The life cycle of Hedruris spinigera Baylis, 1931 (Nematoda: Hedruridae) is determined here with the first formal identification of the parasite's intermediate host: the crustacean amphipod Paracorophium excavatum Thomson. Adult H. spinigera are redescribed from specimens collected from the stomach of fishes, Retropinna retropinna (Richardson) and Aldrichetta forsteri (Valenciennes), from Lake Waihola, New Zealand. Immature adults of the parasite collected from intermediate hosts (P. excavatum) are also described for the first time. The prevalence, abundance and intensity of infection of H. spinigera in several fish species are quantified along with the occurrence of P. excavatum, the parasite's intermediate host, in fish stomach contents. Although H. spinigera's transmission mode (trophic transmission) and fish diet potentially expose all fish species to infection, some level of host specificity must exist as parasite prevalence, abundance and intensity of infection vary greatly between potential definitive host species. We suggest here that the anatomy of the fish digestive tract and especially that of the stomach plays an important role in host suitability for H. spinigera. While P. excavatum is the only intermediate host in Lake Waihola, H. spinigera was found in six different fish species: Aldrichetta forsteri, Galaxias maculatus (Jenyns), Retropinna retropinna, Rhombosolea retiaria Hutton, Perca fluviatilis Linnaeus and Salmo trutta Linnaeus; although typical hedrurid attachment and mating positions were observed only in R. retropinna and A. forsteri. The limited distribution of H. spinigera is most likely due to that of its different host species (intermediate and definitive), all inhabitants of coastal fresh and brackish waters.
This paper is a continuation of Y. Liu, Anti-periodic solutions of nonlinear first order impulsive functional differential equations, Math. Slovaca 62 (2012), 695–720. By using Schaefer's fixed point theorem, new existence results on anti-periodic solutions of a class of nonlinear impulsive functional differential equations are established. The techniques to get the priori estimates of the possible solutions of the mentioned equations are different from those used in known papers. An example is given to illustrate the main theorems obtained. One sees easily that Example 3.1 can not be solved by Theorems 2.1–2.3 obtained in Liu's paper since (G2) in Theorem 2.1, (G4) in Theorem 2.2 and (G6) in Theorem 2.3 are not satisfied.
Using EPR spectroscopy it was found that CdCl2 and HgCl2 interact (1) with the intermediates Z./D., i.e. with the tyrosine radicals on the donor side of photosystem (PS) 2 situated in the 161st position in D1 and D2 proteins; (2) with the primary donor of PS1 (P700) whereby the oxidation of chlorophyll (Chl) a dimer in the reaction centre of PS1 occurs yet in the dark; (3) with the manganese cluster which is situated in the oxygen evolving complex. Due to these interactions of investigated metal chlorides with the photosynthetic apparatus, the interruption of the photosynthetic electron transport through photosynthetic centres occurs. Monitoring of time dependence of EPR signal I of chloroplasts treated with CdCl2 or HgCl2 after switching off the light suggests that all mechanisms, i.e. direct, cyclic, and non-cyclic reductions of P700+ are damaged. The formation of complexes between mercury or cadmium ions and amino acid residues constituting photosynthetic peptides was suggested as possible mechanism of their inhibitory action. The higher HgCl2 efficiency in comparison with that of CdCl2 was explained by higher ability of mercury ions to form complexes with amino acids, what was demonstrated by their apparent binding constants: K = 10 200 M-1 for Hg2+ ions, and K = 3 700 M-1 for Cd2+ ions. and F. Šršeň, K. Kráľová.
The article presents the results of geophysical prospection in the quadrangular enclosure of Markvartice, Jičín district, which was carried out in 2018. The obtained data resulted in new findings about the arrangement of internal buildings within sites of this kind known from the territory of Bohemia. The ascertained form of architectural arrangement of the internal space has exact analogies only in identical types of LT C2–D1 enclosures known from the territory of southern Germany. The questions of its particular form, classification possibilities and importance are discussed. The results also confirm the affiliation of the whole enclosure with La Tène sites, the so-called Viereckschanzen, which was repeatedly disputed in the past. and Článek prezentuje výsledky geofyzikální prospekce čtyřúhelníkového valového areálu v Markvarticích, okr. Jičín, jež byla realizována v roce 2018. Získaná data přinášejí nové poznatky o organizaci vnitřní zástavby těchto areálů známých z českého území. Zjištěná forma architektonického uspořádání vnitřního prostoru má dosud přesné analogie pouze u identických typů ohrazených areálů známých z období LT C2–D1 z oblasti jižního Německa. Otevřeny jsou tak otázky její konkrétní podoby, možností klasifikace i významu. Výsledky zároveň potvrzují příslušnost celého ohrazení k laténským areálům tzv. Viereckschanzen, o níž byla v minulosti opakovaně vedena diskuse.
Three new species, belonging to the newly proposed genus Pseudopicobia gen. n., inhabiting body quill feathers of puffbirds (Piciformes: Bucconidae), are described: P. nonnula sp. n. from Nonnula frontalis (Sclater) in Colombia, P. malacoptila sp. n. from Malacoptila panamensis Lafresnaye in Colombia and P. hapaloptila sp. n. from Hapaloptila castanea (Verreaux) in Ecuador. The new genus differs from morphologically similar genus Picobia Heller, 1878 by the absence of the genital setae, absence of the genital lobes, solenidia φI represented by microsetae, and by the presence of setiform solenidia σI. Syringophilid mites are recorded from birds of this family for the first time.
