1,721,057 research outputs found
Discriminating low frequency components from long range persistent fluctuations in daily atmospheric temperature variability
Full text linkThis study originated from recent results reported in literature, which support the existence of long-range (power-law) persistence in atmospheric temperature fluctuations on monthly and inter-annual scales. We investigated the results of Detrended Fluctuation Analysis (DFA) carried out on twenty-two historical daily time series recorded in Europe in order to evaluate the reliability of such findings in depth. More detailed inspections emphasized systematic deviations from power-law and high statistical confidence for functional form misspecification. Rigorous analyses did not support scale-free correlation as an operative concept for Climate modelling, as instead suggested in literature. In order to understand the physical implications of our results better, we designed a bivariate Markov process, parameterised on the basis of the atmospheric observational data by introducing a slow dummy variable. The time series generated by this model, analysed both in time and frequency domains, tallied with the real ones very well. They accounted for both the deceptive scaling found in literature and the correlation details enhanced by our analysis. Our results seem to evidence the presence of slow fluctuations from another climatic sub-system such as ocean, which inflates temperature variance up to several months. They advise more precise re-analyses of temperature time series before suggesting dynamical paradigms useful for Climate modelling and for the assessment of Climate Change
Cytogenetic characterization of cell lines from three sturgeon species
No full textCell lines were established from three sturgeon species. All were maintained for more than 15 subcultures. The cytogenetic characterizationof the three lines yielded the following results: Acipenser baeri 2n=246+/-10, Huso huso 2n = 120 +/- 8, and Acipenser transmontanus 2n = 246 +/- 10
Localization of the repetitive telomeric sequence (TTAGGG)(n) in four sturgeon species
No full textWe analysed the localization of the telomeric sequence (TTAGGG)n in four species of the genus Acipenser, namely A. naccarii (2n = 246 +/- 6), A. ruthenus (2n = 118 +/- 4), A. gueldenstaedti (2n = 256 +/- 6) and A. baeri (2n = 246 +/- 8). The hybridization signal was localized at the telomeres of all chromosomes in A. naccarii, A. ruthenus and A. baeri. In A. gueldenstaedti, two chromosomes were entirely marked with blocks of telomeric repeating sequences. The results are discussed in the light of their evolutionary inference
Gli indicatori per la stima della vulnerabilità alla land degradation da fattori antropici: strumenti per uan efficace pianificazione territoriale
No full textKaryotypic characterization of Acipenser gueldenstaedti with C-, AgNO3, and fluorescence banding techniques
No full textA karyotypic analysis was carried out on the Russian sturgeon using C- and Ag-NOR banding techniques and base specific DNA-binding fluorochromes. The standard karyotype is 2n = 258+/-4. Nucleolar organizer regions are localized on each of the telomers of four metacentric chromosomes, and on one telomer of four metacentric, four acrocentric, and one large metacentric. C-bands are mainly located at the centromeric regions of the acrocentric chromosomes. The biarmed chromosomes exhibit either weak or absent C-bands, but four metacentrics are completely heterochromatic. By means of double staining with complementary fluorochromes, chromomycin A(3) and DAPI, a pattern of fluorescent regions is recognizable. Interspersion of the opposite DNA base pairs along the chromosomes is discussed
Chromosome banding in sturgeons
No full textThe article reviews the present knowledge of chromosome banding in sturgeons and summarizes recent findings obtained by both classical banding techniques (C-banding, fluorescent and silver staining) and molecular methods, such as fluorescent in situ hybridization (FISH). The results are discussed in relation to karyotype organization and chromosome evolution in sturgeons
Predictors of quality of life in a sample of inpatients with schizophrenia in 23 residential facilities in northern Italy
No full textOne size does not fit all: A tale of polycentric development and land degradation in Italy
No full textPolycentric development is one of the fundamental components of the European Spatial Planning and Development (ESPD) strategy and substantiates the legitimacy of a decentralized governance framework. Spatial planning in polycentric regions has often been found to be ineffective in achieving a truly sustainable development. Relatively few studies have explored the nature of the relationship between polycentric development and the increasing sensitivity of Mediterranean landscapes to desertification. This knowledge gap is somewhat surprising given that economic development has often been considered to be a driver of land degradation. Italian socioeconomic and territorial variables were investigated to determine if levels of land sensitivity to desertification (measured using a composite indicator) had increased more rapidly in mono-centric or polycentric systems. Distinctive settlement models have epitomized the spatio-temporal evolution of the composite indicator for the last 50 years. The first model, from the early 1960s to the early 1990s, reflects a spatially centralized and functionally mono-centric development with density, concentration, and agglomeration acting as key factors of change. Local systems with a purely mono-centric structure exhibited increasing levels of land sensitivity. The increase in land sensitivity from the early 1990s to the early 2010s, was spatially decentralized and mostly dependent on place-specific dynamics. Local systems reorganized themselves on the basis of individualized development models, attempting highly differentiated and poorly coordinated development paths. This study documents how the evolution toward spatially balanced polycentric models can mitigate the growth of land sensitivity in specific contexts. Managing transitions towards polycentric models with positive environmental implications calls for a proactive analysis of the background context, a clarification of socio-economic constraints and spatial limits to centralized and/or decentralized development processes
Genetic relationships among sturgeons revealed by RAPD analysis. Journal of Applied Ichthyology
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