1,822 research outputs found
Π₯Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠ° Π±ΠΈΠΎΡ ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ°Π²Π° ΠΈ Π°Π½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ Spinacia oleracea L. ΠΈ Spinacia turkestanica Iljin.: ΡΡΠ°Π²Π½ΠΈΡΠ΅Π»ΡΠ½ΠΎΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅
Spinach is an economically important vegetable crop widely cultivated and consumed worldwide. This early ripening leafy vegetable is rich in bioactive components, fiber, micro and macro elements, vitamins, and has high antioxidant activity. Results of numerous studies on the effects of spinach on human health confirm its beneficial effect. The species S. oleracea L. is cultivated commercially. The ancestor of cultivated spinach is S. turkestanica Iljin, which has a breeding potential for different economically valuable traits. Its biochemical composition has been studied extremely little. The present article offers a comparative evaluation of the biochemical profile and antioxidant activity of cultivated and wild spinach species. The material for the study was a representative sample of 48 collection accessions of spinach from the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). The accessions were grown in 2019 and 2020 in the open ground of the Pushkin and Pavlovsk Laboratories of VIR. The antioxidant activity was studied spectrophotometrically by the DPPH assay of free radical scavenging at a wavelength of 515 nm. A significant similarity of the two species in most biochemical parameters was revealed, which confirms their phylogenetic relationship. Significant differences were found in the content of phenolic elements, which determine the elevated values of antioxidant and antiradical activity of S. turkestanica. The article presents correlation matrices of species biochemical composition, describes general trends, negative relationships and conjugated factors. The identified promising accessions of both cultivated and wild spinach are recommended for breeding for increased content of phenolic compounds, ascorbic acid and antioxidant activity. The result of the study helps to reveal the potential of the crop as a valuable source of bioactive components and high antioxidant activity.Π¨ΠΏΠΈΠ½Π°Ρ - ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈ Π·Π½Π°ΡΠΈΠΌΠ°Ρ ΠΎΠ²ΠΎΡΠ½Π°Ρ ΠΊΡΠ»ΡΡΡΡΠ°, ΡΠΈΡΠΎΠΊΠΎ Π²ΠΎΠ·Π΄Π΅Π»ΡΠ²Π°Π΅ΠΌΠ°Ρ ΠΈ ΠΏΠΎΡΡΠ΅Π±Π»ΡΠ΅ΠΌΠ°Ρ Π²ΠΎ Π²ΡΠ΅ΠΌ ΠΌΠΈΡΠ΅. ΠΡΠΎΡ ΡΠΊΠΎΡΠΎΡΠΏΠ΅Π»ΡΠΉ Π»ΠΈΡΡΠΎΠ²ΠΎΠΉ ΠΎΠ²ΠΎΡ Π±ΠΎΠ³Π°Ρ Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈ Π°ΠΊΡΠΈΠ²Π½ΡΠΌΠΈ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠ°ΠΌΠΈ, ΠΊΠ»Π΅ΡΡΠ°ΡΠΊΠΎΠΉ, ΠΌΠΈΠΊΡΠΎ- ΠΈ ΠΌΠ°ΠΊΡΠΎΡΠ»Π΅ΠΌΠ΅Π½ΡΠ°ΠΌΠΈ, Π²ΠΈΡΠ°ΠΌΠΈΠ½Π°ΠΌΠΈ, ΠΎΠ±Π»Π°Π΄Π°Π΅Ρ Π²ΡΡΠΎΠΊΠΎΠΉ Π°Π½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡΡ. ΠΠ½ΠΎΠ³ΠΎΡΠΈΡΠ»Π΅Π½Π½ΡΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΠ·ΡΡΠ΅Π½ΠΈΡ Π²Π»ΠΈΡΠ½ΠΈΡ ΡΠΏΠΈΠ½Π°ΡΠ° Π½Π° Π·Π΄ΠΎΡΠΎΠ²ΡΠ΅ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°ΡΡ Π΅Π³ΠΎ Π±Π»Π°Π³ΠΎΡΠ²ΠΎΡΠ½ΠΎΠ΅ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅. Π ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π΅ ΠΊΡΠ»ΡΡΠΈΠ²ΠΈΡΡΡΡ Π²ΠΈΠ΄ S. oleracea L. ΠΡΠ°ΡΠΎΠ΄ΠΈΡΠ΅Π»Π΅ΠΌ ΠΊΡΠ»ΡΡΡΡΠ½ΠΎΠ³ΠΎ Π²ΠΈΠ΄Π° ΡΠΏΠΈΠ½Π°ΡΠ° ΡΠ²Π»ΡΠ΅ΡΡΡ Π²ΠΈΠ΄ S. turkestanica Iljin., ΠΎΠ±Π»Π°Π΄Π°ΡΡΠΈΠΉ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΠΎΠΌ Π΄Π»Ρ ΡΠ΅Π»Π΅ΠΊΡΠΈΠΈ ΠΏΠΎ ΡΠ°Π·Π»ΠΈΡΠ½ΡΠΌ Ρ
