This is a followup report on the viability of pathogenic Acanthamoeba castellami, Naegleria australiensis, and N. fowleri during 5 years of cryopreservation and the virulence of N. fowleri during 30 months of cryostorage, all at -70’C. The greatest decrease in viability occurred during the first year of freezing and was 10-fold greater than the average yearly decrease during years 2-5. At 5 years of cryostorage, viability was 33 % for A. castellana, 38 % for N. fowleri and 51% for N. australiensis. Virulence of N. fowleri did not decrease during 30 months of freezing and what appeared to be an increase in virulence during cryopreservation may be the result of reduced viability of the less virulent amebae in a culture.
This is a follow-up report on the viability of pathogenic Naegleria fowleri, Naegleria australiensis and Acanthamoeba castellanii isolates during 5 to 10 years of cryopreservation at –70°C. The greatest decrease in viability occurred with N. fowleri and the least occurred with N. australiensis. At 10 years of cryostorage, viability was 21% for N. fowleri, 32% for A. castellanii and 51% for N. australiensis.
The influence of water environment on natural frequencies of a Francis pump-turbine runner with the shaft is analyzed. The computations are executed by ANSYS program package based on finite element method. The fluid ‘equivalent mass‘ matrix concept is used. For solution, the Euler approach is used. Obtained natural frequencies and vibration mode shapes of the turbine runner with shaft in vaccum, in air and in water are presented. Computed natural frequencies and vibration mode shapes of the turbine runner with shaft in vacuum are compared to computed natural frequencies and vibration mode shapes of the turbine runner without shaft. and Obsahuje seznam literatury
A detailed analysis of dynamical properties of five-blade-bundle mathematical model was carried out with the aim to investigate how the damping elements made of rubber inserted into slots between blades heads influence the response curves at different distribution of exciting harmonic forces. Viscous-elastic linear Voigt-Kelvin model was used for modeling the rheological properties of damping elements. Constant values of stiffness and damping parameters were supposed at analysis. The orthogonality of excitation forces distribution to the other eigenmodes of blades bundle is applied at insulated selected resonance. and Obsahuje seznam literatury
Caterpillars of the poplar lutestring moth, Tethea or, construct leaf shelters that they defend against intruding conspecifics using a combination of vibratory signals and physical aggression. Staged interactions between a resident caterpillar and introduced conspecific were recorded with a video camera and laser vibrometer. Residents crawl towards the intruder and perform three behaviours: lateral hitting, pushing, and mandible scraping. Vibrations caused by mandible scraping result from the caterpillar repeatedly scraping opened mandibles laterally against the leaf surface in bouts lasting 1.16 ± 0.39 s, with an average of 4 ± 1 scrapes per bout. We propose that these scrapes function in leaf shelter defense against conspecifics for the following reasons: Mandible scrapes are produced only by residents; they are generated when a resident is approached by an intruder; the rate of scraping increases as the intruder approaches the shelter; and residents in all trials retain their shelters, with the intruder leaving the leaf within 127.9 ±104.3s from the beginning of the trial. The function and evolutionary origins of vibration-mediated territoriality in caterpillars are discussed. and Jaclyn L. Scott, Jayne E. Yack.
In the paper there are deduced differential equations of the vibroisolation system of the ambulance couch. The kinematic excitation is realized in three directions: the vertical translation and the rotations around the both horizontal axes of the car. The suspension of the ambulance couch corresponds to this presumption and is made by the parallelogram; on the upper base there is a double level Cardan suspension.
The linearised system of the motion equations is stated and the preliminary analysis of the dependency of all the three natural frequencies on the selected parameters is made. By vertical kinematics excitation numerical simulation of the excited oscillations is made. and Obsahuje seznam literatury
Příspěvek se zabývá vícečetným pohřebním kontextem z Velkých Přílep (okr. Praha–západ), datovaným do starší doby bronzové. Studium je založeno na mezioborové spolupráci archeologie a biologické antropologie se zaměřením na teoretické otázky spojené s minulou živou kulturou (intencionalita, vznik a účel pohřebního komplexu) a její transformací do archeologických pramenů. Studium transformací formálních (poškození, rozpad a zánik kostní tkáně), polohových (disartikulace kostí v kloubních spojeních) a odhady některých antropologických parametrů bylo uskutečněno již v terénní fázi výzkumu. Diskutována jsou témata intencionality pohřebního kontextu, rekonstrukce postupu jeho ztvárnění a účelu v daném kulturním prostředí. and The work focuses on the context of a multiple burial of 6 individuals from Velké Přílepy (distr. Prague-west), dated to the Early Bronze Age. The study is based on the interdisciplinary cooperation between archaeology and biological anthropology, focusing on the theoretical issues linked to a past living culture (intentionality, rise and purpose of burial complex) and its transformation into archaeological record. The study of the transformation of formal (damage, decomposition and disintegration of bone tissue), positional (disarticulation of bone joints) and estimation of some anthropological parameters has already taken place during the fieldwork. Topics such as the intentionality of the rise of the burial complex, the reconstruction of the advancement of its formation and the purpose within the given cultural environment will be covered.