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| 2. |
- Charity, R. J., et al.
(författare)
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Two-proton decay of the 6Be ground state and the double isobaric analog of 11Li
- 2013
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 420:1
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Konferensbidrag (refereegranskat)abstract
- Two-proton decay is discussed in a number of light isobaric multiplets. For the lightest two-proton emitter, 6Be, the momentum correlations between the three decay products were measured and found to be consistent with quantum-mechanical three-cluster-model calculations. Two-proton decay was also found for two members of the A=8 and A=11 quintets. Finally, a third member of the A=11 sextet, the double isobaric analog of the halo nucleus 11Li in 11B was observed by its two-proton decay.
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| 3. |
- Askinazi, L. G., et al.
(författare)
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Evolution of geodesic acoustic mode in ohmic H-mode in TUMAN-3M tokamak
- 2012
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Ingår i: Technical physics letters. - 1063-7850 .- 1090-6533. ; 38:3, s. 268-271
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Tidskriftsartikel (refereegranskat)abstract
- The behavior of a geodesic acoustic mode (GAM) in the TUMAN-3M tokamak has been experimentally studied using the heavy-ion beam probing technique. Oscillations of the electric potential under the action of a GAM localized at the plasma periphery have been detected. The GAM was observed in the regime of low confinement (L-mode) with low plasma density (similar to 0.8 x 10(19) m(-3)) and disappeared upon the transition to a high confinement regime (H-mode). The possible role of GAM as a precursor of the improved confinement (LH-transition) is discussed.
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| 5. |
- Lappalainen, Hanna K., et al.
(författare)
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Pan-Eurasian Experiment (PEEX) : towards a holistic understanding of the feedbacks and interactions in the land-atmosphere-ocean-society continuum in the northern Eurasian region
- 2016
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:22, s. 14421-14461
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Tidskriftsartikel (refereegranskat)abstract
- The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-atmosphereaquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.
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| 6. |
- Stroganova, T. A., et al.
(författare)
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Effects of the Periodicity and Vowelness of Sounds on Auditory Cortex Responses in Children
- 2022
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Ingår i: Neuroscience and Behavioral Physiology. - : Springer Science and Business Media LLC. - 0097-0549 .- 1573-899X. ; 52:3, s. 395-404
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms of the human brain decoding speech sounds are of fundamental and applied interest in many areas of neuroscience. This study addresses the roles of periodicity and the speech nature (fixed formant structure) of vowel sounds in modulating auditory cortex activity in typically developing children. We proposed that both of these characteristics are typical of the vowel sounds of speech and that they are processed by different neural networks in the auditory cortex. To test this hypothesis, we constructed a set of acoustic stimuli by manipulating their periodicity and vowelness separately and used magnetoencephalography combined with individual models of the cortical surface to evaluate the cortical topography of the sources of auditory cortex responses and their strengths. The cohort consisted of nine typically developing children aged 7–12 years. We found that early auditory cortex responses (50–150 msec after stimulus onset) were highly sensitive to both the periodicity and vowelness of sounds, with independent tuning of neural networks to each of these properties of speech sounds. Differences in the locations, time dynamics, and hemisphere asymmetry of these differential responses indicated that “sound vowelness zones” in the temporal cortex constitute the earliest level in the speech information processing hierarchy at which processing of the acoustic properties of a periodic signal is transformed into decoding of speech sounds. These results allow the specific features and roles of possible impairments to the processing of the low-level properties of speech sounds and difficulties in speech perception in children with pervasive developmental disorders to be evaluated.
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| 7. |
- Stroganova, T. A., et al.
(författare)
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Left hemispheric deficit in the sustained neuromagnetic response to periodic click trains in children with ASD
- 2020
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Ingår i: Molecular Autism. - : Springer Science and Business Media LLC. - 2040-2392. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Deficits in perception and production of vocal pitch are often observed in people with autism spectrum disorder (ASD), but the neural basis of these deficits is unknown. In magnetoencephalogram (MEG), spectrally complex periodic sounds trigger two continuous neural responses-the auditory steady state response (ASSR) and the sustained field (SF). It has been shown that the SF in neurotypical individuals is associated with low-level analysis of pitch in the 'pitch processing center' of the Heschl's gyrus. Therefore, alternations in this auditory response may reflect atypical processing of vocal pitch. The SF, however, has never been studied in people with ASD. Methods We used MEG and individual brain models to investigate the ASSR and SF evoked by monaural 40 Hz click trains in boys with ASD (N = 35) and neurotypical (NT) boys (N = 35) aged 7-12-years. Results In agreement with the previous research in adults, the cortical sources of the SF in children were located in the left and right Heschl's gyri, anterolateral to those of the ASSR. In both groups, the SF and ASSR dominated in the right hemisphere and were higher in the hemisphere contralateral to the stimulated ear. The ASSR increased with age in both NT and ASD children and did not differ between the groups. The SF amplitude did not significantly change between the ages of 7 and 12 years. It was moderately attenuated in both hemispheres and was markedly delayed and displaced in the left hemisphere in boys with ASD. The SF delay in participants with ASD was present irrespective of their intelligence level and severity of autism symptoms. Limitations We did not test the language abilities of our participants. Therefore, the link between SF and processing of vocal pitch in children with ASD remains speculative. Conclusion Children with ASD demonstrate atypical processing of spectrally complex periodic sound at the level of the core auditory cortex of the left-hemisphere. The observed neural deficit may contribute to speech perception difficulties experienced by children with ASD, including their poor perception and production of linguistic prosody.