ΠΎΠ·ΡΠΉΡΡΠ²Π΅Π½Π½ΠΎ-ΡΠ΅Π½Π½ΡΠΌ ΠΏΡΠΈΠ·Π½Π°ΠΊΠ°ΠΌ. ΠΠ³ΠΎ Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡΠ°Π² ΠΈΠ·ΡΡΠ΅Π½ ΠΊΡΠ°ΠΉΠ½Π΅ ΠΌΠ°Π»ΠΎ. Π Π½Π°ΡΡΠΎΡΡΠ΅ΠΉ ΡΠ°Π±ΠΎΡΠ΅ Π΄Π°Π½Π° ΡΡΠ°Π²Π½ΠΈΡΠ΅Π»ΡΠ½Π°Ρ ΠΎΡΠ΅Π½ΠΊΠ° Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΡΠΎΡΠΈΠ»Ρ ΠΈ Π°Π½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΊΡΠ»ΡΡΡΡΠ½ΠΎΠ³ΠΎ ΠΈ Π΄ΠΈΠΊΠΎΠ³ΠΎ Π²ΠΈΠ΄ΠΎΠ² ΡΠΏΠΈΠ½Π°ΡΠ°. ΠΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠΌ Π΄Π»Ρ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΡΠ»ΡΠΆΠΈΠ»Π° ΡΠ΅ΠΏΡΠ΅Π·Π΅Π½ΡΠ°ΡΠΈΠ²Π½Π°Ρ Π²ΡΠ±ΠΎΡΠΊΠ° ΠΈΠ· 48 ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΠΊΠΎΠ»Π»Π΅ΠΊΡΠΈΠΈ ΡΠΏΠΈΠ½Π°ΡΠ° ΠΠΠ . ΠΠ±ΡΠ°Π·ΡΡ Π²ΡΡΠ°ΡΠΈΠ²Π°Π»ΠΈΡΡ Π² 2019 ΠΈ 2020 Π³ΠΎΠ΄Ρ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΠΎΡΠΊΡΡΡΠΎΠ³ΠΎ Π³ΡΡΠ½ΡΠ° ΠΡΡΠΊΠΈΠ½ΡΠΊΠΈΡ
ΠΈ ΠΠ°Π²Π»ΠΎΠ²ΡΠΊΠΈΡ
Π»Π°Π±ΠΎΡΠ°ΡΠΎΡΠΈΠΉ ΠΡΠ΅ΡΠΎΡΡΠΈΠΉΡΠΊΠΎΠ³ΠΎ ΠΈΠ½ΡΡΠΈΡΡΡΠ° Π³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΡΡΡΡΠΎΠ² ΡΠ°ΡΡΠ΅Π½ΠΈΠΉ ΠΈΠΌΠ΅Π½ΠΈ Π.Π. ΠΠ°Π²ΠΈΠ»ΠΎΠ²Π°. ΠΠ½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΈΠ·ΡΡΠ°Π»ΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ DPPH Π½Π° ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΎΡΠΎΠΌΠ΅ΡΡΠ΅ ΠΏΡΡΠ΅ΠΌ ΠΏΠΎΠ³Π»ΠΎΡΠ΅Π½ΠΈΡ ΡΠ²ΠΎΠ±ΠΎΠ΄Π½ΡΡ
ΡΠ°Π΄ΠΈΠΊΠ°Π»ΠΎΠ² ΡΠ°ΡΡΠ²ΠΎΡΠ°, ΠΈΠ·ΠΌΠ΅ΡΡΠ΅ΠΌΠΎΠ΅ ΠΏΡΠΈ Π΄Π»ΠΈΠ½Π΅ Π²ΠΎΠ»Π½Ρ 515 Π½ΠΌ. ΠΡΡΠ²Π»Π΅Π½ΠΎ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠ΅ ΡΡ
ΠΎΠ΄ΡΡΠ²ΠΎ Π΄Π²ΡΡ
Π²ΠΈΠ΄ΠΎΠ² ΠΏΠΎ Π±ΠΎΠ»ΡΡΠΈΠ½ΡΡΠ²Ρ Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»Π΅ΠΉ, ΡΡΠΎ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°Π΅Ρ ΠΈΡ
ΡΠΈΠ»ΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠΎΠ΄ΡΡΠ²ΠΎ. Π‘ΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠ΅ ΡΠ°Π·Π»ΠΈΡΠΈΡ ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½Ρ Π² ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠΈ ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ², ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΡΡΠΈΡ
ΠΏΠΎΠ²ΡΡΠ΅Π½Π½ΡΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΡ Π°Π½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΠΎΠΉ ΠΈ Π°Π½ΡΠΈΡΠ°Π΄ΠΈΠΊΠ°Π»ΡΠ½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ S. turkestanica Iljin. Π ΡΡΠ°ΡΡΠ΅ ΠΏΡΠΈΠ²Π΅Π΄Π΅Π½Ρ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΎΠ½Π½ΡΠ΅ ΠΌΠ°ΡΡΠΈΡΡ Π²ΠΈΠ΄ΠΎΠ²ΠΎΠ³ΠΎ Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠ°Π²Π°, ΠΎΠΏΠΈΡΠ°Π½Ρ ΠΎΠ±ΡΠΈΠ΅ ΡΠ΅Π½Π΄Π΅Π½ΡΠΈΠΈ, ΠΎΡΡΠΈΡΠ°ΡΠ΅Π»ΡΠ½ΡΠ΅ Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·ΠΈ ΠΈ ΡΠΎΠΏΡΡΠΆΠ΅Π½Π½ΡΠ΅ ΡΠ°ΠΊΡΠΎΡΡ. ΠΡΠ΄Π΅Π»ΠΈΠ²ΡΠΈΠ΅ΡΡ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΡΠ΅ ΠΎΠ±ΡΠ°Π·ΡΡ ΠΊΠ°ΠΊ ΠΊΡΠ»ΡΡΡΡΠ½ΠΎΠ³ΠΎ, ΡΠ°ΠΊ ΠΈ Π΄ΠΈΠΊΠΎΠ³ΠΎ Π²ΠΈΠ΄ΠΎΠ² ΡΠΏΠΈΠ½Π°ΡΠ° ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄ΠΎΠ²Π°Π½Ρ Π΄Π»Ρ ΡΠ΅Π»Π΅ΠΊΡΠΈΠΈ Π½Π° ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ, Π°ΡΠΊΠΎΡΠ±ΠΈΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ ΠΈ Π°Π½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ. Π Π΅Π·ΡΠ»ΡΡΠ°Ρ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΠΌΠΎΠ³Π°Π΅Ρ ΡΠ°ΡΠΊΡΡΡΡ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π» ΠΊΡΠ»ΡΡΡΡΡ, ΠΊΠ°ΠΊ ΡΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠ° Π±ΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈ-Π°ΠΊΡΠΈΠ²Π½ΡΡ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² ΠΈ Π²ΡΡΠΎΠΊΠΎΠΉ Π°Π½ΡΠΈΠΎΠΊΡΠΈΠ΄Π°Π½ΡΠ½ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ
Main Directions of Environmental Policy of Greenland at Beginning of XXI Century
