Thue-Morse at Multiples of an Integer

Let (t_n) be the classical Thue-Morse sequence defined by t_n = s_2(n) (mod 2), where s_2 is the sum of the bits in the binary representation of n. It is well known that for any integer k>=1 the frequency of the letter "1" in the subsequence t_0, t_k, t_{2k}, ... is asymptotically 1/2. Here we prove that for any k there is a n<=k+4 such that t_{kn}=1. Moreover, we show that n can be chosen to have Hamming weight <=3. This is best in a twofold sense. First, there are infinitely many k such that t_{kn}=1 implies that n has Hamming weight >=3. Second, we characterize all k where the minimal n equals k, k+1, k+2, k+3, or k+4. Finally, we present some results and conjectures for the generalized problem, where s_2 is replaced by s_b for an arbitrary base b>=2.Comment: 14 page

A global climatology of polar lows investigated for local differences and wind-shear environments

Polar lows are intense mesoscale cyclones developing in marine polar air masses. This study presents a new global climatology of polar lows based on the ERA5 reanalysis for the years 1979–2020. Criteria for the detection of polar lows are derived based on a comparison of five polarlow archives with cyclones derived by a mesoscale tracking algorithm. The characteristics associated with polar lows are considered by the following criteria: (i) intense cyclone (large relative vorticity), (ii) mesoscale (small vortex diameter), and (iii) development in the marine polar air masses (a combination of low potential static stability and low potential temperature at the tropopause). Polar lows develop in all marine areas adjacent to sea ice or cold landmasses, mainly in the winter half year. The length and intensity of the season are regionally dependent. The highest density appears in the Nordic Seas. For all ocean sub-basins, forward-shear polar lows are the most common, whereas weak-shear polar lows and those propagating towards warmer environments are second and third most frequent, depending on the area. Reverse-shear polar lows and those propagating towards colder environments are rather seldom, especially in the Southern Ocean. Generally, polar lows share many characteristics across ocean basins and wind-shear categories. The most remarkable difference is that forward-shear polar lows often occur in a stronger vertical wind shear, whereas reverse-shear polar lows feature lower static stability. Hence, the contribution to a fast baroclinic growth rate is slightly different for the shear categories

Economic and legal aspects of international environmental agreements: The case of enforcing and stabilising an international CO 2 agreement

The protection of the global environment is impeded by multilateral externalities which the international community attempts to bring under control by entering into international agreements. International agreements, however, can suffer from non-compliance and free-riding behaviour by sovereign states and must therefore be enforced and stabilised internationally. This paper describes instruments for the enforcement and stabilisation of an international CO2 agreement and evaluates them in the light of economic and legal theory. Economic instruments build on repetition and use utility transfers, economic sanctions and flexible treaty adjustments. Important legal instruments are reciprocal obligations and cooperation duties, international funding and transfer rules, treaty suspension, retorsions and reprisals, treaty revision, and monitoring. The paper shows that economic and legal instruments are compatible to a considerable extent. It develops proposals for the enforcement and stabilisation of a global CO2 agreement and other multilateral treaties.International environmental agreements,international cooperation,non-compliance,enforcement,global warming,international law

Doping high Tc superconductors with oxygen and metallic atoms: A molecular dynamics study

Using classical molecular dynamics based on Lennard-Jones-like potentials, a mechanically stable YBa2Cu3O7 high Tc superconductor structure is generated. This process is controlled via interactive computer graphics. After doping atoms into or removing atoms from the sample using a recently implemented picking mechanism, the lattice oscillation energy is annihilated with a simulated annealing procedure. The remaining minimum ground state energy allows marking of the preferred doping location. Information on the doping mechanism is important because the magnetic and superconducting properties of these compounds depend very strongly on their oxygen conten

The global atmospheric energy transport analysed by a wavelength-based scale separation

