A Pilot Survey of Vocal Health in Young Singers

The objective of this study was to determine the incidence of vocal problems in young choir singers and to correlate vocal problems with demographic and behavioral information. A questionnaire addressing vocal habits and hygiene was offered to 571 young choir singers, up to 25 years of age, who sing at least weekly; 129 (22.6%) responded. More than one-half of the respondents had experienced vocal difficulty, particularly older adolescents. Detrimental behaviors and circumstances surveyed were not reflective of the incidence of vocal difficulty, except for morning hoarseness, chronic fatigue, insomnia, and female gender after puberty. Voice care professionals should be aware that self-reported voice difficulties are common among young choral singers, especially postpubescent girls, and children with symptoms consistent with reflux (morning hoarseness) and emotional stress (insomnia). Laryngologists should communicate with choral conductors and singing teachers to enhance early identification and treatment of children with voice complaints, and to develop choral educational strategies that help decrease their incidence.     

Elevated plutonium and americium content in skulls of small mammals

It has been found that in skull bones of small mammals have significantly higher Pu and Am concentrations than ever found in bones of any other species in areas contaminated by global fallout. Since there was no difference between skulls of rodents and insectivorous, an explanation is proposed that the contamination takes place by the inhalation of Pu and Am tiny soil particles.     

Sr and stable strontium in bones of wild, herbivorous animals from Poland

Activity concentration of ⁹⁰ Sr and stable strontium concentration was analysed in 42 samples of animal (deer, roe-deer, elk and boar) bones, which mostly originated from north-eastern Poland. Strontium separation was performed by extraction chromatography. Determination of chemical yield was controlled by means of stable Sr determination using atomic spectrometry at the beginning and at the end of the separation procedure. Equilibrated ⁹⁰ Sr and ⁹⁰ Y activity was measured using a liquid scintillator spectrometer. Stable strontium range was from 55.4±1.7 ppm to 91.8±4.5 ppm, the mean was 71.84 ppm with a standard deviation (SD) of 9.31 ppm. The mean recovery of strontium was 26.7% with SD = 16.1%. The maximum activity of ⁹⁰ Sr, equal to 629±13 Bq/kg (ash) was found for a deer sample from Augustów Primeval Forest. In average, deer show the highest radiostrontium level, followed by roe-deer, elk and the lowest level were observed for boar. Differences between boar and deer or roe-deer are significant in terms of Kruskal-Wallis statistical test. Animal bones from north-eastern Poland showed about twice the mean concentration of ⁹⁰ Sr, compared to those of south-central Poland, but the difference was found not significant. Activities observed in roe-deer bones suggest the deposition of a concentration of 1.9 to 3.5 kBq/m² in the average of Chernobyl-origin ⁹⁰ Sr in 1986 in north-eastern Poland.     

Radioactive Contamination of Lichens and Mosses Collected in South Shetlands and Antarctic Peninsula

Samples belonging to two species of lichen and one of moss collected on the Antarctic seashore (King George Island, Deception, Antarctic Peninsula) were analysed for gamma-emitters using HPGe gamma-spectrometry, and for alpha-emitters using alpha-spectrometry with silicon detectors. Observed ¹³⁷Cs activities show large variations: from 4.1±0.4 to 74±3 Bq/kg. Total activity of ²¹⁰Pb changed from <2 to 125±35 Bq/kg. The ^2391240Pu activity ranged from 0.07±0.02 to 2.95±0.16 Bq/kg. The activity of ²³⁸Pu ranged from <0.02 to 0.64±0.04 Bq/kg. Maximum ²³⁸U and ²³⁴U activity was 7 Bq/kg, respectively, and 0.3 Bq/kg for ²³⁵U, whereas minimum activities were below 0.5 Bq/kg for ²³⁴U and ²³⁸U and about 0.02 Bq/kg for ²³⁵U. The ²³⁵U to ²³⁸U activity ratio for most of the samples was natural. Thorium activities were about two times lower than those for uranium. The activities of ¹⁴⁷Sm ranged from 0.014±0.002 to 1.0±0.2 Bq/kg. One sample had relatively high activity of ²⁴¹Am: 3.38±0.11 Bq/kg, another did not exceeded 1 Bq/kg. Observed activity ratios confirmed differences between mosses and lichen accumulation properties for radionuclides. Lichens are more selective for plutonium accumulation. Some radiocesium and probably also americium can be leached from them.     

Characterization of the Reaction of Chloroacetaldehyde with Single and Double Stranded DNA

Chloroacetaldehyde reacts with viral M13mp18 single and double stranded DNA to form the highly fluorescent adducts, etheno-AMP and etheno-CMP.

Absorbance and fluorescence spectroscopy can be used to monitor and characterize these reactions. Both single and double stranded DNA showed increases in the absorbance following reaction with the aldehyde. The fluorescence also increased in these two groups and continued to rise with increasing time of incubation until a point of saturation was reached. The fluorescence of the double stranded moiety was considerably enhanced following reaction with the aldehyde while that of the single stranded population was not, making this method appropriate for the separation of small quantities of the two populations of DNA.     

Application of the single comparator method to instrumental photon activation analysis

Journal of Radioanalytical and Nuclear Chemistry - Instrumental photon activation analysis (IPAA) is nondestructive and multi-elemental analysis method like instrumental neutron activation...