The individual directions of Greenlandβs environmental policy, which have the greatest impact on the modern ecological situation in the autonomy, are considered. The authors of the work referred to these areas as energy, water resources, waste disposal and pollution control. A description of the development of the selected ecological directions is given, an analysis of their current state is carried out. Greenlandβs environmental cooperation with Denmark and the European Union is also analyzed. The basis of the source study base of the article is the Greenlandic legislation in the field of ecology. The main documents, programs and cases that influenced the development of the selected environmental directions are considered. The relevance of this article lies in a detailed examination of the environmental policy of Greenland and the construction of general conclusions about the environmental situation of the Danish Autonomous Territory based on the results obtained in the analysis of individual environmental areas. The novelty of the study is seen in an integrated approach to the analysis of the ongoing environmental policy of Greenland. The main positive and negative results in the selected environmental areas are noted. An assumption is made about the ambiguity of the environmental policy of Greenland, and possible outcomes in the implementation of this policy are considered
Efficiency and safety of various dual antiplatelet therapy strategies in patients undergoing percutaneous coronary intervention due to myocardial infarction
Aim. To compare the efficacy and safety of prasugrel, ticagrelor, or clopidogrel as part of dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI) due to myocardial infarction (MI).Material and methods. The observational study included 74 patients who underwent PCI due to MI within the first 24 hours after the onset. The patients were devided into 3 groups: group 1 β patients who received ticagrelor as part of DAPT; group 2 β clopidogrel, group 3 β prasugrel. The follow-up period was 28 days. To assess the efficacy and safety of therapy, a composite endpoint was assessed (death + nonfatal recurrent MI (and/or stent rethrombosis) + nonfatal ischemic stroke (IS). Additional secondary endpoints were any moderate and severe (major) bleeding according to the GUSTO and/or TIMI scales. We assessed the incidence of reperfusion arrhythmias, an opening of an infarct-related coronary artery (IRCA), and non-ST elevation myocardial infarction (non-STEMI).Results. The analysis showed no significant differences in the cumulative incidence of adverse outcomes in the study groups within 28 days. The prevalence of secondary endpoints over a 28-day follow-up period was 3,1% in the ticagrelor group and 5,9% in the clopidogrel group, while no moderate and life-threatening bleeding was recorded in the prasugrel group during. There were no significant differences in the incidence of reperfusion arrhythmias, opening of an IRCA, and non-STEMI between the groups.Conclusion. The obtained results suggest the comparable efficacy and safety profiles of prasugrel, ticagrelor and clopidogrel as a part of DAPT in patients undergoing PCI due to MI. There were no significant differences in endpoint event rates. In particular, prasugrel has been shown to be as effective and safe as ticagrelor
Effectiveness of mindfulness-based therapy, stress reduction in hypertension and prehypertension: a systematic review
