The Mean Single Molecule Rate (mSMR) in the Analysis of Fluorescence Fluctuations: Measurements on DNA Mixtures of Defined Composition

We present a method for the evaluation of fluorescence fluctuations on the basis of Mandel’s Q parameter, using sampling time-dependent factorial cumulants. By relating the Q parameter to the sampling time, we obtain the mean single molecule rate (mSMR), an easy to interpret expression that provides both brightness and diffusion information. The model is suitable for the widely used confocal setups with single photon excitation and a single detection channel. We present a way to correct the mSMR for afterpulsing, dead time and background noise. To account for photokinetic effects at short sampling times, we expand the model by a simple on/off isomerization term, which is similar to the well-known triplet model. The functionality of the mSMR is shown using Monte Carlo simulations. The correction mechanisms and the experimental applicability of the model are then demonstrated by DNA measurements of defined composition. By systematically analyzing DNA mixtures, we can show that at large sampling times, the mSMR correctly describes the single molecule brightness rates and the diffusive properties of DNA molecules. At short sampling times, the photokinetic effects of isomerization are accurately described by the mSMR model. Since additionally the mSMR can easily be corrected for measurement artefacts such as detector dead time, afterpulsing and background noise, this is a valuable advantage over the standard method of fluorescence correlation spectroscopy.

Rank-Invariance Conditions for the Comparison of Volatility Forecasts

The paper derives four conditions which guarantee rank–invariance, i.e. that the empirical rankings (based on measurement error–affected variance proxies) of competing volatility forecasts be consistent with the true rankings (based on the unobservable conditional variance). The first three establish bounds beyond which the separation between the forecasts is enough for their rankings not to be affected by the measurement error. The conditions’ ability to establish rank-invariance with respect to forecast characteristics, such as bias, variance and correlation, is studied via Monte Carlo simulations. An additional moment condition identifies the functional forms of the triplet {model, estimation criterion, loss} for which the effects of measurement errors on the rankings cancel altogether. Both theoretical and empirical results show the extension of admissible loss functions achieving ranking consistency in forecast evaluations.

A closer look at CP-violating Higgs portal dark matter as a candidate for the GCE

A statistically significant excess of gamma rays has been reported and robustly confirmed in the Galactic Center over the past decade. Large local dark matter densities suggest that this Galactic Center Excess (GCE) may be attributable to new physics, and indeed it has been shown that this signal is well-modelled by annihilations dominantly into $$ b\overline{b} $$ b b ¯ with a WIMP-scale cross section. In this paper, we consider Majorana dark matter annihilating through a Higgs portal as a candidate source for this signal, where a large CP-violation in the Higgs coupling may serve to severely suppress scattering rates. In particular, we explore the phenomenology of two UV completions, a singlet-doublet model and a doublet-triplet model, and map out the available parameter space which can give a viable signal while respecting current experimental constraints.

Distinguishing inert Higgs doublet and inert triplet scenarios

In this article we consider a comparative study between Type-I 2HDM and $$Y=0$$Y=0, SU(2) triplet extensions having one $$Z_2$$Z2-odd doublet and triplet that render the desired dark matter(DM). For the inert doublet model (IDM) either a neutral scalar or pseudoscalar can be the DM, whereas for inert triplet model (ITM) it is a CP-even scalar. The bounds from perturbativity and vacuum stability are studied for both the scenarios by calculating the two-loop beta functions. While the quartic couplings are restricted to $$0.1-0.2$$0.1-0.2 for a Planck scale perturbativity for IDM, these are much relaxed (0.8 ) for ITM. The RG-improved potentials by Coleman-Weinberg show the regions of stability, meta-stability and instability of the electroweak vacuum. The constraints coming from DM relic, the direct and indirect experiments like XENON1T, LUX and H.E.S.S., Fermi-LAT allow the DM mass $$\gtrsim 700, \,1176$$≳700,1176 GeV for IDM, ITM respectively. Though mass-splitting among $$Z_2$$Z2-odd particles in IDM is a possibility for ITM we have to rely on loop-corrections. The phenomenological signatures at the LHC show that the mono-lepton plus missing energy with prompt and displaced decays in the case of IDM and ITM can distinguish such scenarios at the LHC along with other complementary modes.

The Development of Research in the Field of Chemistry Education at the University of Novi Sad since the Breakup of the Socialist Federal Republic of Yugoslavia

The first PhD thesis in the field of Chemistry Education at the Faculty of Sciences, University of Novi Sad, was defended in 1992. This can be regarded as the symbolic dawn of Chemistry Education as a scientific discipline in this region. After the official breakup of the Socialist Federal Republic of Yugoslavia, research that had started in the 1980s, and which was focused on the development of tools for assessing the quality and flexibility of student knowledge, was continued through the 1990s. This research included the application of computers to chemistry teaching, as well as the development of appropriate chemistry learning programmes. In the following period, research focused on the analysis of chemical teaching programmes in the Republic of Serbia, with a special emphasis on the possibility of including eco-chemical content in curricula. Accordingly, potentially efficient models were suggested. The most recent research has been focused on the investigation of the effectiveness of instructional strategies based on a systemic approach and a triplet model of content representation, using combined measures of students’ performance and mental effort. In this regard, tools for the efficient assessment of knowledge (systemic synthesis questions, context-based questions) have been developed along with tools for the efficient assessment of students’ misconceptions (multi-tier tests). Furthermore, in order to make teaching more effective, procedures for assessing the cognitive complexity of chemical problems have recently been developed and subsequently validated both statistically and by applying Knowledge Space Theory.