On Multiplicative Sidon Sets

Fix integers $b>a\geq1$ with $g:=\gcd(a,b)$. A set $S\subseteq\mathbb{N}$ is \emph{$\{a,b\}$-multiplicative} if $ax\neq by$ for all $x,y\in S$. For all $n$, we determine an $\{a,b\}$-multiplicative set with maximum cardinality in $[n]$, and conclude that the maximum density of an $\{a,b\}$-multiplicative set is $\frac{b}{b+g}$. For $A, B \subseteq \mathbb{N}$, a set $S\subseteq\mathbb{N}$ is \emph{$\{A,B\}$-multiplicative} if $ax=by$ implies $a = b$ and $x = y$ for all $a\in A$ and $b\in B$, and $x,y\in S$. For $1 < a < b < c$ and $a, b, c$ coprime, we give an O(1) time algorithm to approximate the maximum density of an $\{\{a\},\{b,c\}\}$-multiplicative set to arbitrary given precision

From UHSL to UHMLG: the evolution of a group for health librarians in higher education

In 2007 the University Health Sciences Librarians Group (UHSL) merged with the University Medical Schools Librarians Group (UMSLG) to form the University Health and Medical Librarians Group (UHMLG). This paper traces the course of health librarianship in the UK which led to this event, from the perspective of the UHSL

From locked cupboard to University Library: libraries for nurses in the UK after 1955

This paper presents an outline of the history of library provision for nurses in the second half of the twentieth century. The few libraries for nurses that existed in the fifties were usually attached to Schools of Nursing and often run by volunteers, clerical assistants or nurse tutors. In an organisation where the emphasis was on training and skills development rather than education and reflection and the prime aim was maintaining a health service with limited resources, provision of books and journals for theoretical learning had a low priority. In turn nurses gained a reputation as people who did not read. In order to respond to problems of staff morale, recruitment and retention, in the last decade of the century attempts were made to make nursing more attractive by giving pre-registration learners student status, encouraging a research-based approach to learning and absorbing it into higher education. However many of the problems facing libraries would not be quickly resolved. An attempt will be made to explain library provision for nurses with reference to the generation of knowledge in nursing and its relationship to library based knowledge. This will touch on the role and status of the nurse, the nature of her work and training, the ideological foundations of the nursing profession and the impact that these have on the provision of library services

Large magnetoresistance in the antiferromagnetic semi-metal NdSb

There has been considerable interest in topological semi-metals that exhibit extreme magnetoresistance (XMR). These have included materials lacking inversion symmetry such as TaAs, as well Dirac semi-metals such as Cd3As2. However, it was reported recently that LaSb and LaBi also exhibit XMR, even though the rock-salt structure of these materials has inversion symmetry, and the band-structure calculations do not show a Dirac dispersion in the bulk. Here, we present magnetoresistance and specific heat measurements on NdSb, which is isostructural with LaSb. NdSb has an antiferromagnetic groundstate, and in analogy with the lanthanum monopnictides, is expected to be a topologically non-trivial semi-metal. We show that NdSb has an XMR of 10^4 %, even within the AFM state, illustrating that XMR can occur independently of the absence of time reversal symmetry breaking in zero magnetic field. The persistence of XMR in a magnetic system offers promise of new functionality when combining topological matter with electronic correlations. We also find that in an applied magnetic field below the Neel temperature there is a first order transition, consistent with evidence from previous neutron scattering work.Comment: 5 pages, 6 figure

ACUTE CARDIOVASCULAR RESPONSES TO NOVEL COMBINATIONS OF RESISTANCE AND AEROBIC EXERCISE

Cardiovascular disease (CVD) is the leading cause of death globally. One of the most effective forms of prevention and treatment is physical activity. However, recent studies have suggested that resistance exercise can increase arterial stiffness. Maintaining adequate strength is critical for performing activities of daily living, occupational-related tasks, and sport movements. The purpose of this project was to determine if novel combinations of resistance and aerobic exercise could offer musculoskeletal benefits without adverse cardiovascular consequences. In Study 1, we examined the effect of order (i.e. aerobic before resistance, or resistance before aerobic) on arterial stiffness when combining these exercise modes in a single training session. In Study 2, we compared the effects of acute eccentric and concentric arm cycling on central and peripheral arterial stiffness. Eccentric arm cycling is a unique combination of resistance and aerobic exercise. We hypothesized that these novel combinations of resistance and aerobic exercise would not cause arterial stiffening as observed in resistance exercise alone. In Study 1, we concluded performing resistance before aerobic to be the more beneficial exercise order in terms of arterial stiffness. In Study 2, we found that eccentric arm cycling reduces arterial stiffness in the arm, but not centrally. Collectively, our results suggest that the key to reducing the negative effects of resistance exercise on arterial function is to combine it with aerobic exercise, either first within a single session or simultaneously