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Tytuł:
Progression of clock DBD changes over time
Autorzy:
Maciuk, Kamil
Varna, Inese
Kudrys, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/27311748.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
GPS
satellite
clock
jump
outlier
DBD
reference clock
Opis:
Day-boundary discontinuity (DBD) is an effect present in precise GNSS satellite orbit and clock products originating from the method used for orbit and clock determination. The non-Gaussian measurement noise and data processing in 24 h batches are responsible for DBDs. In the case of the clock product, DBD is a time jump in the boundary epochs of two adjacent batches of processed data and its magnitude might reach a couple of ns. This article presents the four GNSS (Global Navigation Satellite System) systems DBD analysis in terms of change over an 8 year period. For each of 118 satellites available in this period, the yearly value of DBD was subject to analysis including standard deviation and frequency of outliers. Results show that the smallest DBDs appear in the GPS system, the biggest - for the BeiDou space segment. Moreover, the phenomenon of changes in DBDs over time is clearly seen at the beginning of the analysed period when the magnitude and number of the DBDs were larger than for current, newest clock products.
Źródło:
Metrology and Measurement Systems; 2023, 30, 3; 499--505
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical interconnections in future VLSI systems
Autorzy:
Tosik, G.
Lisik, Z.
Gaffiot, F.
Powiązania:
https://bibliotekanauki.pl/articles/308635.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
optical interconnects
clock skew
clock distribution network
OCDN
OVLSI
Opis:
This paper is focused on the latency and power dissipation in clock systems, which should be lower when the optical interconnects are applied. Simulation shows that the power consumed by an optical system is lower than that consumed by an electrical one, however the advantages of optics drastically decrease with the number of output nodes in H-tree. Additionally, simple replacement of an electrical system by an optical clock distribution network (CDN) results in high clock skew, which will be higher than 10% of the clock period for the 32 nm technology node.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 3; 105-108
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aging of ground Global Navigation Satellite System oscillators
Autorzy:
Maciuk, Kamil
Powiązania:
https://bibliotekanauki.pl/articles/2087021.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
clock
GNSS
oscillator
positioning
time
Opis:
Global Navigation Satellite System (GNSS) are widely used in many areas of human life and activity. The proper functioning of GNSS systems depends on several factors, the most important of which is the correct knowledge of time. The position indirectly is based on the knowledge of the distance, which is determined based on time with the knowledge of the speed of the electromagnetic wave. Thus, proper (accurate) knowledge of time (GNSS clock stability) is a key to precise positioning. In this text, the long-term stability of the GNSS station clocks covering the years 1994-2020 was analysed. For this purpose, the corrections of the clocks at selected permanent stations were used, and their stability was determined for all years separately. Then the change of clock stability over time and the search for correlation were analysed. As the results showed, there are clearly differences between four of the type of oscillators analysed. In case of the comparison on an annual basis, no change over time was found.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 2; 371--376
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Precision spectroscopy of cold strontium atoms, towards optical atomic clock
Autorzy:
Bober, M.
Zachorowski, J.
Gawlik, W.
Morzyński, P.
Zawada, M.
Lisak, D.
Cygan, A.
Bielska, K.
Piwiński, M.
Trawiński, R.
Ciuryło, R.
Ozimek, F.
Radzewicz, C.