Bentholebouria colubrosa gen. n. et sp. n. (Digenea: Opecoelidae) is described in the wenchman, Pristipomoides aquilonaris (Goode et Bean), from the eastern Gulf of Mexico, and new combinations are proposed: Bentholebouria blatta (Bray et Justine, 2009) comb. n., Bentholebouria longisaccula (Yamaguti, 1970) comb. n., Bentholebouria rooseveltiae (Yamaguti, 1970) comb. n., and Bentholebouria ulaula (Yamaguti, 1970) comb. n. The new genus is morphologically similar to Neolebouria Gibson, 1976, but with a longer cirrus sac, entire testes, a rounded posterior margin with a cleft, and an apparent restriction to the deepwater snappers. Morphologically, the new species is closest to B. blatta from Pristipomoides argyrogrammicus (Valenciennes) off New Caledonia but can be differentiated by the nature of the internal seminal vesicle (2-6 turns or loops rather than constrictions), a longer internal seminal vesicle (occupying about 65% rather than 50% of the cirrus sac), a cirrus sac that extends further into the hindbody (averaging 136% rather than 103% of the distance from the posterior margin of the ventral sucker to the ovary), and a narrower body (27% rather than 35% mean width as % of body length). A Bayesian inference analysis of partial sequence of the 28S rDNA from Neolebouria lanceolata (Price, 1934), Cainocreadium lintoni (Siddiqi et Cable, 1960), Hamacreadium mutabile Linton, 1910, Opecoeloides fimbriatus (Linton, 1910), Podocotyloides brevis Andres et Overstreet, 2013, the new species, and previously published comparable sequences from 10 opecoelid species revealed two clades. One clade includes deep-sea (≥ 200 m) and freshwater fish opecoelids + Opecoeloides Bremser in Rudolphi, 1819, and a second clade included those opecoelids from shallow-water marine, perciform fishes.
Recently the Earth System Modelling Group of GeoForschungsZentrum (ESMGFZ) in Potsdam started producing a new series of Effective Angular Momentum Excitation Functions (EAM). As a novelty, the data is given in 3-hour resolution for the influence of the atmosphere and dynamic ocean, and 1-day resolution for terrestrial hydrosphere and barystatic sea-level changes. In addition to this, IERS recently started publishing their new series of C04 solution for Earth Orientation Parameters (EOP), based on new combination of all observations and ITRF2014 terrestrial frame. We use the ESMGFZ data to numerically integrate Brzeziński’s broad-band Liouville equations in celestial frame and compare the results with IERS C04 solution for celestial pole offsets in the interval 1986.0-2018.4. Alternatively, we also add a possible influence of unevenly distributed Geomagnetic jerks (GMJ). In the process of integration we look for the best-fitting parameters (period T, Q-factor) of Free Core Nutation (FCN). It is demonstrated that the fit between integrated and observed values is much better when compared with our previous solutions, based on older models of geophysical excitations. The fit is improved significantly when GMJ quasi-impulse effect is included. The best fit is obtained for atmospheric, oceanic and GMJ excitations, the preferred parameters of FCN being.. . We also estimate new value for empirical prograde MHB Sun-synchronous correction.
Due to changes at the Gabčíkovo Water Structure‘s Provisional Rules of Operation developed in 2011 at Slovenské elektrárne Inc. - Hydro power plants Trenčín enterprise, a new hydromodel for operating the Gabčíkovo Water Structure was implemented. This hydromodel is capable of planning and exploiting the regulatory functions of the Gabčíkovo Water Structure more effectively than it was previously. The new hydromodel additionally incorporates a simulating model of flow transformation downstream of the Gabčíkovo Water Structure, which will examine the substantiality of Gabčíkovo Water Structure projected operation for compliance with nautical parameters downstream the Gabčíkovo Water Structure. and Obsahuje seznam literatury
Bone metabolism is regulated by interaction between two skeletal cells – osteoclasts and osteoblasts. Function of these cells is controlled by a number of humoral factors, including neurohormones, which ensure equilibrium between bone resorption and bone formation. Influence of neurohormones on bone metabolism is often bimodal and depends on the tissue, in which the hormone is expressed. While hypothalamic beta-1 and beta-2-adrenergic systems stimulate bone formation, beta-2 receptors in bone tissue activate osteoclatogenesis and increases bone resorption. Chronic stimulation of peripheral beta-2 receptors is known to quicken bone loss and alter the mechanical quality of the skeleton. This is supported by the observation of a low incidence of hip fractures in patients treated with betablockers. A bimodal osteo-tropic effect has also been observed with serotonin. While serotonin synthetized in brain has osteo-anabolic effects, serotonin released from the duodenum inhibits osteoblast activity and decreases bone formation. On the other hand, both cannabinoid systems (CB1 receptors in the brain and CB2 in bone tissue) are unambiguously osteoprotective, especially with regard to the aging skeleton. Positive (protective) effects on bone have also been shown by some hypophyseal hormones, such as thyrotropin (which inhibits bone resorption) and adrenocorticotropic hormone and oxytocin, both of which stimulate bone formation. Low oxytocin levels have been shown to potentiate bone loss induced by hypoestrinism in postmenopausal women, as well as in girls with mental anorexia. In addition to reviewing neurohormones with anabolic effects, this article also reviews neurohormones with unambiguously catabolic effects on the skeleton, such as neuropeptide Y and neuromedin U. An important aim of research in this field is the synthesis of new molecules that can stimulate osteo-anabolic or inhibiting osteo-catabolic processes., I. Žofková, P. Matucha., and Obsahuje bibliografii