25 research outputs found

    Longer wings for faster springs – wing length relates tospring phenology in a long-distanc e migrant across its range

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    In migratory birds, morphological adaptations for efficient migratory flight often oppose morphological adaptations for efficient behavior during resident periods. This includes adaptations in wing shape for either flying long distances or foraging in the vegetation and in climate-driven variation of body size. In addition, the timing of migratory flights and particularly the timely arrival at local breeding sites is crucial because fitness prospects depend on site-specific phenology. Thus, adaptations for efficient long-distance flights might be also related to conditions at destination areas. For an obligatory long-distance migrant, the common nightingale, we verified that wing length as the aerodynamically important trait, but not structural body size increased from the western to the eastern parts of the species range. In contrast with expectation from aerodynamic theory, however, wing length did not increase with increasing migration distances. Instead, wing length was associated with the phenology at breeding destinations, namely the speed of local spring green-up. We argue that longer wings are beneficial for adjusting migration speed to local conditions for birds breeding in habitats with fast spring green-up and thus short optimal arrival periods. We suggest that the speed of spring green-up at breeding sites is a fundamental variable determining the timing of migration that fine tune phenotypes in migrants across their range

    Long-term drivers of broadband traffic in next-generation networks

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    This paper is concerned with long-term (20+ years) forecasting of broadband traffic in next-generation networks. Such long-term approach requires going beyond extrapolations of past traffic data while facing high uncertainty in predicting the future developments and facing the fact that, in 20 years, the current network technologies and architectures will be obsolete. Thus, "order of magnitude" upper bounds of upstream and downstream traffic are deemed to be good enough to facilitate such long-term forecasting. These bounds can be obtained by evaluating the limits of human sighting and assuming that these limits will be achieved by future services or, alternatively, by considering the contents transferred by bandwidth-demanding applications such as those using embedded interactive 3D video streaming. The traffic upper bounds are a good indication of the peak values and, subsequently, also of the future network capacity demands. Furthermore, the main drivers of traffic growth including multimedia as well as non-multimedia applications are identified. New disruptive applications and services are explored that can make good use of the large bandwidth provided by next-generation networks. The results can be used to identify monetization opportunities of future services and to map potential revenues for network operators

    Stable isotopes and mtDNA reveal niche segregation but no evidence of intergradation along a habitat gradient in the Lesser Whitethroat complex (Sylvia curruca; Passeriformes; Aves)

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    Niche segregation plays a critical role in the speciation process, but determining the extent to which taxa are geographically or ecologically isolated is challenging. In this study, we use stable isotopes of carbon (δ13C), nitrogen (δ15N), hydrogen (δ2H) and oxygen (δ18O) to test for ecological differences among taxa in the Lesser Whitethroat Sylvia curruca complex. Analysis of mitochondrial DNA (mtDNA) revealed 6 distinct haplotype groups, which conform to at least 5 distinct taxa. Stable isotopes provided insight into geographical and broad-scale ecological differences among haplotypes. The most striking isotope differences were between the populations inhabiting Siberian boreal forest (S. c. blythi) from the one inhabiting semi-desert in Kazakhstan (S. c. halimodendri). It is generally assumed that these two populations form a morphological cline along a gradient from mesic to xeric habitat. Our sample includes a large proportion of morphologically intermediate individuals that appear to represent a hybrid population. However, in all of these, there is strict correspondence between haplotype and isotope signature, suggesting an ecological division on the breeding grounds between all our samples of these two taxa. The lack of ecologically intermediate individuals among our sample of morphologically intermediate ones thus speaks against the existence of a cline. The two taxa blythi and halimodendri emerge as potential models for the study of the early stages of the speciation process. While differences in stable isotopes may be largely influenced by geography, we also demonstrate how, in specific instances (such as the alleged cline reported here), they may be used to evaluate niche segregation between taxa, providing information of importance for determination of species limits

    Measurement of the mass difference m(D-s(+))-m(D+) at CDF II

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    We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)

    A Miniaturized branc-line directional coupler on low temperature cofired ceramic board

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    This paper outlines the capability to develop a 3D compact-size branch-line directional coupler within the LTCC process. The substrate of Dupont Green Tape TM ceramic has been successfully utilized to manufacture 3-dB 9

    Innowacyjny program edukacyjny dotyczący wytwarzania biogazu realizowany na uniwersytetach w Hradec Králové (CZ) i Opolu (PL)

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    Recently, there is a growing pressure on a rapid construction of agricultural biogas plants, particularly in the Czech-Polish border region. It is an area with large expanses of agricultural land which can serve to supply biogas plants with biomass. This strategy should contribute to harmonize the common agricultural policy of the European Union. A need for qualified operators of these stations on this territory is also increasing. Therefore we first include a demonstration of an education program for students in the field of agricultural waste anaerobic fermentation and biogas production. We present here the first part of an innovative approach which we use in the teaching program “Physico-technical Measurements and Computer Technology” at the Faculty of Science at the University of Hradec Kralove and also in the education of internshipers from the Faculty of Natural Sciences and Technology at the University of Opole. There are requirements to fulfil labour market expectations and to make this subject more attractive for the students. Students’ theoretical and practical preparation constitutes a comprehensive source of knowledge and skills required in a real life job. Joined theoretical and practical knowledge gained by students, reinforced by the skills developed during task analysis followed by their solution, provides the future graduate higher quality abilities and better position in the labour market.W ostatnim czasie rośnie nacisk na budowę biogazowni rolniczych, szczególnie w czesko-polskim regionie przygranicznym. Jest to region, gdzie występują duże obszary gruntów rolnych mogących służyć do zasilania biogazowni. Strategia ta powinna przyczynić się do harmonizacji wspólnej polityki rolnej Unii Europejskiej. W związku z powyższym wzrasta również potrzeba wykształcenia wykwalifikowanych operatorów tych stacji. Pierwsza część pracy obejmuje prezentację akademickiego programu edukacyjnego w dziedzinie fermentacji beztlenowej odpadów i wytwarzania biogazu pochodzącego z produkcji rolnej. Zaprezentowano część innowacyjnego podejścia, które wykorzystywane jest w programie nauczania „Pomiary fizyko-techniczne oraz technologie komputerowe” na Wydziale Nauk Przyrodniczych Uniwersytetu Hradec Kralove, a także w edukacji studentów Wydziału Przyrodniczo-Technicznego Uniwersytetu Opolskiego. Wymagania te mają sprostać oczekiwaniom rynku pracy i uczynić kierunek studiów bardziej atrakcyjnym. Powiązanie przygotowania teoretycznego i praktycznego studentów tworzy kompleksowe źródło wiedzy i kształtuje umiejętności niezbędnych do pracy w biogazowniach. Zarówno wiedza teoretyczna, jak i umiejętności praktyczne zdobyte przez studentów, wzbogacone o umiejętności analizy zadań, a następnie ich rozwiązania, zapewnią przyszłym absolwentom większe możliwości i lepszą pozycję na rynku pracy
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