Computing the Mertens and Meissel-Mertens constants for sums over arithmetic progressions

We give explicit numerical values with 100 decimal digits for the Mertens constant involved in the asymptotic formula for $\sum\limits_{\substack{p\leq x p\equiv a \bmod{q}}}1/p$ and, as a by-product, for the Meissel-Mertens constant defined as $\sum_{p\equiv a \bmod{q}} (\log(1-1/p)+1/p)$, for $q \in \{3$, ..., $100\}$ and $(q, a) = 1$.Comment: 12 pages, 6 table

A series solution and a fast algorithm for the inversion of the spherical mean Radon transform

An explicit series solution is proposed for the inversion of the spherical mean Radon transform. Such an inversion is required in problems of thermo- and photo- acoustic tomography. Closed-form inversion formulae are currently known only for the case when the centers of the integration spheres lie on a sphere surrounding the support of the unknown function, or on certain unbounded surfaces. Our approach results in an explicit series solution for any closed measuring surface surrounding a region for which the eigenfunctions of the Dirichlet Laplacian are explicitly known - such as, for example, cube, finite cylinder, half-sphere etc. In addition, we present a fast reconstruction algorithm applicable in the case when the detectors (the centers of the integration spheres) lie on a surface of a cube. This algorithm reconsrtucts 3-D images thousands times faster than backprojection-type methods

Notes on the Position of the Individuals in a Group of Nileus vigilans Found at Elgin, Iowa

David Dale Owen made note more than fifty years ago of the multitudes of fragmentary specimens of Asaphus iowensis in an exposure at the junction of Otter Creek with the Turkey River at Elgin, Iowa. From then on, that locality has been classic trilobite territory. The most abundant species to be found entire there now, if good trilobites can be said to be abundant anywhere, is Nileus vigilans, which occurs both enrolled and more or less straightened in form

A Terrace Formation in the Turkey River Valley, in Fayette County, Iowa

The Turkey River flows, in the lower part of its course, through the driftless area in Fayette County, through wide bottom lands. These are usually a half-mile, sometimes a mile or more in width, showing considerable progress in base-leveling

Investigating people: a qualitative analysis of the search behaviours of open-source intelligence analysts

The Internet and the World Wide Web have become integral parts of the lives of many modern individuals, enabling almost instantaneous communication, sharing and broadcasting of thoughts, feelings and opinions. Much of this information is publicly facing, and as such, it can be utilised in a multitude of online investigations, ranging from employee vetting and credit checking to counter-terrorism and fraud prevention/detection. However, the search needs and behaviours of these investigators are not well documented in the literature. In order to address this gap, an in-depth qualitative study was carried out in cooperation with a leading investigation company. The research contribution is an initial identification of Open-Source Intelligence investigator search behaviours, the procedures and practices that they undertake, along with an overview of the difficulties and challenges that they encounter as part of their domain. This lays the foundation for future research in to the varied domain of Open-Source Intelligence gathering

Penicillin-resistant pneumococci—implications for management of community-acquired pneumonia and meningitis

AbstractPenicillin-nonsusceptible Streptococcus pneumoniae isolates have become increasingly prevalent worldwide. They are well-known agents of community-acquired infections such as otitis media, pneumonia and bacterial meningitis. Therapy of pneumococcal infections is made difficult by the emergence and spread of bacterial resistance to penicillin and other beta-lactams, as well as other antimicrobials such as macrolides. This article reviews current concepts of epidemiology and the implications of penicillin-nonsusceptible pneumococci for management of community-acquired pneumonia and meningitis

EFFECTS OF AN ANGLED STARTING BLOCK ON SPRINT START KINEMATICS

The sprint start mechanics have changed over the years with the invention of the starting blocks. The most recent modification of the starting block developed by Gill Athletics was to create an outward angle of the foot position in the block in order to match the .28 rad. (16 deg.) oblique axis of the ankle. This study examined the effects of an outward angled foot position in a starting block prototype on the first four steps during sprinting kinematics