Role of computed tomography in the estimation of the density of the bony block of an injured vertebral column segment at different stages of treatment with an external transpedicular fixation apparatus

A Somatom AR.HP computed tomograph (Siemens) was used to make studies in 54 patients with injury to the vertebral column and spinal cord in order to determine the formation of a bony block and its density in different portions of an injured segment at the stages of treatment. During therapy, the highest values of bony block density were observed in the dorsal portions of an injured segment (mean 377.32 +/- 184.57 HU). This may be accounted for by a slight effect of artefacts of an external transpedicular fixation apparatus, the main components of which are present at the posterior supporting complex. After treatment, the highest values of bony block density were noted in the central portions of an injured segment (mean 353.11 +/- 208.01 HU). This may be associated with rather serious intervertebral disk damage in this portion. The bony block density index was 339.75 +/- 139.41 HU in the left lateral portions and as high as 312.56 +/- 135.07 HU in the right ones. In the late period, the highest bony block density index (mean 397 +/- 193.07 HU) was seen in the right portions of an injured segment, which may be due to slight scoliotic deformity with the angle being open to the right.     

Effect of Invasive Species of Herbaceous Plants and Associated Aphids (Hemiptera,Sternorrhyncha: Aphididae) on the Structure of Ant Assemblages (Hymenoptera,Formicidae)

—In 2015–2017, attendance of 15 invasive and 22 native species of herbaceous plants by ants was studied in 6 habitats in the environs of Kyiv (Ukraine). Altogether, 14 ant species were found, of which 12 were recorded on invasive plants and 9 on native plants; 8 aphid species were found on 8 invasive plant species. Five invasive plant species (Asclepias syriaca, Heracleum mantegazzianum, Oenothera biennis, Onopordum acanthium, and Amaranthus retroflexus) were found to be attractive to ants, with over a half of all the ant workers in all the habitats being recorded on them; besides, numerous colonies of 7 aphid species were also found on these plants. These invasive plants positively affect the structure of ant assemblages since the aphid colonies provide ants with food resource. The remaining 10 invasive plant species, including 5 transformer species, were poorly visited by ants and housed no aphid colonies, with the exception of Conyza canadensis on which the non-myrmecophilous aphid Uroleucon erigeronense (Thomas, 1878) was found. Two thirds of invasive plant species had a negative effect on the structure of ant assemblages because they replaced the native plants and thus reduced the trophic resources of aphids.

     

Ants (Hymenoptera,Formicidae) of Kyiv

Entomological Review - Altogether, 59 ant species from 22 genera of 4 subfamilies have been recorded in Kyiv. Four of them are occasionally introduced species which occur only in premises heated in...