Aim. To collect and analyze currently available clinical studies on the effectiveness of mindfulness-based stress reduction (MBSR) for lowering blood pressure in individuals with normal, high normal blood pressure and hypertension.Material and methods. The systematic review was prepared according to the PRISMA algorithm with minor modifications. The search algorithm included articles in Russian and English, indexed in the Pubmed/MEDLINE and Cochrane Library databases. The study included studies on the impact of mindfulness interventions on blood pressure levels in individuals aged β₯18 years with an established diagnosis of hypertension, with normal (120-129/80-84 mm Hg) and high normal office blood pressure (130-139/85-89 mm Hg).Results. A total of 4785 publications were identified and included in the study, of which, after a multistage sampling, including screening of articles, 6 studies were included in a qualitative systematic review.Conclusion. Qualitative synthesis of the results of clinical studies revealed that the evidence currently available indicates a possible positive effect of mindfulness interventions on blood pressure levels in individuals with normal, high normal blood pressure and hypertension. However, further studies with larger samples and measurement of more primary and secondary endpoints are required
Mobile applications for anxiety and stress reduction: potential for preventing noncommunicable diseases
The article discusses using mobile applications for smartphones as tools to reduce anxiety and stress. The modern views on pathogenesis of the relationship between stress, anxiety disorders and cardiovascular disease are considered. Based on a review of some representative studies, a methodology for evaluating the characteristics and functions of mobile applications for managing anxiety and stress symptoms is proposed. The applications selected for analysis were tested according to this methodology. There are following key features of the Russianlanguage field of mobile applications for anxiety and stress reduction: a small number of applications, high prevalence of using breathing exercises, meditations and sound therapy, an extremely low disease specificity and focus mainly on helping with general symptoms of anxiety
The effect of the August 21, 2017 total solar eclipse on the phase of VLF/LF signals
An experimental study of the phase and amplitude observations of subβionospheric very low and low frequency signals is performed to analyse the response of the lower ionosphere during the August 21, 2017 total solar eclipse in the United States of America. Three different subβionospheric wave paths are investigated. The length of the paths varies from 2200 to 6400 km and the signal frequencies are 21.4 kHz, 25.2 kHz and 40.75 kHz. The two paths cross the region of the total eclipse and the third path is in the region of 40β60% of obscuration. None of the signals reveal any noticeable amplitude changes during the eclipse while negative phase anomalies (from β33Β° to β95Β°) are detected for all three paths. It is shown that the effective reflection height of the ionosphere in low and middle latitudes is increased by about 3β5 km during the eclipse. Estimation of the electron density change in the lower ionosphere caused by the eclipse, using linear recombination law, shows that the average decrease is by 2.1 to 4.5 times
Disturbances in a VLF radio signal prior the M =4.7 offshore Anzio (central Italy) earthquake on 22 August 2005
