Fast Ecotoxicity Detection Using Biosensors

The article provides information about a new device, AlgaTox developed in the R&D project sponsored by the Technology Agency (n.TA02030179) and patented in Czech Republic (CZ 305687). Its functionality is based on the use of biosensor, and its main advantage is fast response rate. The toxicity detection is achieved through precise measurement of green algae oxygen production dynamics after their exposure to light of wavelength of 680 nm. Clark sensor with a resolution of 0.05% of the equilibrium oxygen concentrations and stability at a constant pressure and temperature of 0.1% of the equilibrium oxygen concentration at the 24-h measurement is used for the oxygen detection. Laboratory testing of the device has been made using silver nitrate, substance with known inhibitory effect on algae. Real samples of aqueous soil extracts and waste sample from old dried-up industrial tailing pond enriched with insecticide have been also tested. The values of oxygen production inhibition or stimulation determined with the new device in the evaluation of real samples were up to six times higher in comparison with the corresponding values of inhibition (stimulation) of growth rates determined by standard procedure.     

Occurrence of ixodid ticks--the main vectors of tick-borne encephalitis virus in urbanized territory

The influence of urbanization on ticks I. ricinus and I. persulcatus--the main vectors of tick-borne encephalitis virus is discussed on the basis of concrete examples. It has been revealed that under favourable conditions the populations of these tick species can exist for a long time not only in towns and new housing estates, but in the old residential districts as well. The necessity of studying the ecology of urban populations of ixodid ticks is pointed out.     

Occurrence of the tick Ixodes ricinus (L.) under the conditions of anthropopressure

The authors report on their findings of the tick Ixodes ricinus under urban conditions of Prague. The concrete data were taken as a basis for a general scheme of possible occurrence of this species in various town parts, determined by the state of vegetation and presence of large mammals. Discussed are also conditions for I. ricinus maintenance in another type of anthropogenous landscape, the spoil banks resulting from brown coal exploitation.     

The feather mites of the family Proctophyllodidae (acari, sarcoptiformes) from Nepalese birds

Eight species of birds of the families Fringillidae (3), Motacillidae (2), Prunellidae (1), Pycnonotidae (1) and Turdidae (1) were found to be parasitized by 8 species of the genus Proctophyllodes, 3 of them being new to science: P. danieli sp. n. from Pycnonotus leucogenys, P. macrophallus sp. n. from Prunella collaris and P. puniceus sp. n. from Pyrrhospiza punicea. Other species recorded are P. anthi, P. cotyledon, P. glandarinus, P. leucosticti and P. aff. poublani. All hosts were collected in the region of the Barun river valley in East Nepal in the altitude of 3,600-4,900 m a. s. l.     

Ticks of small mammals from the Hindu Kush (Afghanistan).

During the First Czechoslovak expedition to the East Hindu Kush in June-September 1965 a total of 193 hosts belonging to 12 species was examined on the presence of ticks. Specimens of the genera Ixodes, Haemaphysalis, Dermacentor and Rhipicephalus were found. Data and comments are given for the species collected.     

Mapping tree root systems with ground-penetrating radar

A ground-penetrating radar (GPR) technique was used to study the three-dimensional distribution of root systems of large (DBH = 14 to 35 cm) oak trees (Quercus petraea (Mattusch.) Liebl.) in relatively dry, luvisoil on loamy deluvium and weathered granodiorite. We used a pulse EKKO 1000 GPR system, a profile grid of 0.25 x 0.25 meters, at 0.05 m intervals, and a signal frequency of 450 MHz, to assure resolution of about 3 cm in both directions (further increases in resolution up to 1 cm are possible with the system). Coarse root density was 6.5 m m(-2) of stand area and 3.3 m m(-3) of soil volume. Maximum rooting depth of the experimental oaks was 2 m, and the root ground plan was significantly larger (about 1.5 times) than the crown ground plan. Based on earlier studies of Quercus robur L. from floodplain forests, where the extent of the root systems was much smaller (root ground plan:crown ground plan ratio of 0.6), we conclude that the high root ground plan:crown ground plan ratio indicates less favorable conditions of water supply at the experimental site than in the floodplain forest. The ground-penetrating radar system is noninvasive and allows relatively rapid and repeated measurements of the distribution of coarse root systems of trees.     

Cross-reactive anti-human monoclonal antibodies as a tool for B-cell identification in dogs and pigs

We have characterized a panel of commercially available anti-human monoclonal antibodies (mAbs) suitable for B-cell identification in pigs and dogs. The specificities of the mAbs were against CD20, CD21, CD22, and CD86. In addition to HM57, originally raised against human CD79alpha the broad cross-reactivity of which was documented more than 10 years ago, we recommend here a panel of several other mAbs as a useful tool for immunophenotyping and multicolor flow cytometry of canine and porcine B-lymphocytes. All six investigated antibodies did bind weakly to either canine or porcine lymphocytes (or both), but considerable weaker than for the human control cells. Four of them did bind to canine or porcine spleen section in immunohistochemistry. Monoclonal antibody against CD22 (clone RFB-4) was the only antibody in the tested panel the cross-reactivity of which was confirmed by Western blot. The advantages and limits of cross-reactive mAbs in studies on animal B-cells are discussed.