From November 1997 to June 1998, 3,118 specimens of Echinogammarus stammeri (Karaman, 1931) (Amphipoda) were collected from the River Brenta (Northern Italy) and examined for larval helminths. Larvae of Polymorphus minuius (Goeze, 1782) singly infected the hemocoel of 23 (0.74%) crustaceans; all these larvae were cystacanth stages. This is the first record of Polymorphus minuius in E. stammeri. Some cystacanths had their forebody and hindbody fully inverted. Parasites were bright orange in colour and each was surrounded by a thin acellular envelope. This envelope likely protects the developing parasite larva from cellular responses of the amphipod. Hemocytes were seen adherent to the outer surface of the envelope. The sex ratio among the parasitised E. stammeri was almost 1:1. All Polymorphus minutus larvae were central in the amphipod body, made intimate contact with host internal organs, and frequently induced a marked displacement of them. None of the infected females of E. stammeri. carried eggs or juveniles in their brood pouch. In five hosts, Polymorphus minuius co-occurrcd with the cystacanth of another acanlhocephalan, Pomphorhynchus laevis (Millier, 1776), a parasite offish.
The object of the research was to investigate the spectral properties of Rayleigh-type surface waves, generated by shot-hole explosions during seismic refraction experiments which were carried out in the area of the Bohemian Massif and West Carpathians. The records of displacement amplitudes were spectrally analyzed and prevailing frequency fp, relative Δfr and absolute widths of the spectra Δfa were chosen as essential parameters. Whilst the prevailing frequencies were recorded within the interval f ÷ 0.80 - 3.70 Hz at the site of the observations, situated on the territory of the Bohemian Massif, the respecti ve frequency range f ÷ 0.80 - 2.6 Hz was found in the West Carpathians. Some functional dependences of the spectral amplitude parameters on epicentral distance were observed and regularities of their decrease were defined. Moreover, the influence of local seismogeological conditions at the shot point as well as at the site of observation occurred., Karel Holub., and Obsahuje bibliografické odkazy
This article is focused on the surface assessment of some ground glasses grinded by means different sorts of abrasion dust. It determines amplitude roughness parameters of ground glass samples and related PSD functions. Measurements were done by means of mechanical inductive profilometer Form Talysurf Series 2 - both software and hardware gear for solid surface assessment of shape, waviness and roughness with extraordinary resolution. and Článek je zaměřen na zhodnocení stavu povrchu několika matnic vybroušených různými brusivy stanovením amplitudových parametrů drsnosti a PSD funkcí. Měření probíhala na přístroji Form Talysurf Series 2. Jedná se o indukční mechanický profilometr - hardwarový i softwarový nástroj pro detekci parametrů tvaru, vlnitosti a drsnosti povrchů pevných těles s mimořádnou rozlišovací schopností.