H. Van de Voorde

The effect of thermal pollution on the distribution of Naegleria fowleri

The distribution in the environment of Naegleria fowleri, the causal agent of primary amoebic meningoencephalitis has been investigated in this study. N. fowleri was isolated only from a thermally polluted canal. These amoebaflagellates were not isolated from another thermally polluted canal in the neighbourhood indicating that, apart from high temperature, other factors are involved in the selective proliferation of N. fowleri. This species was absent in all other samples originating from two canals, a stream, two lakes, several reservoirs and slow sandfilters of a water supply service and also a water distribution network. Many other amoebae able to grow at 42 degrees C. were found in different places. Most of the N. fowleri strains isolated were not virulent for mice, although they showed all the characteristics of the pathogenic strains.

EVALUATION OF THE MODIFIED ZINC TEST AND THE ACID PHOSPHATASE TEST AS PRELIMINARY SCREENING METHODS IN SEXUAL ASSAULT CASE MATERIAL

The modified zinc test and a commercially available acid phosphatase test were compared as to their screening parameters according to the microscopical finding of spermatozoa in cases of alleged sexual assault. The study involved 65 pieces of evidence material. It was found that the modified zinc test has a higher sensitivity and higher predictive values than the acid phosphatase test. However, when both tests are combined in parallel, the sensitivity and the negative predictive value could be raised to 99%. This finding suggests that a negative result obtained from the parallel combination of the modified zinc test and the acid phosphatase test predicts very well that no spermatozoa will be found at microscopical examination. Since the latter technique is the only one to give absolute proof of the seminal origin of stains or traces, the parallel combination of the zinc test and the acid phosphatase test might be useful in sorting out these cases or materials that deserve further investigation by more elaborate techniques.

A more sensitive modification of the zinc test for seminal traces suitable for stable test paper strips

A more sensitive modification of the zinc test for semen has been developed, which can be used either as a solution or incorporated into test papers. The latter retain their sensitivity for at least 3 months.

Effects of road salt in winter

Abstract The salt concentration in three streams and soils was studied during a two-year period in order to discover the effect of salt treatment of roads in winter. Scattered salt enhances slightly, for a 24 h period, chloride concentration in the river which crosses a city. In a rural stream the salt concentration reaches a high level for a short period. In the rivers or streams the scattered salt is quickly diluted so that the normal chloride level remains unchanged. The amount of the salt deposited on the banks of the roads filters down to the phreatic water and locally enhances the chloride concentration of the groundwater but not to a concentration which can be considered harmful to the health of consumers. Other minor disadvantages of road salt are damage to ornamental vegetation and corroding effect on metallic surfaces. The hazards of the use of road salt are, however, negligible compared with traffic safety.

Nuclear moments in the doubly odd 132I isotope

Abstract The nuclear moments of the 50 keV, I = 3 + and 278 keV, I = 1 + states in 132 I are measured by perturbed angular correlation techniques, using the quadrupole interaction of iodine in a tellurium matrix and a combined magnetic and electric interaction of iodine in nickel. The results are | Q (3 + )| = 0.23±0.07 b and Q (1 + ) = −0.170±0.006 b and μ (1 + ) = +1.88±0.11 μ N , confirming a [(π g 7 2 )(ν d 3 2 ) −1 ] and a [(π d 5 2 )(ν d 3 2 ) −1 ] configuration for the states concerned.

Comparative study of the sensitivity and specificity of the zinc and acid phosphatase spot tests for the detection of seminal stains

SummaryThe sensitivity and specificity of a zinc spot test for the detection of semen were compared with those of an acid phosphatase detection method. As screening techniques both tests were found to be very sensitive, but the zinc test was more specific and was more reliable in older and especially in deteriorated specimens. It is concluded that the zinc spot test deserves at least the same place as the acid phosphatase test in the primary investigation of suspected semen stains and might well be the test of choice in older and poorly preserved stains.ZusammenfassungSensitivität und Spezifität eines Fleckentests zum Spermanachweis auf der Basis der Zinkkonzentration im Samen wurden mit den genannten Gütekriterien der sauren Phosphatasetechnik verglichen. Beide Tests waren als Suchtests geeignet, aber der Zinktest erwies sich als spezifischer und zuverlässiger für ältere und denaturierte Proben. Demnach kommt dem Zinktest als Sperma-Suchtest zumindest derselbe Stellenwert zu, wie der Phosphatase-Methode. Bei alten und schlecht erhaltenen Spuren sollte dem Zinktest der Vorzug gegeben werden.

Bloodgroup simulating activity in aerobic gram-negative oral bacteria cultured from fresh corpses

The gram-negative aerobic oral bacterial flora of 100 consecutive corpses was isolated. After the identification and culturing of the isolated organisms, blood grouping was performed by the haemagglutination inhibition technique on dried culture smears, the dried culture medium and a dried ethanol extract of the bacteria. Forty-seven of the samples showed a gram-negative aerobic bacterial growth, giving 58 microorganisms of 14 different species. Positive blood grouping results were found in two of them (Escherichia coli and Serratia marcescens), both of type B. It is concluded that occasional mistyping of blood groups on saliva and oral material may be caused by the oral gram-negative aerobic flora, especially if the specimens are contaminated or putrefying.

Spin and parity assignment of the 1924 keV level in 131I

The spin and parity of the 1924 keV level in 131I are determined uniquely by angular correlation measurement of the 1151 keV-774 keV cascade and conversion coefficient measurement of the 278 keV transition to be 11/2-.

The angular correlation of the 459.7−27.7 kev γ-γ-cascade in129I and its use for a TDPAC

In contrast to earlier measurements, the angular correlation coefficient of the 459.7−27.7 keVγ-γ cascade in129I has been found to be consistent with the mixing ratios of the transitions and equal toA22=−0.0305±0.0037. Further, it is shown that this cascade can be used for time differential hyperfine interaction studies.