory flow at low lung volumes, and the single breath N2 index were less reproducible: cov between 15% and 39% in the miners. The forced expired time and volume of isoflow, measured only on laboratory workers, however, exhibited greater reproducibility than previously reported (cov = 10% and 15% respectively). It is suggested that, when assessing the repeatability of lung function tests, account should be taken of the circumstances in which the intra-subject variability was measured.     

A comparison of the bioaccumulation potential of three freshwater organisms exposed to sediment-associated contaminants under laboratory conditions

In the field of sediment quality assessment, increased support has been expressed for using multiple species that represent different taxa, trophic levels, and potential routes of exposure. However, few studies have compared the bioaccumulation potential of various test species over a range of sediment contaminants (hydrophobic organics and metals). As part of the development and standardization of a laboratory bioaccumulation method for the Ontario Ministry of the Environment, the oligochaete Lumbriculus variegatus, mayfly nymph Hexagenia spp., and juvenile fathead minnow Pimephales promelas were exposed to a variety of field-contaminated sediments (n?=?10) to evaluate their relative effectiveness for accumulating different contaminants (e.g., dichlorodiphenyltrichloroethane [DDT] and metabolites, polychlorinated biphenyls [PCBs), polycyclic aromatic hydrocarbons [PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans [PCDD/Fs), and heavy metals). Bioaccumulation was usually highest in L. variegatus but also most variable within and (relative measures) between sediments. Bioaccumulation was similar between L. variegatus and Hexagenia spp. in most of the sediments tested. Significant differences in bioaccumulation between species were observed for DDT, dichlorodiphenyldichloroethane (DDD), PAHs, and PCDD/Fs. The present study indicates that species-specific differences in bioaccumulation may, but do not always, exist and can vary with contaminant and sediment type. The choice of test species or combination to use in a standard test method may depend on the objectives of the sediment quality assessment and data requirements of an ecological risk assessment. The results of the present study provide insight for selection of test species and validation of laboratory methods for assessing bioaccumulation with these species, as well as valuable information for interpreting results of bioaccumulation tests.     

The behavior of linear alkylbenzenesulfonate in different soils: a comparison between field and laboratory studies

The behavior of linear alkylbenzenesulfonate (LAS) in soils (i.e., degradation, percolation, and sorption) was investigated in field and laboratory tests. For this purpose sorption studies were carried out using Freundlich's method in order to obtain sorption constants. A prediction of sorption constants in characterized soils was possible using multiple regression and correlation methods. Degradation under laboratory conditions can faithfully be used for the interpretation of degradation times under field conditions. In laboratory tests LAS has reacted immobilely as in field tests. The uptake of LAS in plants is very high; however, it is slowly metabolized.     

A comparison of vibrotactile thresholds obtained using different diagnostic equipment: the effect of contact conditions

OBJECTIVES: Vibrotactile thresholds on the fingers were compared using two alternative methods of controlling contact with a vibrating probe: control of the force of contact with the probe (force control) and control of skin indentation produced by the probe (indentation control). Both systems had the same control of push force on a static surround around the vibrating probe. METHOD: A group of 14 male subjects (aged 20-27 years) were tested at four frequencies (31.5, 63, 125, 250 Hz) in three separate sessions so as to quantify the repeatability of thresholds. Skin stiffness was also measured. RESULTS: Control of skin indentation gave more repeatable thresholds than control of probe force. There was a practice effect whereby thresholds became more consistent over sessions. There were no systematic correlations between thresholds and skin stiffness. CONCLUSIONS: Repeatable and similar vibrotactile thresholds can be obtained with two alternative methods having different contact conditions. Either method may assist the diagnosis of disorders associated with hand-transmitted vibration, but control of skin indentation has the advantage of greater simplicity and, in this study, greater repeatability.     

Drinking water test methods in crisis-afflicted areas: comparison of methods under field conditions

To simplify the testing of drinking water in crisis-afflicted areas (as in Kosovo in 2007), rapid test methods were compared with the standard test. For Escherichia coli and coliform pathogens, rapid tests were made available: Colilert(?)-18, P/A test with 4-methylumbelliferyl-β-D-glucoronid, and m-Endo Broth. Biochemical differentiation was carried out by Enterotube? II. Enterococci were determined following the standard ISO test and by means of Enterolert?. Four hundred ninety-nine water samples were tested for E. coli and coliforms using four methods. Following the standard method, 20.8% (n=104) of the samples contained E. coli, whereas the rapid tests detected between 19.6% (m-Endo Broth, 92.0% concordance) and 20.0% (concordance: 93.6% Colilert-18 and 94.8% P/A-test) positive samples. Regarding coliforms, the percentage of concordant results ranged from 98.4% (P/A-test) to 99.0% (Colilert-18). Colilert-18 and m-Endo Broth detected even more positive samples than the standard method did. Enterococci were detected in 93 of 573 samples by the standard method, but in 92 samples by Enterolert (concordance: 99.5%). Considering the high-quality equipment and time requirements of the standard method, the use of rapid tests in crisis-afflicted areas is sufficiently reliable.     

