Auditory-Visual Integration of Sine-Wave Speech

It has long been known that observers use visual information from a talker’s face to supplement auditory input to understand speech in situations where the auditory signal is compromised in some way, such as in a noisy environment. However, researchers have demonstrated that even when the auditory signal is perfect, a paired visual stimulus will give rise to a different percept from that without the visual stimulus. This was demonstrated by McGurk and McDonald (1976) when they discovered that when a person is presented with an auditory CV combination (e.g., /ba/), and visual speech stimulus (e.g., /ga/), the resulting perception is often a fusion (e.g., /da/) of the two. This phenomenon can be observed in both degraded and non-degraded speech stimuli, suggesting that the integration is not a function of having a poor auditory stimulus. However, other studies have shown that the normal acoustic speech stimulus is highly redundant in the sense that the signal contains more information than necessary for sound identification. This redundancy may play an important role in auditory-visual integration. Shannon et al. (1995) reduced the spectral information in speech to one, two, three, and four bands of modulated noise using the original speech envelope to modulate the same spectral band. The results showed very high intelligibility even for reductions to three or four bands, suggesting that there are tremendous amounts of redundancy in the normal speech signal. Furthermore, Remez et al. (1981) reduced the speech signal to three time-varying sinusoids that matched the center frequencies and amplitudes at the first three formants of the natural speech signal. Again, the results showed high intelligibility (when the subjects were told that the sounds were, in fact, reduced human speech). A remaining question is whether reducing the redundancy in the auditory signal changes the auditory-visual integration process in either quantitative or qualitative ways. The present study addressed this issue by using, like Remez, sine wave reductions of the auditory stimuli, with the addition of visual stimuli. A total of 10 normal-hearing adult listeners were asked to identify speech syllables produced by five talkers, in which the auditory portions of the signals were degraded using sine wave reduction. Participants were tested with four different sinewave reductions: F0, F1, F2, and F0+F1+F2. Stimuli were presented under auditory only, visual only, and auditory plus visual conditions. Preliminary analysis of the results showed very low levels of performance under auditory only presentation conditions for all of the sinewave reductions, even F0+F1+F2. Visual-only performance was approximately 30%, consistent with previous studies. Little evidence of improvement in the auditory plus visual condition was observed, suggesting that this level of reduction in the auditory stimulus removes so much auditory information that listeners are unable to use the stimulus to achieve any meaningful audiovisual speech integration. These results have implications for the design of processors for assistive devices such as cochlear implants.This thesis was supported by an ASC Undergraduate Scholarship and an SBS Undergraduate Research Scholarshi

Testing Emergent Gravity on Galaxy Cluster Scales

Verlinde's theory of Emergent Gravity (EG) describes gravity as an emergent phenomenon rather than a fundamental force. Applying this reasoning in de Sitter space leads to gravity behaving differently on galaxy and galaxy cluster scales; this excess gravity might offer an alternative to dark matter. Here we test these ideas using the data from the Coma cluster and from 58 stacked galaxy clusters. The X-ray surface brightness measurements of the clusters at $0.1 < z < 1.2$ along with the weak lensing data are used to test the theory. We find that the simultaneous EG fits of the X-ray and weak lensing datasets are significantly worse than those provided by General Relativity (with cold dark matter). For the Coma cluster, the predictions from Emergent Gravity and General Relativity agree in the range of 250 - 700 kpc, while at around 1 Mpc scales, EG total mass predictions are larger by a factor of 2. For the cluster stack the predictions are only in good agreement at around the 1 - 2 Mpc scales, while for $r \gtrsim 10$ Mpc EG is in strong tension with the data. According to the Bayesian information criterion analysis, GR is preferred in all tested datasets; however, we also discuss possible modifications of EG that greatly relax the tension with the data.Comment: 19 pages, 5 figures, 5 tables, accepted for publication on JCA

Pyrrolizidine alkaloids in herbal tea and honey: Report on the 2017 Proficiency testing scheme

Pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) are plant toxins which can enter the food chain through different paths. Two affected foods are herbal infusions and honey. This proficiency testing scheme was executed to assess the capabilities of laboratories to determine PAs. 29 laboratories from nine EU Member States plus Singapore registered. On 04. and 06.09.2017 test items and documentation were dispatched to all of those laboratories. By the dead line of 24.10.2017 26 laboratories had reported back results and filled in a questionnaire. Test item HO (acacia honey) was fortified with six PAs/PANOs (Echimidine, Integerrimine, Intermedine, Senecionine, Seneciphylline-NO, and Senkirkine) and 23 laboratories reported results for this item. The same number of laboratories reported for test item HT (herbal infusion) which was naturally contaminated with four PAs after extraction under reductive conditions (Integerrimine, Retrorsine, Senecionine, and Senecivernine). Laboratories had to report the sums of PA and its respective PANO. Satisfying outcomes could only be registered for Senecionine in test item HT and for Echimidine, Intermedine, and Senkirkine in test item HO with 74 %, 85 %, 85 %, and 91 %, respectively, of reported results having a z'-score smaller or equal to |2|. Only four laboratories reported for Integerrimine in both test items. Contrary to test item HT, Senecionine analysis in test item HO showed very unsatisfactory results. Of the 22 z'-scores calculated for Senecionine nine (41 %) were larger than 3. Senecivernine measurements in test item HT showed a similarly unsatisfying outcome with 47 % of reported results having z'-scores larger than 3. Only three laboratories out of the 26 were able to test for all 10 measurands and only one reported all 10 values with z'-scores smaller or equal to |2|. Overall only five laboratories obtained satisfactory z'-scores (≤ |2|) for all their reported results. There are two groups of three isomeric PAs/PANOs each which apparently caused, for a number of laboratories, problems with quantification. This is an issue which deserves heightened attention. The questionnaire contained queries regarding accreditation and experience, preparation conditions for the two test items, chromatographic separation conditions, detection conditions, calibration approach, and a comments section. The answers were evaluated and for selected questions their correlation to the z'-score of Senecionine in test item HO or Senecivernine in test item HT was analysed. For none of the tested questions a significant influence could be shown.JRC.F.5-Food and Feed Complianc

Modified Boltzmann Transport Equation and Freeze Out

We study Freeze Out process in high energy heavy ion reaction. The description of the process is based on the Boltzmann Transport Equation (BTE). We point out the basic limitations of the BTE approach and introduce Modified BTE. The Freeze Out dynamics is presented in the 4-dimensional space-time in a layer of finite thickness, and we employ Modified BTE for the realistic Freeze Out description.Comment: 9 pages, 2 figure

The 3rd Flow Component as a QGP Signal

Earlier fluid dynamical calculations with QGP show a softening of the directed flow while with hadronic matter this effect is absent. On the other hand, we indicated that a third flow component shows up in the reaction plane as an enhanced emission, which is orthogonal to the directed flow. This is not shadowed by the deflected projectile and target, and shows up at measurable rapidities, $y_cm = 1-2$. To study the formation of this effect initial stages of relativistic heavy ion collisions are studied. An effective string rope model is presented for heavy ion collisions at RHIC energies. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field. The typical field strength (string tension) for RHIC energies is about 5-12 GeV/fm, what allows us to talk about "string ropes". The results show that QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. The produced initial state can be used as an initial condition for further hydrodynamical calculations. Such initial conditions lead to the creation of third flow component. Recent $v_1$ measurements are promising that this effect can be used as a diagnostic tool of the QGP

SCORE performance in Central and Eastern Europe and former Soviet Union: MONICA and HAPIEE results

Aims: The Systematic COronary Risk Evaluation (SCORE) scale assesses 10 year risk of fatal atherosclerotic cardiovascular disease (CVD), based on conventional risk factors. The high-risk SCORE version is recommended for Central and Eastern Europe and former Soviet Union (CEE/FSU), but its performance has never been systematically assessed in the region. We evaluated SCORE performance in two sets of population-based CEE/FSU cohorts. Methods and results: The cohorts based on the World Health Organization MONitoring of trends and determinants in CArdiovascular disease (MONICA) surveys in the Czech Republic, Poland (Warsaw and Tarnobrzeg), Lithuania (Kaunas), and Russia (Novosibirsk) were followed from the mid-1980s. The Health, Alcohol, and Psychosocial factors in Eastern Europe (HAPIEE) study follows Czech, Polish (Krakow), and Russian (Novosibirsk) cohorts from 2002–05. In Cox regression analyses, the high-risk SCORE ≥5% at baseline significantly predicted CVD mortality in both MONICA [n = 15 027; hazard ratios (HR), 1.7–6.3] and HAPIEE (n = 20 517; HR, 2.6–10.5) samples. While SCORE calibration was good in most MONICA samples (predicted and observed mortality were close), the risk was underestimated in Russia. In HAPIEE, the high-risk SCORE overpredicted the estimated 10 year mortality for Czech and Polish samples and adequately predicted it for Russia. SCORE discrimination was satisfactory in both MONICA and HAPIEE. Conclusion: The high-risk SCORE underestimated the fatal CVD risk in Russian MONICA but performed well in most MONICA samples and Russian HAPIEE. This SCORE version might overestimate the risk in contemporary Czech and Polish populations

Anthropometric trends and the risk of cardiovascular disease mortality in a Lithuanian urban population aged 45-64 years

To estimate trends in anthropometric indexes from 1992 to 2008 and to evaluate the risk of cardiovascular disease mortality in relation to anthropometric indexes (body mass index, waist circumference, waist:hip ratio, waist:height ratio)