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| 8. |
- Stroganova, T. A., et al.
(författare)
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THE EFFECT OF PERIODICITY AND "VOWELNESS" OF A SOUND ON CORTICAL AUDITORY RESPONSES IN CHILDREN
- 2021
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Ingår i: Zhurnal Vysshei Nervnoi Deyatelnosti Imeni I.P. Pavlova. - 0044-4677. ; 71:4, s. 563-577
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Tidskriftsartikel (refereegranskat)abstract
- The neural basis of speech decoding is of both fundamental and practical interest for many areas of neuroscience. The discovery of highly specialized areas of the temporal cortex, which perform acoustic analysis of vowels and the pitch of spectrally complex periodic sounds, opens the way for new directions in research on speech signal processing in healthy and diseased brain. Here, we sought to dissect the effects of periodicity and "vowelness" of a sound on the neural response of the auditory cortex in typically developing children aged 7-12 years. We hypothesized that although both of these properties are pertinent to speech vowels, their processing occurs at different levels of cortical ventral auditory stream. To test this hypothesis, we constructed a set of acoustic stimuli, manipulating their periodicity and 'vowelness' separately, and used magnetoencephalography in combination with individual brain models to assess the cortical topography and temporal dynamic of cortical sources, which respond selectively to either sounds' periodicity or to their 'vowelness'. We found that the early auditory responses (50-150 ms) were highly sensitive to both periodicity and 'vowelness' of a sound, although they were separable from each other in terms of response timing, source localization and hemispheric asymmetry. Our findings suggest that the separate neural networks are independently tuned for each of these properties of the speech sound, and that transformation of the respective acoustic properties into a speech feature take place at these earliest stages in the speech processing hierarchy. Our results may help to evaluate the role of specific neural deficits in the processing of low-level properties of speech sounds in language disorders.
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| 9. |
- Budnyak, Tetyana, et al.
(författare)
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Imidazole-2yl-Phosphonic Acid Derivative Grafted onto Mesoporous Silica Surface as a Novel Highly Effective Sorbent for Uranium(VI) Ion Extraction
- 2018
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 10:7, s. 6681-6693
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Tidskriftsartikel (refereegranskat)abstract
- A new imidazol-2yl-phosphonic acid/mesoporous silica sorbent (ImP(O)(OH)(2)/SiO2) was developed and applied for uranium(VI) ion removal from aqueous solutions. The synthesized material was characterized by fast kinetics and an extra-high adsorption capacity with respect to uranium. The highest adsorption efficiency of U(VI) ions was obtained for the reaction system at pH 4 and exceeded 618 mg/g. The uranium(VI) sorption proceeds quickly in the first step within 60 min of the adsorbent sites and ion interactions. Moreover, the equilibrium time was determined to be 120 min. The equilibrium and kinetic characteristics of the uranium(VI) ions uptake by synthesized sorbent was found to follow the Langmuir-Freundlich isotherm model and pseudo-second-order kinetics rather than the Langmuir, Dubinin-Radushkevich, and Temkin models and pseudo-first-order or intraparticle diffusion sorption kinetics. The adsorption mechanism for uranium on the sorbent was clarified basing on the X-ray photoelectron spectroscopy (XPS) analysis. The model of UO22+ binding to surface of the sorbent was proposed according to the results of XPS, i.e., a 1:1 U-to-P ratio in the sorbed complex was established. The regeneration study confirms the ImP(O)(OH)(2)/SiO2 sorbent can be reused. A total of 45% of uranium ions was determined as originating from the sorbent leaching in the acidic solutions, whereas when the basic solutions were used, the removal efficiency was 12%.
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| 10. |
- Cooper, L, et al.
(författare)
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Effect of post-brushing mouthwash solutions on salivary fluoride retention--study 2.
- 2012
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Ingår i: The Journal of clinical dentistry. - 0895-8831. ; 23:3, s. 92-6
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study evaluated the effects of three post-brushing mouthwashes containing 0 ppm F, 225 ppm F, and 500 ppm F, respectively, on salivary fluoride retention after brushing with 1450 ppm fluoride (as NaF) toothpaste and rinsing with water immediately after brushing. METHODS: In this three-phase, randomized, cross-over study, an ion-specific electrode was used to measure salivary F levels in thirty trial participants before brushing (Time 0), and after brushing, rinsing with water, and then rinsing with one of the three mouthwashes. Time points evaluated after brushing were one, three, five, 10, 20, 30, 45, and 60 minutes. For saliva sample collections, subjects were asked to pool saliva in their mouths for 10 seconds before spitting out into a container for each of the time points. RESULTS: The AUC0-60 means for F in saliva were 554, 252, and 20 for the 500, 225, and 0 ppm F mouthwash groups, respectively. The 500 ppm F mouthwash resulted in a 2660% increase in total fluoride salivary retention over 60 minutes when compared with the 0 ppm F group, and a 120% increase when compared with the 225 ppm F group. A significant difference (p < 0.001) in the AUC0-60 means between the three groups was observed using analysis of variance (ANOVA). Paired t-tests also showed significant differences in the mean fluoride retention over 60 minutes for all three pair-wise group comparisons (p < 0.001). CONCLUSION: Use of a fluoride mouthwash containing 225 ppm F or 500 ppm F produced a significant increase in salivary fluoride retention following brushing with a 1450 ppm F toothpaste and rinsing with water compared to rinsing without fluoride. The use of the 500 ppm F mouthwash may be of particular benefit to those at high caries risk.
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