Optická vlákna nemusejí sloužit jen pro přenos informace. Pokud do tenkého jádra ve středu vlákna umístíme chemické prvky schopné laserové akce (stimulované emise záření), můžeme generovat velmi intenzivní a přitom kvalitní svazek záření. Vláknové lasery začínají nahrazovat starší typy laserů a otevírají zcela nové obzory v řadě oborů: od lékařství, řezání a sváření v průmyslu až po obranné systémy., Optical fibres also have applications outside the optical telecommunications sphere. If the thin core inside the optical fibre is doped with chemical elements capable of laser action (stimulated emision of radiation), one can generate a very intense and high quality beam of radiation. Fibre lasers have begun to replace older types of lasers and therefore, opens up new horizons in many fields ranging from medicine, industrial cutting and welding to defence., Pavel Peterka, Pavel Honzátko, Ivan Kašík., and Obsahuje seznam literatury
The purpose of this work was to detect groundwater pollution and to identify the conditions of soil and groundwater near the coal waste disposal "Panewniki" Halemba-Wirek Coal Mine using geoelectrical measurements. The firs t applied method was the VLF (Very Low Frequency) technique. This method, using military signals, allowed to perform the in-phase and the quadrature maps. Data were collected from four study areas located near the coal waste dump. Observed anomalies on both maps for each area showed places with different conductivity al lowed to detect the contaminated and uncontaminated zones. The VLF survey indicated that the contamination occurs in the eastern part of study area and is characterized by positive values of both measured electrical fields (the in-phase and the quadrature components). After preliminary contaminated zones were recognized using VLF met hod, an electrical imaging meth od was applied. Two electrical imaging profiles were carried out near the waste dump. The measurements a llowed to create the geoele ctrical model of surrounding area and to investigate the leachate plume. The electrical imaging showed that the greatest pollution occur in the area immediately adjacent to the coal waste what is confirmed by VL F survey. Based on the geological and ge ophysical knowledge from archives and on present researches, the contaminated aquifer with electrical resistivity of 5 to 15 Ω m deposited at depths of 3 to 7 m was found., Arlena Kowalska, Marta Kondracka and Maciej Jan Mendecki., and Obsahuje bibliografické odkazy
We tested whether the known cytochrome c oxidase (COX) inhibition by nitric oxide (NO) could be quantified by VO 2 kinetics during constant load supra-Anaero bic Threshold (AT) exercises in healthy trained or untrained subjects following aerobic training or nitrate administration. In cycle er gometer constant load exercises supra-AT, identified in previous incremental tests, VO 2 kinetics describe a double exponential curve, one rapid and one appreciably slower, allowing the area between them to be calculate in O 2 l. After training, with increased NO availability, this area decreases in inverse ratio to treatment efficacy. In fact, in 11 healthy subjects after aerobic tr aining for 6-7 weeks, area was decreased on average by 51 %. In 11 untrained subjects, following the assumption of an NO donor, 20 mg isosorbide 5 mononitrate, area was decrea sed on average by 53 %. In conclusion, supra-AT VO 2 kinetics in constant load exercises permit the quantification of the inhibitory effect NO-dependent on COX after either physical training or nitrate assumption., D. Maione ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
We recorded and analysed the songs of ten male icterine warblers (Hippolais icterina) in České Budějovice (Czech Republic) to identify mimicry. Imitations represented 76.2 % of the total time of all songs and we detected 42 mimicked species. Barn swallow (Hirundo rustica), blackbird (Turdus merula), common kestrel (Falco tinnunculus) and fieldfare (Turdus pilaris) were the most common species imitated. Principal components analysis (PCA) detected individual variability in the species mimicked. The length of recording needed to detect 95 % of species mimicked was assessed to be 8.2 minutes.
From June to August in 2004 and 2005, we conducted the studies on spontaneous vocalization development of greater horseshoe bat, Rhinolophus ferrumequinum, in Zhi’an Village (Jilin province, Northeast China). In contrast to adult bats, infant bats of the greater horseshoe bat emitted calls characterized by multiharmonics and variable harmonic patterns. With the physical growth of infants, the dominant frequency, pulse duration and frequency of each harmonic of spontaneous calls increased, the number of harmonics decreased from 5–8 to 1–2 and dominant harmonic switched from first to the second with peak frequency increasing. Vocalizations of infant bats of the greater horseshoe bat could be categorized to those serving as precursors of echolocation sounds and those serving as isolation calls used to attract their mothers. According to observation on mother-infant reunion, the female adult bats only suckled their own babies, but not other pups in the same colony. And the mother recognized their own infants through both odor and vocal cues indicating that the isolation calls emitted by infant bats played an important role in mother-infant communication.
Vocalizations of the plaintive cuckoo (Cacomantis merulinus) and brush cuckoo (C. variolosus) were compared. Six major sound types were identified in the plaintive cuckoo, and four in the brush cuckoo. On the basis of song similarity as assessed by sonogram qualitatively and quantitatively, the grey-bellied cuckoo (C. passerinus) was considered conspecific with C. merulinus and the rusty-breasted cuckoo C. sepulcralis was considered conspecific with C. variolosus. The song similarities between C. merulinus and C. variolosus were considered homologous and derived from common ancestry.
The paper reported vocalizations of endemic Tibetan Plateau steppe sparrow, red- necked snow finch (Pyrgilauda ruficollis) by using SAS-Lab Pro. The subject similarity contrast and multivariate contrast were used to study the complexity and stability of sounds. The results indicated that songs of P. ruficollis were highly complicated with varied song types, song phrases, song syllable and combination of them. One song syllable shared by snow finches (Montifringilla nivalis henrici, M. adamsi, P. ruficollis and P. blanfordi) was selected as indicator to compare the taxonomic relationship among them. The similarity contrast and cluster analysis through SPSS were conducted to construct the similarity tree based on this shared syllable’s acoustic parameters including the highest frequency (HF), the lowest frequency (LF), the main frequency (MPF) and duration (DUR). The results revealed that the syllable similarities are accordant with taxonomic status suggested in previous studies based on morphologic, ecological and molecular analysis methods. The syllable shared by these snow finches were presumed to be homologous and derived from a common ancestry. Further studies on songs encoding phylogenetic signal of snow finches are needed.