Powiązania:
https://bibliotekanauki.pl/articles/201653.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser spectroscopy
cold atoms
optical atomic clock
Opis:
This report concerns the experiment of precision spectroscopy of cold strontium atoms in the Polish National Laboratory of Atomic, Molecular and Optical Physics in Toruń. The system is composed of a Zeeman slower and magneto-optical traps (at 461 nm and 689 nm), a frequency comb, and a narrow-band laser locked to an ultra-stable optical cavity. All parts of the experiment are prepared and the first measurements of the absolute frequency of the 1S0-3P1, 689 nm optical transition in 88Sr atoms are performed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 4; 707-710
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanizm zegara biologicznego. Nagroda Nobla 2017 w dziedzinie fizjologii lub medycyny
Mechanism of circadian clock. The 2017 Nobel Prize in physiology or medicine
Autorzy:
Giebultowicz, Jadwiga
Powiązania:
https://bibliotekanauki.pl/articles/1033710.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Przyrodników im. Kopernika
Tematy:
biological clock
circadian rhythms
clock genes
Drosophila melanogaster
Nobel Prize
geny zegarowe
nagroda Nobla
rytmy okołodobowe
zegar biologiczny
Opis:
Since 1901, the Nobel Prize has been awarded to scientists who have made the most important discoveries for the benefit of humanity. The 2017 Nobel Prize in Physiology or Medicine was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young “for their discoveries of molecular mechanisms controlling the circadian rhythm.” It may be surprising to learn that those three scientists dedicated their entire careers to research on the fruit fly, Drosophila melanogaster. However, as their studies progressed, it became increasingly clear that the mechanism of the biological clock that they discovered in Drosophila is very similar to a timekeeping mechanism present in mammals, including humans. Through interdisciplinary work between scientists performing basic research on model organisms and medical doctors, we have learned over time that daily rhythms support human health while disruption of these rhythms is associated with a range of pathological disorders such as cardiovascular problems, metabolic, neurological, and many other diseases. This short review highlights critical milestones on the way to understanding biological clocks, focusing on the roles played by the three Nobel Prize winners.
Od roku 1901 Nagroda Nobla jest przyznawana naukowcom za najważniejsze odkrycia służące dobru ludzkosci. Nagrodę Nobla w dziedzinie fizjologii lub medycyny w 2017 roku otrzymali trzej amerykańscy uczeni Jeffrey C. Hall, Michael Rosbash i Michael W. Young "za odkrycie mechanizmu molekularnego, który kontroluje rytmy okołodobowe". Może się to wydać zaskakujące, ale ci trzej nobliści poświęcili swoje kariery naukowe badaniom nad muszką owocową, Drosophila melanogaster. Jednak w miarę postępu ich badań stawało się coraz bardziej oczywiste, że mechanizm zegara biologicznego, odkryty u muszki Drosophila, jest bardzo podobny do zegara, który posiadają ssaki, łącznie z człowiekiem. Interdyscyplinarna współpraca między naukowcami prowadzącymi badania podstawowe na organizmach modelowych i lekarzami prowadzącymi badania kliniczne ujawniła istotną rolę rytmów dobowych w utrzymaniu zdrowia człowieka. Dlugotrwałe zakłócenie tych rytmów stanowi czynnik ryzyka wielu patologii, takich jak choroby serca, cukrzyca, otyłość czy choroby układu nerwowego. Artykuł krótko podsumowuje odkrycia, stanowiące kamienie milowe na drodze poznania mechanizmu zegara biologicznego, ze szczególnym uwzględnieniem roli trzech noblistów 2017 w tym procesie.
Źródło:
Kosmos; 2018, 67, 2; 245-249
0023-4249
Pojawia się w:
Kosmos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of corrections for the Polish time scale UTC(PL) using artificial neural networks
Autorzy:
Luzar, M.
Sobolewski, Ł.
Miczulski, W.
Korbicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/202125.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
neural network
prediction methods
national timescale
atomic clock
Opis:
In this paper, the effectiveness of using Artificial Neural Networks (ANNs) for predicting the corrections of the Polish time scale UTC(PL) (Universal Coordinated Time) is presented. In particular, prediction results for the different types of neural networks, i.e., the MLP (MultiLayer Perceprton), the RBF (Radial Basis Function) and the GMDH (Group Method of Data Handling) are shown. The main advantages and disadvantages of using such types of neural networks are discussed. The prediction of corrections is performed using two methods: the time series analysis method and the regression method. The input data were prepared suitable for the above mentioned methods, based on two time series, ts1 and ts2. The designation of prediction errors for specified days and the influence of data quantity for the prediction error are considered. The paper consists of five sections. After Introduction, in Sec. 2, the theoretical background for different types of neural networks is presented. Section 3 shows data preparation for the appropriate type of neural network. The experimental results are presented in Sec. 4. Finally, Sec. 5 concludes the paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 3; 589-594
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Enhanced IEEE1588 Clock Synchronization for Link Delays Based on a System-on-Chip Platform
Autorzy:
Wei, Xiaohan
Xiong, Xingzhong
Luo, Zhongqiang
Wang, Jianwu
Cheng, Kaixing
Powiązania:
https://bibliotekanauki.pl/articles/1844640.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
clock synchronization
fronthaul
TSN
system-on-chip
IEEE 1588
Opis:
The clock synchronization is considered as a key technology in the time-sensitive networking (TSN) of 5G fronthaul. This paper proposes a clock synchronization enhancement method to optimize the link delays, in order to improve synchronization accuracy. First, all the synchronization dates are filtered twice to get the good calculation results in the processor, and then FPGA adjust the timer on the slave side to complete clock synchronization. This method is implemented by Xilinx Zynq UltraScale+ MPSoC (multiprocessor system-on-chip), using FPGA+ARM software and hardware co-design platform. The master and slave output Pulse Per-Second signals (PPS). The synchronization accuracy was evaluated by measuring the time offset between PPS signals. Contraposing the TSN, this paper compares the performance of the proposed scheme with some previous methods to show the efficacy of the proposed work. The results show that the slave clock of proposed method is synchronized with the master clock, leading to better robustness and significant improvement in accuracy, with time offset within the range of 40 nanoseconds. This method can be applied to the time synchronization of the 5G open fronthaul network and meets some special service needs in 5G communication.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 2; 289-294
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability of GPS and GLONASS onboard clocks on a monthly basis
Autorzy:
Ziętala, Michał
Powiązania:
https://bibliotekanauki.pl/articles/2173471.pdf
Data publikacji:
2022
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
GPS
GLONASS
clock
stability analysis
MGEX
zegar
analiza stabilności
Opis:
This paper presents the stability of the GPS and GLONASS system clocks’ stability. It describes the construction of these two systems and calculated four different Allan variances (AVAR), based on the MGEX (the Multi-GNSS Experiment) clock products. Four used variances allowed making a better analysis of each GNSS system clock. The results are shown at different averaging times from 5 s as successive multiples to 655,360 s in a monthly period. The stability of GPS and GLONASS clocks is included in the range of 10-12~10-14 s. The results showed that GLONASS clocks are stable (10-12~10-14 s) and are affected with white frequency noise (WFM). The GPS clock stability models have more fluctuations for τ > 40,960 s and the mean stability is concluded between 10-12~10-13 s. Mean frequency accuracy for GPS clocks is related with WFM and Random Walk Frequency (RWF). The differences in clock stability are caused by several factors – block type, type of clock and the time of a satellite in orbit. These factors have an influence on stability results.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2022, 114; 193--209
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Endogenous carbon monoxide (CO) as a modulating factor of molecular biological clock in the hypothalamic structures involved in light transmission in pig and wild boar hybrid during long and short day season
Autorzy:
Gilun, P.
Koziorowska-Gilun, M.
Wąsowska, B.
Sowa-Kućma, M.
Kozioł, K.
Romerowicz-Misielak, M.
Kordan, W.
Koziorowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/16647460.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
carbon monoxide
humoral pathway
light
master biological clock
seasonal
Opis:
Mature males of a wild boar-pig crossbreed, during the long and short day season, were used for the study which demonstrates that the chemical light carrier CO regulates the expression of biological clock genes in the hypothalamus via humoral pathways. Autologous blood with experimentally elevated concentrations of endogenous CO (using lamps with white light-emitting diodes) was infused into the ophthalmic venous sinus via the right dorsal nasal vein. Molecular biology methods: qPCR and Western Blot were used to determine the expression of genes and biological clock proteins. The results showed that elevated endogenous CO levels, through blood irradiation, induces changes in genes expression involved in the functioning of the main biological clock located in suprachiasmatic nuclei. Changes in the expression of the transcription factors Bmal1, Clock and Npas2 have a similar pattern in both structures, where a very large decrease in gene expression was shown after exposure to elevated endogenous CO levels. The changes in the gene expression of PER 1-2, CRY 1-2, and REV-ERB α-β and ROR β are not the same for both POA and DH hypothalamic structures, indicating that both structures respond differently to the humoral signal received. The results indicate that CO is a chemical light molecule whose production in an organism depends on the amount of light. An adequate amount of light is an essential factor for the proper functioning of the main biological clock.
