The study focuses on the early medieval large glass beads from the area of Poland, i.e. specimens whose diameter equals at least 1.5 cm but usually ca. 2 cm or more. The main aim of this study is to define their function, considering precise context of discovery of particular specimens, metric data and microscopic analyses. Another important task of the study is to determine whether large beads were local products or imports, and from which region and in what social circumstances they reached the studied area. Alongside macroscopic and stylistic features, chemical composition of glass that was used for production of the beads can be conclusive in this situation. In our opinion, it is a special category of finds that appeared in this part of Europe during the time of cultural and political transformation in the 11th–13th centuries. and Předmětem studie jsou polské nálezy raně středověkých velkých skleněných korálů, tj. exemplářů, jejichž průměr činí nejméně 1,5 cm, ale obvykle kolem 2 cm či více. Hlavním cílem je přispět k objasnění jejich funkce na základě nálezového kontextu, metriky a výsledků mikroskopické analýzy. Neméně důležité jsou otázky, zda se jedná o místní produkci či o importy, jaká je jejich geografická distribuce a sociální charakteristika prostředí, ve kterém byly nalezeny. Kromě makroskopicky patrných a morfologických znaků autorky hodnotí též chemické složení korálů. Docházejí k závěru, že velké korály reprezentují samostatnou kategorii nálezů a jejich výskyt odráží kulturní a politické proměny středoevropské společnosti v 11.–13. století.
Renal sympathetic hyperactivity is critically involved in hypertension pathophysiology; renal denervation (RDN) presents a novel strategy for treatment of resistant hypertension cases. This study assessed effects of two RDN systems to detect acute intravascular, vascular and peri-vascular changes in the renal artery, and renal nerve alterations, in the sheep. The procedures using a single-point or multi-point ablation catheters, Symplicity FlexTM, Medtronic versus EnligHTNTM, St. Jude Medical were compared; the intact contralateral kidneys served as controls. Histopathological and immunohistochemical assessments were performed 48 h after RDN procedures; the kidney and suprarenal gland morphology was also evaluated. Special staining methods were applied for histologic analysis, to adequately score the injury of renal artery and adjacent renal nerves. These were more pronounced in the animals treated with the multi-point compared with the single-point catheter. However, neither RDN procedure led to complete renal nerve ablation. Forty-eight hours after the procedure no significant changes in plasma and renal tissue catecholamines were detected. The morphologic changes elicited by application of both RDN systems appeared to be dependent on individual anatomical variability of renal nerves in the sheep. Similar variability in humans may limit the therapeutic effectiveness of RDN procedures used in patients with resistant hypertension., M. Táborský, D. Richter, Z. Tonar, T. Kubíková, A. Herman, J. Peregrin, L. Červenková, Z. Husková, L. Kopkan., and Obsahuje bibliografii
This study used an experimental early rehabilitation model combining an enriched environment, multisensory (visual, acoustic and olfactory) stimulation and motor training after traumatic brain injury (via fluid-percussion model) to simulate early multisensory rehabilitation. This therapy will be used by brain injured patients to improve neural plasticity and to restore brain integration functions. Motor dysfunction was evaluated using a composite neuroscore test. Direct structural effects of traumatic brain injury were examined using Fluoro-Jade staining, which allows identification of degenerating neural cell bodies and processes. Animals in the rehabilitation model group performed significantly better when tested for neuromotor function than the animals in standard housing in the 7-day and 15-day interval after injury (7d: p=0.005; 15d: p<0.05). Statistical analysis revealed significantly lower numbers of Fluoro-Jade positive cells (degenerating neurons) in the rehabilitation model group (n=5: mean 13.4) compared to the standard housing group (n=6: mean 123.8) (p<0.005). It appears that the housing of animals in the rehabilitation model led to a clear functional increase in neuromotor functions and to reduced neural loss compared with the animal group in standard housing., M. Lippert-Grüner. M. Maegele, J. Pokorný, D. N. Angelov, O. Švestková, M. Wittner, S. Trojan., and Obsahuje bibliografii a bibliografické odkazy
In the xantha1 (xan1) mutant of sunflower (Helianthus annuus L.), the effects on organ anatomy and seedling growth did correlate to the alteration of chloroplast biogenesis. The xan1 seedlings grown under 165 µmol(photon) m-2 s-1 revealed a severely altered chloroplast ultrastructure in cotyledons and leaves. Cross-sections or clarified tissues of the xan1 cotyledons did not show evident alterations with respect to normal cotyledons suggesting that the impairment of chloroplast biogenesis has negligible consequences on embryonic leaves. By contrast, the analysis of xan1 leaves showed that the defects in chloroplast biogenesis were correlated to a drastic reduction of organ size and to a clear enhancement of the trichome growth. The differentiation of palisade and spongy parenchyma in cotyledons and leaves of the xan1 mutant was normal but both organs displayed a drastic reduction in the plastid number with respect to wild type. In addition, xan1 hypocotyls showed a reduced development of the main vascular bundles in comparison with normal seedlings and an undersized central cylinder of the primary root. The exogenous supply of sucrose was not sufficient to revert in vitro the deficit of xan1 growth and the constraints in morphogenetic processes. and M. Fambrini ... [et al.].
