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
Commercial chambers for in vivo gas exchange are usually designed to measure on vascular plants, but not on cryptogams and other organisms forming biological soil crusts (BSCs). We have therefore designed two versions of a chamber with different volumes for determining CO2 exchange with a portable photosynthesis system, for three main purposes: (1) to measure in situ CO2 exchange on soils covered by BSCs with minimal physical and microenvironmental disturbance; (2) to acquire CO2-exchange measurements comparable with the most widely employed systems and methodologies; and (3) to monitor CO2 exchange over time. Different configurations were tested in the two versions of the chamber and fluxes were compared to those measured by four reference commercial chambers: three attached to two respirometers, and a conifer chamber attached to a portable photosynthesis system. Most comparisons were done on biologically crusted soil samples. When using devices in a closed system, fluxes were higher and the relationships to the reference chambers were weaker. Nevertheless, high correlations between our chamber operating in open system and measurements of commercial respiration and photosynthetic chambers were found in all cases (R2 > 0.9), indicating the suitability of the chamber designed for in situ measurements of CO2 gas exchange on BSCs., M. Ladrón De Guevara, R. Lázaro, J. L. Quero, S. Chamizo, F. Domingo., and Obsahuje bibliografii
a1_Diabetes mellitus is a risk factor of cardiovascular diseases. ECG of patients with diabetes mellitus type 1 (DM 1) shows tachycardia (block of parasympathetic innervation) and abnormal repolarization (increased QT interval and QT dispersion (QTd)) indicating a risk of ventricular tachycardia and sudden death in young people with DM 1. The aim of the present report was to measure 145 parameters of the heart electric field in 22 patients (14 men, 8 women) with DM 1 without complications (mean age 32.8±11.4 years) and in 22 controls (11 men, 11 women, mean age 30.1±3.4 years). The duration of diabetes was 13.9 ±7.8 years. The parameters were regist ered by the diagnostic system Cardiag 112.2 and statistically evaluated by the Student and Mann-Whitney test. Tachycardia (86.3±2.7 beats.min-1), shortening of both QRS (79.9±1.6 ms) and QT (349.0±5.9 ms) and increased QT dispersion (115±36 ms) were observed in DM 1 when compared with the controls (75.0±2.1 beats. min -1, QRS 89.9±2.7 ms, QT 374.0±4.4 ms, QTd 34.0±12.0 ms, p<0.01). The QTc was 415.2±4.1 ms in DM 1 and 401.4±6.6 ms in controls (NS)., a2_Other significant findings in DM 1 were: higher maximum of depolarization isopotential maps (DIPMmax) in the initial phase of QRS and less positive in the terminal phase, more negative minimum (DIPMmin) during QRS similarly as the minimum in depolarization isointegral maps (DIIMmin) and the minimum in isointegral map of the Q wave (Q-IIMmin), lower maximum in repolarization isopotential maps (RIPMmax) and less negative minimum (RIPMmin), more negative amplitude of Q wave (Q-IPMAM) and more pronounced spread of depolarization (activation time). Our results confirmed a decreased parasympathetic to sympathetic tone ratio (tachycardia, shortening of the activation time) and revealed different depolarization and repolarization patterns in DM 1. The differences in heart electric field parameters measured by the BSPM method in DM 1 and in the controls indicate the importance of ECG examination of diabetic patients type 1 in the prevention of cardiovascular diseases., D. Žďárská, P. Pelíšková, J. Charvát, J. Slavíček, M. Mlček, E. Medová, O. Kittnar., and Obsahuje bibiografii a bibliografické odkazy
Women with gestational diabetes mellitus (GDM) are at increased risk for cardiovascular diseases (CVD) events compared with women without GDM. The aim of the present study was to evaluate 200 parameters of the heart electric field in 35 women with GDM under optimal glycemic compensation compared to 32 healthy pregnant women. All examinations were performed in the 36th week of gestation. The parameters in ECG body surface mapping (BSM) were registered by the diagnostic system Cardiag 112.2. The absolute values of maximum and minimum in depolarization and repolarization isopotential, isointegral and isoarea maps were not significantly different between the groups. These findings correspond to the result of heart rate variability examination. However BSM revealed the significant prolongation of QRS complex (p=0.05), shortening of ventricular myocardial activation time (ICHVAT) (p=0.01), prolongation of mean QT duration (p=0.01) and increase of QT interval dispersion (p=0.01) in women with GDM. Duration of QRS and ICHVAT significantly correlated with interventricular septum and posterior wall thickness in GDM group, QTd interval correlated significantly with HbA1C level. We conclude that despite of optimal metabolic control several significant abnormalities detected by ECG BSM are still present in patients with GDM., E. Žákovičová, O. Kittnar, J. Slavíček, E. Medová, P. Šváb, J. Charvát., and Obsahuje bibliografii
Collections of ‘Echinorhynchus salmonis’ from Britain and Ireland deposited in The Natural History Museum, London (1921.7.19.3–12 and 1952.10.30.122–127) were reidentified as Acanthocephalus clavula and Acanthocephalus lucii respectively. The amphipod, Pontoporeia affinis, European intermediate host of E. salmonis, does not occur in the British Isles, so it is concluded that E. salmonis is absent from British and Irish freshwater fishes.
Rejskovití hmyzožravci (čeleď Soricidae) jsou drobní savci, kterých si v přírodě často sotva všimneme. Vyznačují se však mnoha zajímavostmi, díky kterým rozhodně stojí za naši pozornost. K těmto zajímavostem lze zařadit i schopnost echolokace, tj. schopnost orientovat se v prostoru za pomoci ozvěn cvakání, které vydávají. Kromě cvakání se během pohybu prostředím patrně orientují i pomocí štěbetavých hlasů. Bělozubky hnědé (Suncus murinus) při pohybu v neznámém prostředí také „duní“. Zda se i toto dunění uplatňuje při orientaci v prostoru není zatím jasné. Bělozubky pouštní (Diplomesodon pulchellum) zase při přechodu mezi různými typy substrátu vibrují, a tyto vibrace vytvářené celým tělem jim pravděpodobně pomáhají odhadnout vlastnosti substrátu a vyhnout se tak zbytečnému hrabání v hustém písku., Shrews (Soricidae) are small mammals that can be barely noticed in nature. However, there are many interesting facts that make them noteworthy, including echolocation - the ability to navigate with the help of echoes of the clicks they produce. Apart from the clicks, twitters are also probably used for navigation. The Asian House Shrew (Suncus murinus) moving through an unfamiliar environment produces boom, but it is not yet clear whether this sound is used for navigation. The Piebald Shrew (Diplomesodon pulchellum) produces body vibrations in response to a change in the substrate under their feet. These vibrations may be used for exploration of substrate density to avoid digging in dense sand., and Irena Schneiderová.