Senior Programmers: Characteristics of Elderly Users from Stack Overflow

In this paper we presents results of research about elderly users of Stack Overflow (Question and Answer portal for programmers). They have different roles, different main activities and different habits. They are an important part of the community, as they tend to have higher reputation and they like to share their knowledge. This is a great example of possible way of keeping elderly people active and helpful for society

Breakdown of adiabatic transfer of light in waveguides in the presence of absorption

In atomic physics, adiabatic evolution is often used to achieve a robust and efficient population transfer. Many adiabatic schemes have also been implemented in optical waveguide structures. Recently there has been increasing interests in the influence of decay and absorption, and their engineering applications. Here it is shown that even a small decay can significantly influence the dynamical behaviour of a system, above and beyond a mere change of the overall norm. In particular, a small decay can lead to a breakdown of adiabatic transfer schemes, even when both the spectrum and the eigenfunctions are only sightly modified. This is demonstrated for the generalization of a STIRAP scheme that has recently been implemented in optical waveguide structures. Here the question how an additional absorption in either the initial or the target waveguide influences the transfer property of the scheme is addressed. It is found that the scheme breaks down for small values of the absorption at a relatively sharp threshold, which can be estimated by simple analytical arguments.Comment: 8 pages, 7 figures, revised and extende

Pro and Con, A Complete Investigation of the Sunday School Question Viewed from a Bible Standpoint

In the first third of the twentieth century a significant debate was held among Churches of Christ concerning the propriety of employing Sunday Schools to teach the Bible in congregational settings. Trott and Clark\u27s tract is an early summary of the arguments.https://digitalcommons.acu.edu/crs_books/1012/thumbnail.jp

Calculations of time-dependent observables in non-Hermitian quantum mechanics: The problem and a possible solution

The solutions of the time independent Schrodinger equation for non-Hermitian (NH) Hamiltonians have been extensively studied and calculated in many different fields of physics by using L^2 methods that originally have been developed for the calculations of bound states. The existing non-Hermitian formalism breaks down when dealing with wavepackets(WP). An open question is how time dependent expectation values can be calculated when the Hamiltonian is NH ? Using the F-product formalism, which was recently proposed, [J. Phys. Chem., 107, 7181 (2003)] we calculate the time dependent expectation values of different observable quantities for a simple well known study test case model Hamiltonian. We carry out a comparison between these results with those obtained from conventional(i.e., Hermitian) quantum mechanics (QM) calculations. The remarkable agreement between these results emphasizes the fact that in the NH-QM, unlike standard QM, there is no need to split the entire space into two regions; i.e., the interaction region and its surrounding. Our results open a door for a type of WP propagation calculations within the NH-QM formalism that until now were impossible.Comment: 20 pages, 5 Postscript figures. To be Published in Physical Review

Patterns of antimicrobial use in the neurosurgical ward of Kenyatta National Hospital

Background: Antibiotics in neurosurgery are used for prophylaxis and treatment of already established infection.  Guidelines state that prophylactic antibiotics should be given for up to 24 hours. For treatment of already established infections, empiric therapy with intravenous antibiotics for four to eight weeks is indicated. Studies have shown no distinction between antibiotic use for prophylaxis and treatment of established infection in neurosurgery. Objectives: To identify antibiotic use patterns and medication errors and their association with development of surgical site infections. Methods: A prospective cohort study involving adult neurosurgical patients was carried out at Kenyatta National Hospital, between April 2015 and July 2015. Patient demographic data as well as data on surgical procedures carried out, antibiotics used and medication errors was collected. Descriptive data analysis was done for all variables. To test for association between antibiotic use patterns and development of surgical site infections, the Fischer exact Chi square test was used. Results: Out of the 84 participants recruited in the study, 87.2% (n=68) used antibiotics. Ceftriaxone was the most commonly used (63.7%, n= 44), followed by metronidazole (40.4%, n=23).  Medication errors that were noted involved inappropriate choice and use of antibiotics. There was no distinction between use of antibiotics for prophylaxis and treatment of infection. There was no statistically significant association between patterns of antibiotic use and development of surgical site infection. Conclusion: Antibiotic use patterns do not affect the incidence of neurosurgical site infections. Prescribing errors of various types were prominent. An antibiotic use protocol should guide antimicrobial selection and use in neurosurgery. Key words: antibiotic, prophylaxis, medication error