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

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

Immune Responses Induced in Mice after Intragastral Administration with Sendai Virus in Combination with Extract of Uncaria Tomentosa

In the present study, the dried hydroalcoholic extract from the bark of Uncaria tomentosa was evaluated as  a potential immunostimulator. BALP/c mice were seven times immunized intragastrically (i.g.) with a formalin-  inactivated whole Sendai virus (SV) with two doses of the dry extract. The efficacy of the U. tomentosa  was evaluated by examining specific IgA in saliva as well as IgG and haemagglutination inhibition  (HI) in serum antibodies by enzyme-linked immunosorbent assay (ELISA) and HI tests. We found that the  animals inoculated with 5.6 mg of the dry extract of U. tomentosa induced higher saliva IgA antibodies.  Furthermore, the mice immunized e.g. with SV plus 0.56 mg of the extract had significantly higher IgA,  IgG and HI antibody responses to SV than did those administered with the SV alone. These results suggest  that dry extract from bark of U. tomentosa is useful as a mucosal adjuvant for mice.

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

Estimating jobs and wealth in the Bioeconomy

- The bioeconomy generates 4.1% of the EU GDP and employs 8.2% of the EU labour force. - Concomitant growth in value added and reduction in number of persons employed resulted in apparent labour productivity gains over the period 2008 - 2015. - Each bioeconomy sector follows its own dynamics, which can also differ from one EU Member State to another. - Looking at dynamic similarities across Member States can help differentiating bioeconomy strategies according to distinct Member State groups for a finer targeting. - Numbers are partly based on estimates, following nova-Institut's methodologyJRC.D.4-Economics of Agricultur