Abstract. On 22 August 2005 an earthquake with magnitude M=4.7 occurred in the Anzio (central Italy) offshore area. From 2002, a VLF-LF radio receiver is into operation in Bari (southern Italy). The intensity and the phase of the signals transmitted by GB (f=16 kHz, United Kingdom), FR (f=20.9 kHz, France), GE (f=23.4 kHz, Germany), IC (f=37.5 kHz, Island) and IT (f=54 kHz, Sicily, Italy) has been monitored with a 5 s sampling rate. The previous epicenter is near enough to some of the radio paths and the data collected were studied in order to reveal possible seismic effects. The raw analysis revealed a clear drop in the intensity of the FR radio signal on 19 August. Then the wavelet analysis was applied to the intensity and the phase data of the different radio signals. In the mentioned day an increase in the band 60β120 min was revealed in the spectra of the FR signal. Then the principal component analysis was applied and again the 19 August stood up as an anomalous day for the FR radio signal. The path of this signal, among the paths of the five radio signals collected by the Bari receiver, is the nearest to the mentioned epicentre and the anomaly revealed on 19 August appears as a precursor of the earthquake. This result confirms the possible precursor revealed by other researchers in the air Rn content in a site located 5 miles far from the epicenter
Near-seismic effects in ULF fields and seismo-acoustic emission: statistics and explanation
International audiencePreseismic intensification of fracturing has been investigated from occurrence analysis of seismo-acoustic pulses (SA foreshocks) and ULF magnetic pulses (ULF foreshocks) observed in Karimshino station in addition to seismic foreshocks. Such analysis is produced for about 40 rather strong and nearby isolated earthquakes during 2 years of recording. It is found that occurrence rate of SA foreshocks increases in the interval (-12, 0 h) before main shock with 3-times exceeding of background level in the interval (-6, -3 h), and occurrence probability of SA foreshocks (pA~75%) is higher than probability of seismic foreshocks (ps~30%) in the same time interval.ULF foreshocks are masked by regular ULF activity at local morning and daytime, nevertheless we have discovered an essential ULF intensity increase in the interval (-3, +1 h) at the frequency range 0.05-0.3 Hz. Estimated occurrence probability of ULF foreshocks is about 40%. After theoretical consideration we conclude: 1) Taking into account the number rate of SA foreshocks, their amplitude and frequency range, they emit due to opening of fractures with size of L=70-200 m (M=1-2); 2) The electro-kinetic effect is the most promising mechanism of ULF foreshocks, but it is efficient only if two special conditions are fulfilled: a) origin of fractures near fluid-saturated places or liquid reservoirs (aquifers); b) appearance of open porosity or initiation of percolation instability; 3) Both SA and ULF magnetic field pulses are related to near-distant fractures (r<20-30 km); 4) Taking into account number rate and activation period of seismic, SA and ULF foreshocks, it is rather probable that opening of fractures and rupture of fluid reservoirs occur in the large preparation area with horizontal size about 100-200km
Holocene climate and environmental change in north-eastern Kamchatka (Russian Far East), inferred from a multi-proxy study of lake sediments
