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At least 73 records · Page 4Linked to original sources
PubMed2000

Biologically weighted measurement of UV radiation in space and on Earth with the biofilm technique.

Biological dosimetry has provided experimental proof of the high sensitivity of the biologically effective UVB doses to changes in atmospheric ozone and has thereby confirmed the predictions from model calculations. The biological UV dosimeter 'biofilm' whose sensitivity is based on dried spores of B. subtilis as UV target weights the incident UV radiation according to its DNA damaging potential. Biofilm dosimetry was applicated in space experiments as well as in use in remote areas on Earth. Examples are long-term UV measurements in Antarctica, measurements of diurnal UV profiles parallel in time at different locations in Europe, continuous UV measurements in the frame of the German UV measurement network and personal UV dosimetry. In space biofilms were used to determine the biological efficiency of the extraterrestrial solar UV, to simulate the effects of decreasing ozone concentrations and to determine the interaction of UVB and vitamin D production of cosmonauts in the MIR station.

Bacillus subtilis↗
PubMed1977

Ribonucleic acid from the higher plant Matthiola incana. Molecular weight measurements and DNA-RNA hybridisation studies.

The percentage of DNA from the crucifer Matthiola incana coding for different types of RNA was measured by filter saturation hybridisation experiments using RNA labelled in vivo. In addition, the melting curves of the various DNA - RNA hybrids formed and the buoyant densities of the DNA sequences complementary to different types of RNA were measured. 1. The RNA preparations used were 25, 18, and 5 S rRNA and 4 S RNA, purified by gel electrophoresis, and poly(A)-containing RNA purified by oligo-(dT)-cellulose chromatography. The molecular weights of the 25 S and 18 S rRNAs, calculated from the mobility in formamide-acrylamide gels relative to Escherichia coli RNA, are 1.25 - 10(6) and 0.64 - 10(6). The rRNA precursor has a molecular weight of approx. 2.1 - 10(6) and the average molecular weight of the poly(A)-containing RNA from both cotyledons and roots is 4 - 10(5). 2. The percentage of the genome, calculated on the basis of double-stranded DNA, coding for these RNAs and the estimated number of genes per haploid DNA amount are approximately 0.46% and 1100 for 25 S plus 18 S rRNA, 0.032% and 3600 for 5 S rRNA and 0.072% and 13 000 for 4 S RNA. In filter hybridisation experiments very little hybridisation of poly(A)-containing RNA was found. A rapidly-hybridising component is attributed to small amounts of contaminating rRNA. 3. M. incana DNA has a main band at 1.697 g - ml-1 in CsCl and a satellite constituting approximately 3% of the DNA, at 1.708 g - ml-1 - 25 and 18 S rRNA hybridise to DNA with a buoyant density of 1.701--2 g - ml-1. The buoyant density of 5 S DNA is slightly less at 1.700--1 g - ml-1. 4. S RNA hybridises to at least two separate regions, one within the main-band DNA and a second lighter component. None of the RNAs tested hybridised to the satellite DNA. The Tm of the DNA - RNA hybrids in 1 X SSC is 89 degrees C for 25 S rRNA, 85 degrees C for 5 S rRNA and 82 degrees C for 4 S RNA. 4. 5 and 4 S RNA preparations contain fragments which hybridise to sequences complementary to high-molecular-weight rRNA. This spurious hybridisation can be eliminated by competition with unlabelled high-molecular-weight RNA.

Base Sequence↗
PubMed1975

The difference of pupa weight measurements in Tribolium and its effects on selection responses.

Possible causes of asymmetrical direct and indirect selection responses in Tribolium which were observed in a series of various experiments have been investigated. In some experiments the pupae were weighed just after pupation and in others they were weighed on the 20th day of incubation. Weight loss between pupation time and the 20th day of incubation as well as systematic differences in weight between individuals, pupating at successive ages are considered to be responsible for the asymmetry. The concept of unconscious secondary selection was introduced to interpret the asymmetrics of realized heritability and genetic correlation observed in two-way selection experiments.

