14 research outputs found
1/f noise in the UV solar spectral irradiance
The investigation of the intrinsic properties of the solar spectral irradiance as a function of the ultraviolet (UV) wavelength is attempted by exploiting rare observations performed at the Villard St. Pancrace station of the Lille University of Sciences and Technology ranging from 278 to 400 nm with a step of 0. 05 nm every half an hour from nearly sunrise to sunset. To achieve this goal, the modern method of the detrended fluctuation analysis was applied on the solar spectral irradiance values versus wavelength. This analysis revealed that the solar incident flux at the top of the atmosphere and the solar spectral irradiance at the ground during two overcast sky days fluctuate with the UV wavelength exhibiting persistent long-range power-law behavior. More interestingly, the exponent of the power-law relationship between the fluctuations of the solar spectral irradiance versus UV wavelength at both the top of the atmosphere and the ground is consistently close to unity (of 1/f-type) throughout the day. This 1/f behavior has been detected in many complex dynamical systems, but despite much effort to derive a theory for its widespread occurrence in nature, it remains unexplained so far. According to the above-mentioned findings we speculate that the 1/f property of the incident solar UV flux at the top of the atmosphere could probably drive both the 1/f behavior depicted in the atmospheric components and the solar UV irradiance at the Earth's surface. The latter could influence the UV-sensitive biological ecosystems, giving rise to a 1/f-type variability in the biosphere, which has already been proven by recent observational data. We finally propose that Wien approximation could be multiplied by a 1/f function of wavelength (e. g., of the type of the fractional Brownian motion) in order to reproduce the aforementioned 1/f feature of the solar UV flux. © 2012 Springer-Verlag
Testing of microsatellite primers with different populations of Eurasian spruces Picea abies (L.) Karst. and Picea obovata Ledeb.
From a clone library containing microsatellite DNA fragments of Norway spruce, seven pairs of primers were selected. These primers were tested as markers in the genetic structure analysis of nine populations of Eurasian spruce species Picea abies (L.) Karst. and Picea obovata Ledeb. Five pairs of these primers identified polymorphic loci with allele numbers ranging from 6 to 15. In the populations examined, the observed and expected heterozygosity values assessed at five loci varied from 0.1778 to 0.6556 and from 0.7800 to 0.900, respectively. In the populations examined, the values of Fst index varied from 0.0691 to 0.2551 with
the mean value of 0.1318. On the dendrogram based on Nei genetic distances, the populations formed three groups: Pskov–Ciscarpathya, Komi–Tatarstan–Arkhangelsk, Kazakhstan–Karelia(natural)–Karelia(plantation)–Krasnoyarsk. Five of the primer pairs tested proved to be useful for analysis of the population genetic structure in Eurasian spruce species
Overview of SND hadronic cross section measurements
At the end of 2016 the SND detector resumed data taking at the upgraded VEPP-2000 e+e− collider. The analysis of data accumulated in 2010-2013 with an integrated lumonosity of 70 pb−1 is continuing. Recent results on measurements of various hadronic cross sections are presented
Study of
We present current status of the SND and CMD-3 experiments at the VEPP-2000 e+e− collider and recent result of data analysis on the processes , etc