Perennial grasses belonging to the genus Molinia are widespread in most of Europe and consist of a polyploid complex of closely related taxa with a confusing taxonomy. Based on extensive sampling at 241 localities in Europe, four cytotypes were identified based on chromosome counts and results of flow cytometry: tetraploids (2n = 36), hexaploids (2n = 54), octoploids (2n = 72) and dodecaploids (2n = 108). While tetra- and dodecaploids were commonly recorded, octoploids were less common and only two hexaploid individuals were identified. Previously reported decaploid counts (2n = 90) from central Europe are probably erroneous and refer to 2n = 108. The tetraploid cytotype is distributed throughout Europe and broadly sympatric with other cytotypes. Octo- and dodecaploids were spatially separated with dodecaploids occurring in the western, central and south-central part of Europe and octoploids in the east-central and southeastern part of Europe. All quantitative characters measured (lengths of lemmas, anthers, caryopses and stomata, lengths of the longest hair on the callus and diameter of the culm below the panicle) showed a linear trend across ploidy levels. Tetra-, octo- and dodecaploid cytotypes formed almost non-overlapping groupings in principal component and discriminant analyses of morphological characters. The following taxonomic concept of this complex is proposed: Molinia caerulea (L.) Moench is a predominantly tetraploid taxon incorporating very rarely reported hexaploid and perhaps also diploid plants; higher cytotypes (2n = 8x, 12x) are considered to be M. arundinacea Schrank, consisting of two subspecies: a dodecaploid subspecies occurring in the southern and western part of central Europe and the octoploid Molinia arundinacea subsp. freyi Dančák in east-central and southeastern Europe.
As a result of inconsistencies in morphological characters, Cerastium pumilum and C. glutinosum have been misunderstood or confused in many European floras since the 1960s. In the second volume of the Flora Nordica, a revised treatment of C. pumilum s.l. is provided and this concept is tested here for eastern Central European populations. The cytometric and morphological part of the study is based on living plants from 85 populations in the Czech Republic, Slovakia, Poland, Austria and Hungary. Flow cytometric analyses of the samples revealed two groups differing in ploidy level and corresponding to two cytotypes (a known octoploid, 2n ≈ 72, for C. glutinosum and yet unknown dodecaploid, 2n ≈ 108, for C. pumilum). Eleven morphological characters were scored or measured in plants of known ploidy level and the data set analysed using multivariate statistics (principal component analysis and canonical discriminant analysis); the two morphologically well-separated groups were identical with the two cytotype groups detected by flow cytometry. Based on these results, we suggest treating the detected cyto-morphotypes as the species C. pumilum and C. glutinosum. Our analysis further revealed that the traditionally used characters (glabrous vs. hairy adaxial surface and presence vs. absence of a scarious margin to the tip of the lowermost bracts) are not taxonomically informative. The characters best differentiating the species include indument on the lowermost vernal internodium, length of mature stylodia, length of glandular hairs on sepals and maximum diameter of mature seed. A key for identification of both species is also provided. A revision of almost 1600 specimens deposited in 16 Central European herbaria revealed that the species show different distribution patterns in Central Europe and partial habitat segregation. Specimens from the Czech Republic previously assigned to C. litigiosum were identified as C. pumilum; consequently, C. litigiosum must be removed from the Czech flora.
The paper deals with the process of optical-fiber drawing and shows research results achieved at the Department of Optical Fibers, Institute of Photonics and Electronics AS CR, v.v.i. (ÚFE). It presents description of basic processes in glass materials during drawing of optical fibers from preforms as well as description of experimental devices used in the ÚFE. It shows examples of results of drawing of optical fibers doped with rare-earth elements both with circular and non-circular cross-sections intended for fiber lasers and amplifiers. It also deals with drawing of special optical fibers for fiber-optic sensors, such as sectorial s-fibers, inverted-graded index fibers, fibers form soft optical glasses, chalkogenide fibers and microstructure fibers. Continuous preparation of optical fibers coated with anatase nanoparticles is also discussed in the paper. and Článek se zabývá procesem tažení optických vláken na základě výsledků výzkumu Oddělení optických vláken Ústavu fotoniky a elektroniky AV ČR, v.v.i. (ÚFE). Je v něm uveden souhrn základních procesů ve skelných materiálech při tažení vláken z preforem i popis unikátních experimentálních zařízení v ÚFE. Dále jsou ukázány příklady výsledků tažení vláken dopovaných prvky vzácných zemin s kruhovým i nekruhovým průřezem pro vláknové lasery a zesilovače. Článek rovněž popisuje tažení speciálních vláken pro optické vláknové senzory jako jsou sektorová vlákna, vlákna s invertovaným gradientním profilem, vlákna z nízkotavitelných optických skel, vlákna chalkogenidová i vlákna mikrostrukturní. V závěru se článek zabývá kontinuálním tažením vláken pokrytých nanočásticemi anatasu pro fotokatalýzu.
The presented data and metadata include answers to questions raised in the questionnaire focused on the experience of teaching practicums and their role in the practical preparation of English language teachers at the Faculty of Arts, Charles University, as well as a basic quantitative analysis of the answers.
The analysis of the questionnaires shows that trainees are, in most cases, prepared for their teaching practicum both professionally and in terms of pedagogy and psychology, and the use of reflective teaching methods seems very useful. The benefits of the teaching practicum include, in particular, getting to know the real situation of teaching in secondary schools and working with a larger group of pupils, getting to know oneself as a teacher, gaining self-confidence, and becoming aware of one's own limits and areas for improvement. The downsides of the current system of teaching practice include mainly the low time allocation, the lack of integration of the practice in the curriculum, and the lack of involvement of the trainee in the daily running of the school (administrative work, supervision, meetings) and the lack of quality feedback from the faculty teacher.
Společnost Škoda Holding, a.s., a Západočeská univerzita v Plzni založily obecně prospěšnou společnost Regionální technické muzeum, o.p.s., se záměrem vybudovat v areálu průmyslového závodu Škoda v Plzni science center. and Monika Kovandová.