Study of plutonium migration and/or accumulation in soil under field and laboratory conditions

This study investigated the dependence of Pu3+ and Pu4+ vertical distribution on the soil characteristics in soddy and forest soil. Soil samples were analysed for organic matter and pH. Special columns with contaminated (239Pu) soil surface were kept for 326 days under field conditions. The analysis of the contaminated soil layers (5 cm each, totalling 20 cm) showed that 81% of 239Pu4+, 44% of 239Pu3+ and 82% of 239Pu4+, 61% of 239Pu3+ were accumulated in the 0-5 cm layer of soddy and forest soil. Sequential extraction of the soddy soil 30 days after surface contamination with 239Pu, 137Cs and 90Sr showed the following differences in radionuclide distribution: the largest amount of 239Pu (60%) and 137Cs (70%) were extracted from the residual fraction while 90Sr in this fraction reached only about 10%. This suggests that organic substances and some inorganic compounds, which usually are the main components of the residual fraction, affect the retention and migration of plutonium in the soil.     

Metal effects on fathead minnows (Pimephales promelas) under field and laboratory conditions

The consequences of low-level metal exposure to early life stages of fathead minnows (Pimephales promelas) were investigated along a contamination gradient near Sudbury, Canada. Field exposures resulted in elevated hatching time and increased mortality in metal-contaminated lakes, in contrast to laboratory exposures where no effects were observed. Dissolved and ionic Cd and Ni were associated with changes in hatching time and larval mortality under field conditions, though other potential contaminants were not examined and may also have had an influence. The increased biological response of field-exposed fish, relative to fish exposed to the same water in laboratory conditions, may be the result of higher stress in natural environments, which could sensitize fish to contaminants. Analysis also indicated that, as contamination increases, the discrepancies between laboratory and field estimates of effect also increase. A temperature versus hatching time relationship was also quantified for fathead minnows.     

Parity of Ochlerotatus scapularis in laboratory and field conditions

OBJECTIVE: To identify the parity status of Ochlerotatus scapularis females in laboratory and field conditions. METHODS: Field collections were carried out fortnightly using a hand-held aspirator in Vale do Ribeira, Southeastern Brazil, from April 2003 to March 2004. In laboratory, 100 Ochlerotatus scapularis F1 females were obtained and followed up individually, reporting the number of blood meals, the length of gonotrophic cycle, survival and number of eggs laid. The parity status and ovarian development were observed through ovarian dissection of 90 field females for each collection and all females reared in laboratory. RESULTS: The parity status diagnoses of the 100 females reared in laboratory and dissected agreed with 55% of the oviposition data, and it was underestimated in 37% and overestimated in 2%. Also in the laboratory, 106 gonotrophic cycles were completed, around 55% of females needed more than one blood meal before laying eggs. In laboratory conditions the species survival was 26 days. A total of 1,180 field females of Ochlerotatus scapularis were dissected: 418 (35.4%) nulliparous, 655 (55.5%) uniparous, 46 (3.9%) biparous and 61 (5.2%) could not be evaluated. Ninety field females were found in Christophers and Mer's phase III-V. CONCLUSIONS: The gonotrophic discordance hypothesis could be confirmed based on field and laboratory observations of Ochlerotarus scapularis females.     

Studies on trachoma. 11. Evaluation of laboratory diagnostic methods under field conditions

The severity of trachoma in endemic areas has, in general, a tendency to decrease as a consequence of control measures and gradual improvements in sanitation and living conditions. The number of mild cases seen where the disease is prevalent is thus increasing and it is becoming more difficult to establish a differential diagnosis in certain cases, and to determine the degree of endemicity of the disease in a given area or community.     

Information and consumer choice: the value of publicized health plan ratings

We use data on the enrollment decisions of federal annuitants to estimate the influence of publicized ratings on health plan choice. We focus on the impact of ratings disseminated by the National Committee for Quality Assurance (NCQA), and use our estimates to calculate the value of the information. Our approach exploits a novel feature of the data-the availability of non-public plan ratings-to correct for a source of bias that is inherent in studies of consumer responsiveness to information on product quality: since publicized ratings are correlated with other quality signals known to consumers (but unobserved by researchers), the estimated influence of ratings is likely to be overstated. We control for this bias by comparing the estimated impact of publicized ratings to the estimated impact of ratings that were never disclosed. The results indicate that NCQA's plan ratings had a meaningful influence on individuals' choices, particularly for individuals choosing a plan for the first time. Although we estimate that a very small fraction of individual decisions were materially affected by the information, for those that were affected the implied utility gains are substantial.     

Isoform-specific quantification of metallothionein in the terrestrial gastropod Helix pomatia. II. A differential biomarker approach under laboratory and field conditions

The two function-specific metallothionein (MT) isoforms characterized from the midgut gland and mantle tissue of Helix pomatia differ substantially in their metal-binding preferences, as well as molecular and biochemical features. These differences make them potential candidates for biomarker studies based on a differential, isoform-specific approach. To prove this hypothesis, induction experiments with two metals (Cd and Cu) that are normally bound by the two isoforms were compared with a range of organic chemicals and physical stressors under laboratory conditions to test the responsiveness of the two isoforms to the stressors applied. In addition, field studies were conducted with Roman snails and substrate samples collected from different metal-contaminated sites in Austria to test the suitability of the two isoforms as biomarkers under field conditions. The results of these combined laboratory and field studies confirmed the validity of the biomarker approach with the two metal- and tissue-specific isoforms. It is demonstrated that the Cd-binding MT specifically and exclusively responds to Cd exposure by increasing concentrations, whereas the Cu-binding MT isoform decreases in its concentration upon exposure to physical stress (X-ray irradiation and cold). This suggests researchers should adopt, under certain preconditions, a dual biomarker approach by combining the simultaneous quantification of Cd-MT concentrations in the midgut gland as a biomarker for Cd pollution and of Cu-MT concentration in the mantle as a biomarker for the impairment of snails by additional physical stressors.