Źródło:
Polish Journal of Veterinary Sciences; 2023, 26, 1; 65-82
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient frequency jumps detection algorithm for atomic clock comparisons
Autorzy:
Marszalec, Michał
Lusawa, Marzenna
Osuch, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/1848989.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
time interval
phasetime
frequency jump
ensemble time scale
atomic clock
Opis:
In this paper a new method of frequency jumps detection in data from atomic clock comparisons is proposed. The presented approach is based on histogram analysis for different time intervals averaging phasetime data recorded over a certain period of time. Our method allows identification of multiple frequency jumps for long data series as well to almost real-time jump detection in combination with advanced filtering. Several methods of preliminary data processing have been tested (simple averaging, moving average and Vondrak filtration), to achieve flexibility in adjusting the algorithm parameters for current needs which is the key to its use in determining ensemble time scale or to control systems of physical time scales, such as UTC(PL). The best results have been achieved with the Vondrak filter.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 107-121
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The relationship between working schedule patterns and the markers of the metabolic syndrome: Comparison of shift workers with day workers
Autorzy:
Mohebbi, Iraj
Shateri, Kamran
Seyedmohammadzad, Mirhosein
Powiązania:
https://bibliotekanauki.pl/articles/2180014.pdf
Data publikacji:
2012-09-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
shift work
insulin resistance
metabolic syndrome
abdominal obesity
circadian clock
Opis:
Objectives: This study examined the effect of shift work on developing the metabolic syndrome by comparing groups of exposed and unexposed Iranian drivers. Methods: We considered as night-shift drivers those drivers whose shifts included at least 15 h per week between 9:00 p.m. and 7:00 a.m. Daytime drivers were defi ned as drivers working regularly without shift work. 3039 shift work drivers were selected. These were matched with non-shift workers. The differences in baseline characteristics and the prevalence of the components of the metabolic syndrome were assessed with Student's t test, and chi-square tests. Results: We found central adiposity in 52.0% of the shift workers versus 42.6% of the day workers (p < 0.0001). The hypertension component was not signifi cantly related to shift work (p > 0.05); but there were signifi cant differences as regards other components of the metabolic syndrome (p < 0.0001). Among the shift workers, the odds ratios of the increased FBS, low HDL-C, higher TG levels, as well as higher waist circumference were 1.992 (95% CI: 1.697-2.337), 1.973 (95% CI: 1.759-2.213), 1.692 (95% CI: 1.527-1.874), and 1.460 (95% CI: 1.320-1.616), respectively. The metabolic syndrome was more common among the shift workers (OR = 1.495; 95% CI: 1.349-1.657). Conclusion: In evaluating such results, further consideration is needed to fi nd pathophysiological clarifi cation; in turn, stress linked to shift work must be considered to likely have had a relevant infl uence on the outcome. In our opinion, shift work acts as an occupational factor for the metabolic syndrome.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2012, 25, 4; 383-391
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the GMDH neural network data preparation method on UTC(PL) correction prediction results
Autorzy:
Miczulski, W.
Sobolewski, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/221698.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
GMDH neural network
national timescale
atomic clock
time series analysis
Opis:
The article presents results of the influence of the GMDH (Group Method of Data Handling) neural network input data preparation method on the results of predicting corrections for the Polish timescale UTC(PL). Prediction of corrections was carried out using two methods, time series analysis and regression. As appropriate to these methods, the input data was prepared based on two time series, ts1 and ts2. The implemented research concerned the designation of the prediction errors on certain days of the forecast and the influence of the quantity of data on the prediction error. The obtained results indicate that in the case of the GMDH neural network the best quality of forecasting for UTC(PL) can be obtained using the time-series analysis method. The prediction errors obtained did not exceed the value of š 8 ns, which confirms the possibility of maintaining the Polish timescale at a high level of compliance with the UTC.
Źródło:
Metrology and Measurement Systems; 2012, 19, 1; 123-132
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced clock gating technique for power optimization in SRAM and sequential circuit
Autorzy:
Ashok Kumar, C.
Madhavi, B.K.
Lal Kishore, K.
