E-cigarette Tobacco Retail Licensing Laws: Variance Across US States as of January 1, 2020

Objectives. To describe how US states and the District of Columbia regulate e-cigarette sales by examining e-cigarette–specific tobacco retail licensing (TRL) laws. Methods. We coded 25 state-level e-cigarette TRL laws (effective as of January 1, 2020) for provisions we labeled as either “core” (e.g., presence of license terms, fees, and penalties) or “descriptive” (e.g., license fee amount and term length). Results. Overall, 23 laws clearly defined a license term, 23 laws required a license fee, and 19 laws identified penalties for violations that included both license suspension and revocation. Fees widely ranged ($5–$1000 annually), and 8 laws did not explicitly direct fees toward TRL administration or enforcement. No law required that retailers comply with all local, state, and federal tobacco or e-cigarette laws. Conclusions. Most laws contained core TRL provisions. Several laws, however, had minimal license fees and did not direct fees toward administration or enforcement. As youth e-cigarette use increases, more states should consider establishing e-cigarette TRL laws or incorporating provisions into existing TRL laws.

The Long-Term Effects of Long Terms – Compulsory Schooling Reforms in Sweden

We evaluate the impact on earnings, pensions, and further labor market outcomes of two parallel educational reforms increasing instructional time in Swedish primary school. The reforms extended the annual term length and years of compulsory schooling by comparable amounts. We find striking differences in the effects of the two reforms: at 5% the returns to the term length extension were sizeable and benefited broad ranges of the population. The compulsory schooling extension had small (2%) albeit significant effects, which were possibly driven by an increase in post-compulsory schooling. Both reforms led to increased sorting into occupations with heavy reliance on basic skills and the term extension reduced the gender gap in employment and earnings.

The Effects of Sampling Methods on Machine Learning Models for Predicting Long-term Length of Stay

The ability to predict the patients with long-term length of stay (LOS) can aid a hospital's admission management, maintain effective resource utilization and provide a high quality of inpatient care. Hospital discharge data from the Rhode Island Department of Health from the time period between 2010 to 2013 reveals that inpatients with long-term stays, i.e. two weeks or more, costs about six times more than those with short stays while only accounting for 4.7% of the inpatients. With the imbalance in the distribution of long-stay patients and short-stay patients, predicting long-term LOS patients becomes an imbalanced classification problem. Sampling methods—balancing the data before fitting it to a traditional classification model—offer a simple approach to the problem. In this work, the authors propose a new resampling method called RUBIES which provides superior predictive ability when compared to other commonly used sampling techniques.

Senegal (1970–2016)

In Senegal, the presidential term limit and term length rule was subject to nine reforms and one circumvention from 1970 to 2016. This chapter analyses the context, justifications, and repercussions of these reforms. The recurring tenure rule reforms reflect the Senegalese regime’s oscillating trajectory between authoritarian and democratic proclivities. These reforms were frequently part of larger reform packages in which measures to liberalize political competition coincided with measures to constrain competition. Through such strategic reforms, Senghor and Diouf managed to preserve the PS hegemony, but the first electoral turnover in 2000 could ultimately not be prevented. Over the years, tenure rule reforms gained in symbolic value and served as a reference point for electoral promises as well as for public contestation. The strong societal mobilization did not prevent Wade’s third-term bid in 2012, but it did prevent his electoral victory. The contestation of the tenure rule has continued during Sall’s presidency.

Asymptotic scaling laws and semi-similarity solutions for a finite-source spherical blast wave

A spherical blast wave generated by a sudden release of a sphere of compressed gas is an important model problem to understand blast phenomena such as volcanic eruptions and explosive detonations. The resulting explosion flow physics, such as the instability at the gas contact discontinuity and the interaction between the shock wave and the gas contact, are dictated by the initial pressure and sound-speed ratios between the compressed gas and the ambience. Since the initial pressure and sound-speed ratios vary over a wide range in practical applications, it is of interest to investigate the scaling laws and similarity solutions for the spherical symmetric explosion flow. In the present study, numerical simulation of a spherical blast wave is performed. A long-term length scale that incorporates the initial charge radius and the initial pressure ratio is introduced. The trajectories of the main shock normalized by the long-term length scale for a wide range of parameters collapse after a short transition time, indicating an asymptotic similarity solution exists for the far field in the long term. With the assistance of this similarity solution, the full evolution of the main shock can be obtained semi-analytically. For near-field features, i.e. the gas contact and the secondary shock wave, only semi-similarity solutions are observed, which depend on the initial sound-speed ratio but not the initial pressure ratio. The gas contact and the secondary shock share the same scaling relations. Asymptotic analysis is performed to obtain the short-term dynamics of the gas contact, including the gas contact acceleration and the Atwood number, which are the key parameters determining the Rayleigh–Taylor instability development at the gas contact. The asymptotic contact radius as $t\rightarrow \infty$ is also obtained, which is found to be well represented by the long-term length scale and thus only depends on the initial pressure ratio. A simple model of an oscillating bubble is employed to explain the scaling relation of the asymptotic gas contact radius.