Seshadri constants on principally polarized abelian surfaces with real multiplication

Seshadri constants on abelian surfaces are fully understood in the case of Picard number one. Little is known so far for simple abelian surfaces of higher Picard number. In this paper we investigate principally polarized abelian surfaces with real multiplication. They are of Picard number two and might be considered the next natural case to be studied. The challenge is to not only determine the Seshadri constants of individual line bundles, but to understand the whole Seshadri function on these surfaces. Our results show on the one hand that this function is surprisingly complex: on surfaces with real multiplication in $$\mathbb {Z}[\sqrt{e}]$$ Z [ e ] it consists of linear segments that are never adjacent to each other—it behaves like the Cantor function. On the other hand, we prove that the Seshadri function is invariant under an infinite group of automorphisms, which shows that it does have interesting regular behavior globally.

The Necessity of Performance Measures for Prosecutors

Local prosecutors are responsible for 95 percent of criminal cases in the United States—their charging decisions holding enormous influence over the number of people incarcerated and the length of sentences served. Performance metrics are a tool that can align the vision of elected prosecutors with the tangible actions of their offices’ line attorneys. The right metrics can provide clarity to individual line attorneys around the mission of the office and the goals of their job. Historically, however, prosecutor offices have relied on evaluation metrics that incentivize individual attorneys to prioritize more punitive responses and volume-driven activity—such as tracking the number of cases processed, indictments, guilty pleas, convictions, and sentence lengths. Under these past approaches, funding, budgeting, and promotional decisions are frequently linked to regressive measures that fail to account for just results. As more Americans have embraced the need to end mass incarceration, a new wave of reform-minded district attorneys have won elections. To ensure they are accountable to the voters who elected them into office and achieve the changes they championed, they must align measures of success with new priorities for their offices. New performance metrics predicated on the goals of reducing incarceration and enhancing fairness can shrink prison and jail populations, while improving public trust and promoting healthier and safer communities. The authors propose a new set of metrics for elected prosecutors to consider in designing performance evaluations, both for their offices and for individual attorneys. The authors also suggest that for these new performance measures to effectively drive decarceration practices, they must be coupled with careful, thoughtful implementation and critical data-management infrastructure.

Estimates of the severity of COVID-19 disease

SummaryBackgroundA range of case fatality ratio (CFR) estimates for COVID-19 have been produced that differ substantially in magnitude.MethodsWe used individual-case data from mainland China and cases detected outside mainland China to estimate the time between onset of symptoms and outcome (death or discharge from hospital). We next obtained age-stratified estimates of the CFR by relating the aggregate distribution of cases by dates of onset to the observed cumulative deaths in China, assuming a constant attack rate by age and adjusting for the demography of the population, and age- and location-based under-ascertainment. We additionally estimated the CFR from individual line-list data on 1,334 cases identified outside mainland China. We used data on the PCR prevalence in international residents repatriated from China at the end of January 2020 to obtain age-stratified estimates of the infection fatality ratio (IFR). Using data on age-stratified severity in a subset of 3,665 cases from China, we estimated the proportion of infections that will likely require hospitalisation.FindingsWe estimate the mean duration from onset-of-symptoms to death to be 17.8 days (95% credible interval, crI 16.9–19.2 days) and from onset-of-symptoms to hospital discharge to be 22.6 days (95% crI 21.1-24.4 days). We estimate a crude CFR of 3.67% (95% crI 3.56%-3.80%) in cases from mainland China. Adjusting for demography and under-ascertainment of milder cases in Wuhan relative to the rest of China, we obtain a best estimate of the CFR in China of 1.38% (95% crI 1.23%-1.53%) with substantially higher values in older ages. Our estimate of the CFR from international cases stratified by age (under 60 / 60 and above) are consistent with these estimates from China. We obtain an overall IFR estimate for China of 0.66% (0.39%-1.33%), again with an increasing profile with age.InterpretationThese early estimates give an indication of the fatality ratio across the spectrum of COVID-19 disease and demonstrate a strong age-gradient in risk.