Source at https://www.weather-climate-dynamics.net/.The global atmospheric circulation is fundamental for the local weather and climate by redistributing energy and moisture. To the present day, there is a knowledge gap at which spatial scales the energy and its components are transported. Therefore, we separate the meridional atmospheric energy transport in the ERA5 reanalysis by the spatial scales, the quasi-stationary and transient flow patterns, and the latent and dry-static component. We focus on the annual and seasonal mean in the transport components as well as their inter-annual variability. Motivated by similarities across latitudes in the atmospheric transport spectra when displayed as function of wavelength, we refine the existing scale separation method to be based on wavelength instead of wavenumber. This reveals advantageous, as the following conclusions can be drawn, which are fairly similar in the two hemispheres. Transport by synoptic waves, defined at wavelengths between 2,000 and 8,000 km, is the largest contributor to extra-tropical energy and moisture transport, is mainly of transient character, and is little influenced by seasonality. In contrast, the transport by planetary waves, larger than 8,000 km, highly depends on the season and has two distinct characteristics. (1) In the extra-tropical winter, planetary waves are of major importance due to transport of dry-static energy. This planetary transport feature the largest inter-annual variability, and is mainly quasi-stationary in the Northern Hemisphere, but transient in its southern counterpart. (2) In the subtropical summer, quasi-stationary planetary waves are the most important transport component mainly due to advection of moisture, which is associated with monsoons. In contrast to transport by planetary and synoptic waves, only a negligible amount of energy is transported by mesoscale eddies (< 2,000 km)

Simmen, R., Buss, G., Hassler, A. und Immoos, S. (2003). Systemorientierte Sozialpädagogik.

Rezensio

Treatment strategies for treatment naive HIV patients in Germany: evidence from claims data

A recent observational study of HIV patients in Germany suggests that treatment naive patients that are in a more advanced stage of their disease are more likely to receive a treatment regimen based on a boosted protease inhibitor (PI/r) compared with a non-nucleoside reverse-transcriptase-inhibitor (NNRTI) base regimen. To validate those results we analysed claims data of seven German sickness funds from 2009 to 2012 with approximately 4 million beneficiaries. Patients in a more advanced disease state (CDC class C) had a higher likelihood to receive a PI/r based regime rather than a NNRTI based regimen as their initial treatment. There was also a significant correlation between PI/r based regimen and number of comorbidities but not with age. Our results confirm a highly significant relationship between being in a more severe stage of HIV disease and a PI/r based treatment regimen

Treatment strategies for treatment naive HIV patients in Germany: evidence from claims data

A recent observational study of HIV patients in Germany suggests that treatment naive patients that are in a more advanced stage of their disease are more likely to receive a treatment regimen based on a boosted protease inhibitor (PI/r) compared with a non-nucleoside reverse-transcriptase-inhibitor (NNRTI) base regimen. To validate those results we analysed claims data of seven German sickness funds from 2009 to 2012 with approximately 4 million beneficiaries. Patients in a more advanced disease state (CDC class C) had a higher likelihood to receive a PI/r based regime rather than a NNRTI based regimen as their initial treatment. There was also a significant correlation between PI/r based regimen and number of comorbidities but not with age. Our results confirm a highly significant relationship between being in a more severe stage of HIV disease and a PI/r based treatment regimen

The choice between a ritonavir-boosted protease inhibitor- and a non-nucleoside reverse transcriptase inhibitor-based regimen for initiation of antiretroviral treatment - results from an observational study in Germany

Background: This study aims at identifying predictors of the treatment decision of German physicians with regard to a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a ritonavir-boosted protease inhibitor (PI/r) -based initial treatment regimen. Methods: The study is based on a sub analysis of a nation-wide multi-centre, non-interventional, prospective cohort study. 133 patients were identified, who received antiretroviral first-line therapy. By means of a logistic regression, factors that determine the treatment strategy for treatment-naïve patients were analysed. Results: Compared to patients receiving a NNRTI-based initial regimen, patients treated with PI/r are slightly younger, less educated, in a later stage of HIV and have more concomitant diseases. Regression analysis revealed that being in a later stage of HIV (CDC-C) is significantly associated with a PI/r-based treatment decision. Conclusions: Our analysis is the first study in Germany investigating sociodemographic and disease-specific parameters associated with a NNRTI- or a PI/r-based initial treatment decision. The results confirm that the treatment decision for a PI/r strategy is associated with disease severity