Effects of a novel bicycle saddle on symptoms and comfort in cyclists

Background. While the bicycle frame and other parts of the bicycle have undergone many improvements, the bicycle saddle has remained relatively unchanged since it was first designed more than 100 years ago. Given the number and range of cycling injuries believed to result from the saddle, this is surprising. This study investigated the effects of a novel bicycle saddle on saddle-related comfort and symptoms during cycling.Method. Eleven competitive or recreational cyclists, 6 females and 5 males, performed three 2-hour stationary cycle rides in the laboratory, using their personal bicycles. Ride 1 was performed using the standard bicycle saddle and rides 2 and 3 using the novel bicycle saddle. Subjects reported saddle comfort rating scores (SC) while using the different saddles. Subjects also completed a questionnaire evaluating saddle symptoms (SS) when using either the conventional or the novel bicycle saddle during daily cycling.Results. The most common saddle-related medical complaint with chronic use of the conventional saddle was painful pubic bones, with or without chafing. Others were severe chafing, saddle sores, chafing and back pain, and painful pubic bones associated with a loss of feeling in the pelvic area. The mean SS rating score during the 2-hour laboratory ride was significantly less for the novel saddle (11.6 ± 1.2 versus 19.1 ± 3.2 arbitrary units, P < 0.01). Similarly the mean SC score was significantly lower for the novel saddle (36.2 ± 10.5 v. 54.7 ± 11.2 arbitrary units). Values for both SC scores were similar for rides 2 and 3. On completion of the trial all subjects indicated that they would continue to use the novel saddle in preference to the conventional saddle. Three months later 9 subjects (82%) reported continued use of this saddle in preference to the conventional saddle.Conclusion. These results show conclusively that this novel bicycle saddle: (i) significantly reduced reported symptoms during daily cycling compared with the conventionally designed cycling saddle; (ii) significantly improved saddle comfort during 2-.hour cycles in the laboratory, such that (iii) when given the option the majority (82%) of the subjects chose to use this saddle 3 months later. Furthermore, the beneficial effects of the novel saddle were apparent during its first use, suggesting that the novel saddle is effective because the design is anatomically correct

Introduction

Cambridge Studies in Nineteenth-Century Literature and Culture No. 45Copyright © 2004 Cambridge University PressFor the Victorian reading public, periodicals played a far greater role than books in shaping their understanding of new discoveries and theories in science, technology and medicine. Such understandings were formed not merely by serious scientific articles, but also by glancing asides in political reports, fictional representations, or humorous attacks in comic magazines. Ranging across diverse forms of periodicals, from top-selling religious and juvenile magazines through to popular fiction-based periodicals, and from the campaigning 'new journalism' of the late century to the comic satire of Punch, this book explores the ways in which scientific ideas and developments were presented to a variety of Victorian audiences. In addition, it offers three case studies of the representation of particular areas of science: 'baby science', scientific biography, and electricity. This intriguing collaborative volume sheds light on issues relating to history and history of science, literature, book history, and cultural and media studies

The mixing of airborne contaminants by the repeated passage of people along a corridor

Abstract </jats:p

Invariant higher-order variational problems II

Motivated by applications in computational anatomy, we consider a second-order problem in the calculus of variations on object manifolds that are acted upon by Lie groups of smooth invertible transformations. This problem leads to solution curves known as Riemannian cubics on object manifolds that are endowed with normal metrics. The prime examples of such object manifolds are the symmetric spaces. We characterize the class of cubics on object manifolds that can be lifted horizontally to cubics on the group of transformations. Conversely, we show that certain types of non-horizontal geodesics on the group of transformations project to cubics. Finally, we apply second-order Lagrange--Poincar\'e reduction to the problem of Riemannian cubics on the group of transformations. This leads to a reduced form of the equations that reveals the obstruction for the projection of a cubic on a transformation group to again be a cubic on its object manifold.Comment: 40 pages, 1 figure. First version -- comments welcome

Avoid adding insult to injury – correct management of sick female endurance athletes

Objectives. To evaluate the efficacy of Ringer&#8217;s lactate, isotonic saline and hypertonic saline on the clinical and biochemical recovery of athletes with exercise-associated hyponatraemic encephalopathy caused by fluid overload.Methods. We retrospectively reviewed serial blood sodium concentrations (Na+) and qualitative signs of recovery and time to recovery in two healthy menstruant females hospitalised with dilutional exercise-associated hyponatraemic encephalopathy after withdrawal from the 2011 Comrades Marathon (89 km) and Argus Cycle Tour (109 km).Results. Improvements in blood Na+ did not occur with intravenous administration of Ringer&#8217;s lactate solution, but did occur with administration of isotonic and hypertonic saline. Qualitative improvements in mental status were not quantitatively related to the biochemical value of blood Na+ or subsequent return to normonatraemia.Conclusions. Hyponatraemia should be suspected in all female athletes presenting to the medical area of endurance races with vomiting, altered mental status and a history of high fluid intake. If a diagnosis of exercise-associated hyponatraemia with cerebral encephalopathy is confirmed, the treatment of choice is administration of an intravenous bolus of hypertonic saline. Administration of Ringer&#8217;s lactate should be discouraged, as this does not correct Na+ and appears to delay recovery

Coexistence of ferromagnetism and superconductivity in the hybrid ruthenate-cuprate compound RuSr_2GdCu_2O_8 studied by muon spin rotation (\mu SR) and DC-magnetization

We have investigated the magnetic and the superconducting properties of the hybrid ruthenate-cuprate compound RuSr_{2}GdCu_{2}O_{8} by means of zero-field muon spin rotation- (ZF-$\mu$SR) and DC magnetization measurements. The DC-magnetisation data establish that this material exhibits ferromagnetic order of the Ru-moments ($\mu (Ru) \approx 1 \mu_{B}$) below T_{Curie} = 133 K and becomes superconducting at a much lower temperature T_c = 16 K. The ZF-$\mu$SR experiments indicate that the ferromagnetic phase is homogeneous on a microscopic scale and accounts for most of the sample volume. They also suggest that the magnetic order is not significantly modified at the onset of superconductivity.Comment: improved version submitted to Phys. Rev.

Composition profiles of InAs–GaAs quantum dots determined by medium-energy ion scattering

The composition profile along the [001] growth direction of low-growth-rate InAs–GaAs quantum dots (QDs) has been determined using medium-energy ion scattering (MEIS). A linear profile of In concentration from 100% In at the top of the QDs to 20% at their base provides the best fit to MEIS energy spectra