The study was supported by the Swedish Research Council through grants 621-2004-5224 and 621-2005-4444 to K.D. Bennett. A. Self and N. Solovieva acknowledge S. Brooks and V. Jones and were supported by NERC grant NE/H008160/1.A sediment record from a small lake in the north-eastern part of the Kamchatka Peninsula has been investigated in a multi-proxy study to gain knowledge of Holocene climatic and environmental change. Pollen, diatoms, chironomids and selected geochemical parameters were analysed and the sediment record was dated with radiocarbon. The study shows Holocene changes in the terrestrial vegetation as well as responses of the lake ecosystem to catchment maturity and multiple stressors, such as climate change and volcanic eruptions. Climate change is the major driving force resulting in the recorded environmental changes in the lake, although recurrent tephra deposition events also contributed. The sediment record has an age at the base of about 10,000 cal yrs BP, and during the first 400 years the climate was cold and the lake exhibited extensive ice-cover during winter and relatively low primary production. Soils in the catchment were poor with shrub alder and birches dominating the vegetation surrounding the lake. At about 9600β8900 cal yrs BP the climate was cold and moist, and strong seasonal wind stress resulted in reduced ice-cover and increased primary production. After ca. 8900 cal yrs BP the forest density increased around the lake, runoff decreased in a generally drier climate resulting in decreased primary production in the lake until ca. 7000 cal yrs BP. This generally dry climate was interrupted by a brief climatic perturbation, possibly attributed to the 8.2 ka event, indicating increasingly windy conditions with thick snow cover, reduced ice-cover and slightly elevated primary production in the lake. The diatom record shows maximum thermal stratification at ca. 6300β5800 cal yrs BP and indicates together with the geochemical proxies a dry and slightly warmer climate resulting in a high productive lake. The most remarkably change in the catchment vegetation occurred at ca. 4200 cal yrs BP in the form of a conspicuous increase in Siberian dwarf pine (Pinus pumila), indicating a shift to a cooler climate with a thicker and more long-lasting snow cover. This vegetational change was accompanied by marked shifts in the diatom and chironomid stratigraphies, which are also indicative of colder climate and more extensive ice-cover.Publisher PDFPeer reviewe
Thiacalix[4]monocrowns with terpyridine functional groups as new structural units for luminescent polynuclear lanthanide complexes
Β© 2016 Β© 2016 A.E. Arbuzov Institute of Organic and Physical Chemistry.The synthesis and structure of thiacalix[4]monocrowns in 1,3-alternate configuration substituted by terpyridyl fragments on the lower rim are being discussed. It has been shown that the number of oxyethylene units in oligoethylene glycol chain affects the distribution of the yields of the cross-linking products leading to either thiacalix[4]monocrowns or bisthiacalix[4]arenes. Their complexation ability towards alkali metal and lanthanide ions has been studied using liquid extraction and MALDI TOF MS, in addition to luminescent properties of ligands and their lanthanide complexes. The NMR titration data discovered the participation of both crown ether and terpyridyl fragment in the coordination of lanthanide cations. The fluorescent titration showed the nonlinear emission response to the amount of lanthanide ions
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