Ninety four aquarium fishes were screened for the presence of amoebae in their internal organs. Five specimens of Ca-rassius auratus (L.) and one specimen of Xiphophorus hetleri Heckel were positive. Of the three strains which were isolated from C. auratus, successfully cloned and cultivated, one was identified as Vannella platypodia (Gläser, 1912) Page, 1976 and two strains as Rosculus ithacus Hawes, 1963. Both species are reported for the first time from organs of fish. None of them could be identified with the amoeba-like agent of goldfish granulomas described here.
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
In this paper, a hybrid regularizers model for Poissonian image restoration is introduced. We study existence and uniqueness of minimizer for this model. To solve the resulting minimization problem, we employ the alternating minimization method with rigorous convergence guarantee. Numerical results demonstrate the efficiency and stability of the proposed method for suppressing Poisson noise.
Over a 7-year period, parasites have been collected from 28 species of groupers (Serranidae, Epinephelinae) in the waters off New Caledonia. Host-parasite and parasite-host lists are provided, with a total of 337 host-parasite combinations, including 146 parasite identifications at the species level. Results are included for isopods (5 species), copepods (19), monogeneans (56), digeneans (28), cestodes (12), and nematodes (12). When results are restricted to those 14 fish species for which more than five specimens were examined and to parasites identified at the species level, 109 host-parasite combinations were recorded, with 63 different species, of which monogeneans account for half (32 species), and an average of 4.5 parasite species per fish species. Digenean records were compared for 16 fish species shared with the study of Cribb et al. (2002); based on a total of 90 parasite records identified at the species level, New Caledonia has 17 new records and only seven species were already known from other locations. We hypothesize that the present results represent only a small part of the actual biodiversity, and we predict a biodiversity of 10 different parasite species and 30 host-parasite combinations per serranid. A comparison with a study on Heron Island (Queensland, Australia) by Lester and Sewell (1989) was attempted: of the four species of fish in common and in a total of 91 host-parasite combinations, only six parasites identified at the species level were shared. This suggests strongly that insufficient sampling impairs proper biogeographical or ecological comparisons. Probably only 3% of the parasite species of coral reef fish are already known in New Caledonia.
Cortical epileptic foci elicited by local application of bicuculline methiodide represent a model of interictal epileptic activity with a transition into ictal phases. We studied a role of GABA-B receptors in this model using GABA-B receptor antagonist CGP35348 in adult rats with implanted cortical electrodes and cannula. CGP35348 (100 or 200 mg/kg i.p.) did not affect interictal discharges but it augmented ictal activity. Latency to the first ictal episode was decreased by the lower dose of CGP35348, duration of episodes was increased by the higher dose. GABA-B receptor antagonist did not influence purely cortical epileptic phenomenon but it is proconvulsant in ictal activity generated with participation of subcortical structures., P. Mareš, K Bernášková, H. Kubová., and Obsahuje seznam literatury
This paper presents an adroit utilization of dimensional analysis-based model theory by which the deformation of a structure - however complex - can be elegantly and easily obtained. The structure is loaded by a concentrated lateral load of arbitrary location and magnitude. The relevant technique is outlined in some details; therefore the reader is advised to follow the presented routine closely. By doing so, he will be impressed by the prowees and economy of the described process. In the Preamble, the more important relevant theorems and relations - without proofs - are given in greatly condensed forms. This summary will help the reader to understand the subsequent application presented. Full treatment of the theories and practice of applied dimensional model theory can be found in [1], which the interested and motivated reader is advised to consult. and Obsahuje seznam literatury
Habitat degradation is a major threat to the survival of chiru (Pantholops hodgsonii). Detailed knowledge for habitat conservation in this steppe-dwelling ungulate is needed if effective conservation and management strategies are to be developed. The distribution of potential habitat and the relative value of habitat to chiru on a regional scale remains unknown, hindering landscape conservation planning. Our aim was to identify and rank chiru habitat across the Chang Tang region of the Tibetan Plateau. We assessed overall habitat suitability using geographical data, field surveys, and information contained within previous studies. We identified 10194 km2 of optimal habitat (1.71 % of the region), 256816 km2 of suitable habitat (43.17 % of the region), and 213799 km2 of marginal habitat (35.94 % of the region). Our habitat model shows that suitable habitat is located primarily in the central (Nyingma county and Shuanghu county) and western (Geze county) regions of the study area. When we looked specifically at a chiru reserve (Chang Tang Nature Reserve) located within the study area, we found that over half of the reserve could be classified as suitable habitat. This highlights the regional importance of this reserve to chiru conservation. Our findings further indicate that the protection of suitable habitat and improvement of habitat linkages will be important features of any regional chiru conservation plan.