Climate features that influence life cycles, notably severity, seasonality, unpredictability and variability, are summarized for different polar zones. The zones differ widely in these factors and how they are combined. For example, seasonality is markedly reduced by oceanic influences in the Subantarctic. Information about the life cycles of Arctic and Antarctic arthropods is reviewed to assess the relative contributions of flexibility and programming to life cycles in polar regions. A wide range of life cycles occurs in polar arthropods and, when whole life cycles are considered, fixed or programmed elements are well represented, in contrast to some recent opinions that emphasize the prevalence of flexible or opportunistic responses. Programmed responses ale especially common for controlling the appearance of stages that are sensitive to adverse conditions, such as the reproductive adult. The relative contribution of flexibility and programming to different life cycles is correlated with taxonomic affinity (which establishes the general lifecycle framework for a species), and with climatic zone, the habitats of immature and adult stages, and food., Hugh V. Danks, and Lit
The second half of the 18th century marked an extraordinary flowering of music, especially church music in the Czech lands. Monastic churches, in particular, were characterised by a high level of music production performed by choral scholars whose liturgical music was conducted by chosen monks. Some members of religious orders also composed. These were for example M. J. Haberhauer (1746-1799), a member of the Benedictine order situated in Rajhrad near Brno and P. J. Marek (1748-1806) who belonged to the Augustinian monastery in Brno. Both of them got a musical education as choral scholars and remained musically active also after entering orders. Eventually these two authors both performed as chorregents in the 70’s and early 80’s of the 18th century and they collected sacred and secular pieces of music of their more famous and popular contemporaries (C. Ditters, F. X. Brixi, Haydn, etc.). Apart from a few exceptions they were only composing liturgical works. Haberhauer bequeathed 90 compositions, most of whom composed of Mass for choir and solo accompanied with instrumental ensemble as well as vespers and motets. Marek, however, composed only 21 church compositions and most of them consist of Marian antiphons and litanies of Loreto. These were necessary at the Augustinians, given the honor rendered to the picture of Virgin Mary placed in their church. The two monasteries ran a mutual cooperation which can be proved by Haberhauer music collection preserved at Augustinians in Brno. Haberhauer work can be also found in the collections of other Moravian churches and also at Prague Benedictine order. While Marek’s compositions were exclusively connected to the Augustinian monastery in Brno. Their pieces of music are purely purposeful showing features of a musical classicism. Lives and works of both composers are now the subject of research of the author and of Pavel Žůrek from the Ins, Irena Veselá., and Obsahuje bibliografické odkazy
Stať představuje jednoduchý nástroj měření konceptu tzv. přemosťujícího sociálního kapitálu (PSK) pomocí baterie otázek dotazujících odlišnosti v okruhu přátel adaptovanou pro podmínky dospělé populace v ČR. Tato baterie byla použita ve výzkumu veřejného mínění Naše společnost 2007-04 (CVVM). Nejprve ověřujeme konvergentní a diskriminační validitu nástroje pomocí explorační a konfirmační faktorové analýzy, ve které sledujeme, zda je koncept vícedimenzionální. Výsledky ukazují, že o přemosťujícím sociálním kapitálu je třeba uvažovat ve třech různých dimenzích: odlišný životní způsob, okrajové skupiny a odlišné zájmy. Dále ověřujeme pomocí strukturního modelu konstruktovou validitu. Vycházíme z teoretického modelu pozitivních efektů strukturní dimenze sociálního kapitálu (diverzita v přátelských vazbách) na jeho kulturní dimenzi (tolerance, důvěra). Pozornost věnujeme také položkové reliabilitě škál PSK. Závěrem navrhujeme doporučení pro využití baterie PSK v dalších výzkumech., Jiří Šafr, Julia Häuberer., tabulky, obrázky, and Obsahuje bibliografii
In view of the extremely high metabolic rates involved, insect flight offers a fascinating model system for studying metabolism during exercise, including its regulation by metabolic neurohormones. In our laboratory the African migratory locust, Locusta migratoria, well-known for its long-distance flights, is used as an internationally recognized model insect. The insect is mass-reared under controlled conditions; its size permits convenient handling in vivo and in vitro, while flight activity can be easily evoked. In addition, research on this pest insect may be of economical importance.
A survey of the energy metabolism during locust flight is presented in Fig. 1. Flight activity stimulates the neurosecretory adipokinetic cells in the glandular lobes of the corpus cardiacum, a neuroendocrine gland connected with the insect brain, to release peptide neurohormones, the adipokinetic hormones (AKHs). The target for these hormones is the fat body. Via signal transduction processes, the action of the hormones ultimately results in the mobilization of both carbohydrate and lipid reserves as fuels for flight. Carbohydrate (trehalose) is mobilized from glycogen reserves, implying hormonal activation of the key enzyme, fat body glycogen phosphorylase, by phosphorylation. Similarly, on the lipid side, sn-1,2-diacylglycerol (DAG) is mobilized from stored triacylglycerol (TAG), by hormonal activation of the fat body TAG lipase. The carbohydrate and lipid substrates are transported in the hemolymph to the contracting flight muscles. Carbohydrate provides most of the energy for the initial period of flight, whereas at a later stage, lipid substrate in the blood is increased and gradually takes over. The transport of DAG requires specific lipoprotein carriers (lipophorins) which differ in several respects from the lipoproteins in mammals, and act as a lipid shuttle.
This review is focused on three interrelated topics, covering recent data on the biosynthesis and release of the AKHs, their signal transduction mechanisms in the fat body cells, and the changes in the lipophorin system induced by the AKHs during flight., Dick J. Van Der Horst, Wil J.A. Van Marrewijk, Henk G.B. Vullings, Jacques H.B. Diederen, and Lit
The monophyly of the subgenus Leptempis Collin of the genus Empis L. is established on the basis of a male hypopygial character, and the possibility of a close relationship between the subgenera Leptempis Collin, Planempis Frey and Kritempis Collin is discussed. Seven new species belonging to Empis (Leptempis) rustica-group are described from France, Germany, Greece and Spain: E. (L.) abdominalis sp. n., E. (L.) lamellata sp. n., E. (L.) multispina sp. n., E. (L.) pandellei sp. n., E. (L.) lamellimmanis sp. n., E. (L.) sinuosa sp. n. and E. (L.) trunca sp. n. A key to the E. (L.) rustica-group is presented., Christophe Daugeron, and Lit