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[en] The Jacobi-Porstendoerfer room model, describing the dynamical behaviour of radon and radon progeny in indoor air, has been successfully used for decades. The inversion of the model-the determination of the five parameters from measured results which provide better information on the room environment than mere ratios of unattached and attached radon progeny-is treated as an algebraic task. The linear interdependence of the used equations strongly limits the algebraic invertibility of experimental results. For a unique solution, the fulfilment of two invariants of the room model for the measured results is required. Non-fulfilment of these model invariants by the measured results leads to a set of non-identical solutions and indicates the violation of the conditions required by the room model or the incorrectness or excessive uncertainties of the measured results. The limited and non-unique algebraic invertibility of the room model is analysed numerically using our own data for the radon progeny. (authors)
[en] The study was performed to investigate cephalometric similarity between parents and offspring of the Korean family by lateral cephalometric analysis. The lateral cephalograms consist of the 8 families comprising 16 parents, 5 sons and 7 daughters. In order to make an investigation of the similarity, 12 measuring points were set up, and 22 linear measurements on each depth, height and 5 angular measurements were made. The author drew up the profilograms to compare parents with offspring in each family group. The obtained results were as follows: 1. There was no common similarity on specific region between parents and offspring in each family group. 2. There was partial similarity between single parent and offspring. 3. The partial similarity between single parent and offspring was noted on the upper face in general.
[en] Some test must be applied to the low-level count data from alpha continuous air monitors (CAMs) to determine if the count is statistically significant (i.e., different from background). The test should also automatically account for different levels of background (i.e., ambient radon progeny concentrations). The method should, in other words, be as sensitive as possible, automatically desensitize when required, but in such a manner as to not exceed a previously-chosen acceptable false-alarm rate.
[en] Samples of 42 dura x pisifera progenies of Ekona, AVROS, Ghana and Nigeria oil palm varieties, each involving six pisifera, were used to determine the minimum sample size of their parents for obtaining statistical yield differences between varieties. The 95% confidence interval of differences between varieties decreased sharply and, hence, the precision of the test improved, when increasing the number of progenies from 6 to 30 and pisifera (involved) from 1 to 4 and then levelled off to a steady decrement. As a test of differences the confidence interval has only a power of 50%, being the probability that a false null hypothesis of zero difference between varieties is rejected. With a power of 80%, a sample of 60 progenies in three replications detects, depending on the variance of the pisifera parents, a significant yield difference of 4.5% between Nigeria and AVROS and 7% between Ghana and Ekona with 6 and 9 pisifera in the sample, respectively. The article argues to incorporate optimal planting density as a crucial trait in selecting oil palm varieties. This study offers a method to obtain unbiased progeny samples, along with a field lay out for bulk recording of progeny plots. (author)
[en] With 3-month simultaneous measurements of thoron and its progeny concentrations in the lowest floors of 109 homes, the geometric mean (GM) of thoron equilibrium factor was determined to be 0.019 with a geometric standard deviation (GSD) of 3.63. Combined with the analysis from results obtained from a previous study in 138 homes, the GM of thoron equilibrium factor was determined to be 0.022 with a GSD of 3.02. The results indicate that the F value of 0.02 for thoron recommended by UNSCEAR is a reasonable value for those Canadian homes tested. Published by Oxford Univ. Press on behalf of the Canadian Government 2011. (authors)
[en] To evaluate the equilibrium factor between radon and its progeny in air, the measurement system made up of opened solid state nuclear track detector and filtered one is established. The HURC(Hanyang University Radon Cup) is used as a detector chamber in combination with a CR-39 track detector. The methodology using track density ratio of two SSNTDs, suggested by Domanski, is used to determine the equilibrium factor. To test the validity of this relationship between the equilibrium factor and track density ratio, calibration experiments are carried out with the pair-cup system for radon and its progeny in the radon chamber at the National Radiological Protection Board(NRPB, UK). To test the performance of the pair-cup system, intercomparison experiments are carried out with another radon and its progeny detectors in radon chamber at the Korea Research Institute of Standards and Science(KRISS, Korea). The calibration factor associated with the filtered SSNTD for radon, obtained from calibration experiments, is 9.59±0.49 Bq·m-3 per tracks·cm-2·d-1 and the other is 1.6x10-3±1.6x10-4 WL per tracks·cm-2·d-1 for radon progeny. The results of the validity-test found that the methodology using the track density ratio between the open and filtered cup are applicable to determination of the equilibrium factor for a long-term exposure period, from 100 kBq·h·m-3 to 200 kBq·h·m-3 of accumulated radon concentration. Besides, the pair-cup system reflects well the change of equilibrium. The methodology and the established system can apply to measurement of the time-average equilibrium factor in underground mines or basements associated with high radon exposures
[en] The heritability of calcified intervertebral discs in the dachshund was estimated using data gathered from a radiographic study. Radiographs of the vertebral columns of 274 clinically normal, 12 to 18 months old dachshunds, were examined. The dogs were offspring from 75 different sires, representing the same number of half sib groups. There were 2 to 14 offspring in each half-sib group. The number of full sib groups was 81. Calcified intervertebral discs were identified in 20.4% of the dogs. An analysis of variance that used the data as a continuous and as an either/or-variable estimated the heritability of calcified discs to be 0.22 and 0.15 respectively. A genetic factor was found to be essential for the occurrence of calcified discs in a dog while a common environmental factor presumably resulting from non-genetic causes was significant in determining the number of discs to undergo calcification in affected dogs
[en] Dwarf male-sterile wheat is a new germplasm that linked the Taigu genic male-sterile gene Ms2 with Aibian1 dwarfing gene Rht10 tightly on the same chromosome 4DS with 0.18 crossing-over unit. The progeny of dwarf male-sterile wheat always segregates into 1:1 for male-sterile plants with dwarfing gene Rht10 and male-fertile plants without dwarfing gene Rht10. So the male-sterile plants are shorter than the male-fertile plants. It is very easy to identify male sterility plants based on plant height. Dwarf male-sterile wheat is favorable tool for wheat breeding in recurrent selection. A simple, effective and practical method in recurrent selection called the dwarf male-sterile wheat breeding system has been created. The new dwarf male-sterile wheat technical system consists of construction of a basic population, choice of male parent, selection of male-sterile plant and inter-crossing. Four new cultivars, i.e. RS981, RS987, RS518 and RS201 have been developed. Dwarf male-sterile wheat and its breeding technical system is an effective technology platform for wheat breeding in different ecological areas. (author)