Animals↗
PubMed1987

Accuracy of self-reported body weight compared to measured body weight. A population survey.

In 1977, in the evaluation of the prevention programme for cardiovascular diseases, 11,880 persons in Eastern Finland were asked to report their own weight on a questionnaire. Each participant was weighted during the following clinical examination. The data of the self-reported body weight were analysed according to sex, age, measured weight and body-mass index (BMI). The results showed that older people underestimated their weight to a greater extent than did younger people of both sexes. The error between measured and self-reported weight was greater in heavier subjects than in thinner individuals. In both sexes weight estimate error (measured weight minus self-reported weight) correlated more strongly with high BMI than with measured weight. Associations between weight estimate error and other variables were studied using a multiple regression model. Men whose annual family income was low were more likely to underestimate their weight than the men with a high annual income. In general, women reported their weight more correctly than men did. Older women were more likely to report their weight less than younger women, whereas women who visited their doctor frequently or who had higher annual family incomes were more aware of their actual body weight than those who had few doctor's consultations or whose family income was low. In men 5.2% and in women 8.3% of the variation in the weight estimate error was explained by the regression model.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1996

A comparison of risk assessment of single and combination manual handling tasks: 1. maximum acceptable weight measures.

Many manual handling activities involve combinations of pull, lift, carry, lower and push, yet few studies have investigated how to assess the risk of such combination tasks. Most recommendations assume that a combination task can be split into its components for assessment. The aim of this study was to compare the risks assessed in single manual handling tasks with those in combination tasks. Nine male and nine female students participated in a study to determine Maximum Acceptable Weights (MAWs) in single and combination tasks at different frequencies (1 min-1 and 3 min-1 for combination tasks and 3 min-1 and 6 min-1 for single tasks) and heights (floor, knuckle, shoulder). Combination tasks consisted of one each of the single tasks (pull, lift, carry, lower and push). The MAW of each combination task was compared to the MAWs of the single tasks of which it was composed using repeated measures analysis of variance with specified contrasts. In at least one of the 12 comparisons each single task MAW was found to be different from its related combination task MAW. It was concluded that the current use of single task MAWs to estimate the risk in combination tasks was unacceptable. Prediction models for combination task MAWs based on single tasks MAWs were also developed, using step-wise regression. Although coefficients of determination of around 0.8 were achieved it was argued that owing to their situation-specific nature the prediction of combination task risk using single task MAWs was likely to result in unacceptable risk errors.

Accidents, Occupational↗
PubMed1994

Height and weight measurements of male Turkish adolescents according to biological maturation.

Eight hundred and seventy-nine Turkish male adolescents aged between 11 and 19 years were investigated with respect to their physical development. Bone ages were considered as well as chronological ages in determining biacromial (BAC), biiliac lengths (BIC) and chest circumference (CC). Different bone and chronological ages were obtained at the same chronological age (CA) and bone age (BA) columns. The importance of bone ages in evaluating an adolescent's physical development was shown to be as important as the chronological ages. In this study, the mean BAC, BIC and CC values between the same CA but different BA groups showed statistically significant differences (P < 0.001). When the measurements of two consecutive age groups who had the same CA and BA and who were found to be statistically significant (P < 0.05) were compared, the maximum increments in BAC and BIC values which were between 13 and 14 years of age (2 and 1.4 cm, respectively) were similar to the maximum increment in height and weight of Turkish male adolescents found between 13 and 14 years of BA. The maximum increment in CC values which were between 14 and 15 years and 15 and 16 years (4.1 cm each) was 1 year after the maximum increment in height and weight for BA of Turkish male adolescents (13-14 years) and was similar to maximum weight increment for CA which was between 15 and 16 years.

Adolescent↗
PubMed1989

Measured weight loss and the dexamethasone suppression test.

In a prospective study of 28 subjects with major depression, weight was significantly related to nonsuppression in the dexamethasone suppression test (DST) on admission and seven days later. However, changes in weight between these two times did not alter the DST status.

Adolescent↗