The Aesthetics of X-Junctions: Cognitive Constraints in the Art of Continuous-Line Caricature

This article exposes cognitive constraints in production and perception of caricatures drawn with one continuous line. Constraints in production enable an artist to overcome the complexity of connecting all individual line segments of a conventional caricature. Constraints in perception enable an audience to overcome the complexity of inferring three-dimensional edges and shapes from two-dimensional line segments. In both production and perception, constraints exploit Xjunctions where the continuous line meets itself in crossing and tangent configurations that contribute to the aesthetics of these artworks.

Genetic Variation in Selected Individuals Based on Number of Capsule in M5 Sesame Mutan Lines Detected by RAPD

Sesame (Sesamum indicum L.) is major oilseed crops with advantages in health and food industry. Due to self pollinated crop, breeding program in sesame utilized gamma rays irradiation to increase genetic variation. The research material consisted of 164 genotypes from 22 selected individual mutant line based on the number of capsules in M5 generation. This study is to detect genetic variation in selected individuals based on number of capsules in M5 generation of sesame mutant line using RAPD markers. The analysis consists of percentage of polymorphic loci, analysis of molecular variance and visualized in cluster and co-ordinate analysis. Fifteen primers RAPD were able to amplified 237 loci. Each genotype in populations had the similarity coefficient of 0.29 – 0.85. Variance within selected individual line (66%) was higher than variance among selected mutant lines (34%). Variance in each selected individual line contributed to its high value. Line 34 showed the lowest polymorphism (23.21%) and line 19 depicted the highest polymorphism (61.60%).

Measuring precise radial velocities on individual spectral lines

Context. Stellar activity is the main limitation to the detection of an Earth-twin using the radial-velocity (RV) technique. Despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are facing an obstacle that will be extremely difficult to overcome using current techniques. Aims. In this paper, we investigate a novel approach to derive precise RVs considering the wealth of information present in high-resolution spectra. Methods. This new method consists of building a master spectrum from all available observations and measure the RVs of each individual spectral line in a spectrum relative to this master. When analysing several spectra, the final product of this approach is the RVs of each individual line as a function of time. Results. We demonstrate on three stars intensively observed with HARPS that our new method gives RVs that are extremely similar to the one derived from the HARPS data reduction software. Our new approach to derive RVs demonstrates that the non-stability of daily HARPS wavelength solution induces night-to-night RV offsets with an standard deviation of 0.4 m s−1, and we propose a solution to correct for this systematic. Finally, and this is probably the most astrophysically relevant result of this paper, we demonstrate that some spectral lines are strongly affected by stellar activity while others are not. By measuring the RVs on two carefully selected subsample of spectral lines, we demonstrate that we can boost by a factor of two or mitigate by a factor of 1.6 the red noise induced by stellar activity in the 2010 RV measurements of α Cen B. Conclusions. By measuring the RVs of each spectral line, we are able to reach the same RV precision as other approved techniques. In addition, this new approach allows us to demonstrate that each spectral line is differently affected by stellar activity. Preliminary results show that studying in details the behaviour of each spectral line is probably the key to overcome the obstacle of stellar activity.

To design and develop a fuzzy based power flow controller for the stability improvement of a power system

With the growth and development of power electronics in the field of power system enumerates the new and efficient forms of controlling the power. This paper deals with a systematic approach to design an Interline Power Flow Controller (IPFC) for multi-machine infinite bus power system is proposed. It is an independent controller system which is suitable for an individual line compensation of a multiline power system. A Simulink model of an IPFC based multi-machine system along with fuzzy is developed. The outcomes obtained were compared with the conventional method of tuning the proposed controller to confirm the effectiveness and robustness of the developed controller. The analysis of an IPFC is assuring the response towards the system’s operation. In this proposed scheme, the controller is designed with the series and shunt configuration of an interline power flow controller using fuzzy technology. The two types of configuration in the designed system are manipulated in which most of the compensation in a multiline system is provided by means of the series controller, the shunt controller which is used for the real power compensation. The simulation of a designed system is done using MATLAB software-Simulink.