Different aspects of star formatlon are discussed on the basis of new submm observations. In NGC2024 slx cold (T-16K) and dense (nH“lE8-lE9cm^-3) so far unknown condensations are found and interpreted as isothermal protostars. The density and temperature structure around massive early type stars which are deeply embedded in dense regions is discussed by means of thermai
emission from dust. A star formation efficiency of 8% is derived from 90 compact HII regions. A comparison with the star formation in normal spiral galaxles and active Markarlan objects leads to a
new deflnltion of actlvity. The L/M ratlo of active sytems is by a factor of 20 higher than the corresponding value in normal splrals and galactic HII regions.
The very young LMC clusters SL666, NGC2098 and NGC2100 were found to exhibit a variation of spectral types with distance from the cluster centre. From spectral dassification of their bright members it is found that the early type stars are accumulated in the inner region of the cluster whereas the late type ones are found in the outer areas. Star counts on photographic plates with different exposure times have shown that the bright stars are segregated in the central regions of the clusters. Both observational results from spectral classlfication and star counts give evidence that the most massive early type stars are located in the inner parts of the clusters. This allow us to suggest that the observed mass segregation is not due
to the relaxation mechanism of the clusters.
The long water-tube tiltmeter observations of the plumb line variations were begun about four years ago. Since 2001, twice, the instrument registered strong plumb line variations associated with earthquake. Earthquake in September 2003 made opportunity for verification of hydrodynamic system of tiltmeter. We obtained in observations large number of cycle-slip effects, which made impossible correct interpretation of data during main phase of phenomenon. Results of tests of dumping system of water waving helped us to introduce some improvements in hydrodynamic system of instrument. Catastrophic earthquake with magnitude 9.1 which took place in the area of Indian Ocean on 26th December 2004 generated phenomenon of the Earth free oscillations associated with anomalous plumb line variations of the order of single milliseconds of arc (mas). The effects of surface waves passing associated with Earth free oscillations were registered by the tiltmeter as series of anomalous plumb line variations. Surface waves produced several milliseconds of arc amplitude of plumb line variations. Results of observations showed that low-pass filters considerably reduce contribution of short-period effects and effectively protect hydrodynamic system of instrument against resonance. Nevertheless during first two hours of phenomenon cycle-slip effects occurred several times. Plot of plumb line variations in space from 26th December 2004 showed us large complication of tilt signals as well as dominated role of tidal signal. Spectral analysis of the time series of the plumb line variations obtained with help of the long water-tube tiltmeter on 26 December 2004 appeared existing fundamental modes (n = 0) in the Earth free oscillations didn’t exceed 0.2 mas., Marek Kaczorowski., and Obsahuje bibliografii
The orientation of the Earth in space is measured by space geodetic techniques. Each technique has its weaknesses so the best way how to get a representative solution of Earth orientation parameters is to combine all of them together using some appropriate method. There are basically two approaches, the rigorous and non-rigorous one. The method used in this paper belongs to the second category. Since 1999, when the authors Kostelecký and Pešek put basis of the combination method, the method has been modified and improved. The particular improvements are described hereafter and recent results are presented. These results of collocation station velocities are compared with the velocities published by ITRF 2005 and NUVEL-1A. The mean values of differences are 2.7 mm/y and 5.9 mm/y, respectively., Vojtěch Štefka, Ivan Pešek, Jan Vondrák and Jan Kostelecký., and Obsahuje bibliografii
Recently we derived a new star catalog EOC-4 that contains not only the mean positions and linear proper motions, but also periodic changes, due to orbital motions, for double and multiple star systems. The catalog contains 4418 stars that were observed in programs monitoring Earth orientation by optical astrometry during the 20th century. 599 stars of the catalog have significant periodic components. This catalog is now used, as a basic celestial frame, to obtain the Earth orientation parameters from optical astrometric observations of latitude/universal time/altitude in the interval 1899.7-1992.0. Polar motion is determined in 5-day steps for the whole interval studied, Universal time covers the interval 1956.0-1992.0 (i.e., after the invention of atomic clocks) also in 5-day steps, and celestial pole offsets (with respect to recent IAU2000 and IAU2006 models of nutation and precession) are modeled by second-order polynomials of time. In addition to these, a combination of Love and Shida numbers for each observing site is computed., Jan Vondrák, Cyril Ron and Vojtěch Štefka., and Obsahuje bibliografii