Powiązania:
https://bibliotekanauki.pl/articles/2141882.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
enhanced clock gating
D-Latch gating
SRAM
sequential circuit
Area
Delay
Opis:
Low power VLSI designs are having wide variety of application usage in real-time. VLSI circuits are analyzed with various power reduction strategies. Existing approaches are used the clock frequency control, switching activity and scaling factor for power reduction. The glitching problem and clock triggering issues are higher therefore; the proposed work utilized the improved circuit of clock gating technique. In this proposed work, the enhanced clock gating with D-latch model is constructed to obtain the less power consumption. The traditional clock gating technique is improved by adding clock triggering on LATCH circuit and adding buffer circuit between the source and load circuitry to reduce the clock switching issues like gitching and clocking activity. Here the SRAM and sequential counter circuits are designed to utilize the power reduction strategy for improving the performance. This is applicable for various applications in real world and utilizing the FPGA and DSP application specific circuits. Experimental results are analyzed to obtain the power reduction result of SRAM and sequential circuit. Area, power, and delay are obtained the better results as compared with the previous work. Overall, design is performed using Xilinx 14.2 ISE suit.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2021, 15, 2; 32-38
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of long short term memory neural networks for GPS satellite clock bias prediction
Autorzy:
Gnyś, Piotr
Przestrzelski, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/1987078.pdf
Data publikacji:
2021-12-30
Wydawca:
Politechnika Gdańska
Tematy:
neural networks
LSTM
time series prediction
clock bias
GNSS
machine learning
Opis:
Satellite-based localization systems like GPS or Galileo are one of the most commonly used tools in outdoor navigation. While for most applications, like car navigation or hiking, the level of precision provided by commercial solutions is satisfactory it is not always the case for mobile robots. In the case of long-time autonomy and robots that operate in remote areas battery usage and access to synchronization data becomes a problem. In this paper, a solution providing a real-time onboard clock synchronization is presented. Results achieved are better than the current state-of-the-art solution in real-time clock bias prediction for most satellites.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2021, 25, 4; 381-395
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phylogeny of Aconitum subgenus Aconitum in Europe
Autorzy:
Boron, P.
Wroblewska, A.
Binkiewicz, B.
Mitka, J.
Powiązania:
https://bibliotekanauki.pl/articles/2130708.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
Aconitum
Caucasus Mts
Europe
ITS
molecular clock
phylogeny
trnL(UAG)-
ndhF
Opis:
Phylogenetic relations within Aconitum subgen. Aconitum (Ranunculaceae) in Europe are still unclear. To infer the phylogeny of the nuclear (ITS) region and chloroplast intergenic spacer trnL(UAG)-ndhF of the chloroplast DNA (cpDNA), we analyzed 64 accessions within this taxon, 58 from Europe and six from the Caucasus Mts. Nuclear ITS sequences were identical in 51 European and two Caucasian accessions, whereas the remaining sequences were unique. cpDNA sequences could be categorized into five haplotypes, i.e., A–E, including a European-Caucasian Aconitum haplotype B. Ten cpDNA sequences were unique. A 5-bp indel distinguished the diploids from the tetraploids. None of the extant European diploids were basal to the tetraploid local group. A phylogenetic tree based on combined ITS and cpDNA sequences (bayesian inference, maximum likelihood, minimal parsimony) placed Aconitum burnatii (Maritime Alps, Massif Central) and A. nevadense (Sierra Nevada, Pyrenees) in a sister group to all other European species. A Bayesian relaxed clock model estimated the earliest split of the Caucasian species during the Late Miocene [ca. 7 million years ago (Mya)], and the divergence of A. burnatii and A. nevadense from the European genetic stock during the Miocene/Pliocene (ca. 4.4 Mya). Diploids in Europe are likely to be descendants of the Miocene European-Caucasian flora linked with the ancient Asian (arctiotertiary) genetic stock. The origins of the tetraploids remain unclear, and it is possible that some tetraploids originated from local, now extinct diploids. Both the diploids and tetraploids underwent rapid differentiation in the Late Pliocene – Quaternary period.
Źródło:
Acta Societatis Botanicorum Poloniae; 2020, 89, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
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