Durham University

About: Durham University is a education organization based out in Durham, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 39385 authors who have published 82311 publications receiving 3110994 citations. The organization is also known as: University of Durham & Gallery of Durham University.

Effect of fatigue on knee kinetics and kinematics in stop-jump tasks.

Abstract: BackgroundAltered motor control strategies in landing and jumping maneuvers are a potential mechanism of noncontact anterior cruciate ligament injury. There are biomechanical differences between male and female athletes in the landing phase of stop-jump tasks. Fatigue is a risk factor in musculoskeletal injuries.HypothesisLower extremity muscle fatigue alters the knee kinetics and kinematics during the landing phase of 3 stop-jump tasks and increases an athlete's risk of anterior cruciate ligament injury.Study DesignControlled laboratory study.MethodsThree-dimensional videography and force plate data were collected for 20 recreational athletes (10 male and 10 female athletes) performing 3 stop-jump tasks before and after completing a fatigue exercise. Knee joint angles and resultant forces and moments were calculated.ResultsBoth male and female subjects had significantly increased peak proximal tibial anterior shear forces (P =. 01), increased valgus moments (P =. 03), and decreased knee flexion angles (P...

Television food advertising to children: a global perspective.

Abstract: Objectives. We compared television food advertising to children in several countries.Methods. We undertook a collaboration among 13 research groups in Australia, Asia, Western Europe, and North and South America. Each group recorded programming for 2 weekdays and 2 weekend days between 6:00 and 22:00, for the 3 channels most watched by children, between October 2007 and March 2008. We classified food advertisements as core (nutrient dense, low in energy), noncore (high in undesirable nutrients or energy, as defined by dietary standards), or miscellaneous. We also categorized thematic content (promotional characters and premiums).Results. Food advertisements composed 11% to 29% of advertisements. Noncore foods were featured in 53% to 87% of food advertisements, and the rate of noncore food advertising was higher during children's peak viewing times. Most food advertisements containing persuasive marketing were for noncore products.Conclusions. Across all sampled countries, children were exposed to high vol...

A White Paper on keV sterile neutrino Dark Matter

Abstract: We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved—cosmology, astrophysics, nuclear, and particle physics—in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos.

Virulence and competitive ability in genetically diverse malaria infections

Abstract: Explaining parasite virulence is a great challenge for evolutionary biology. Intuitively, parasites that depend on their hosts for their survival should be benign to their hosts, yet many parasites cause harm. One explanation for this is that within-host competition favors virulence, with more virulent strains having a competitive advantage in genetically diverse infections. This idea, which is well supported in theory, remains untested empirically. Here we provide evidence that within-host competition does indeed select for high parasite virulence. We examine the rodent malaria Plasmodium chabaudi in laboratory mice, a parasite–host system in which virulence can be easily monitored and competing strains quantified by using strain-specific real-time PCR. As predicted, we found a strong relationship between parasite virulence and competitive ability, so that more virulent strains have a competitive advantage in mixed-strain infections. In transmission experiments, we found that the strain composition of the parasite populations in mosquitoes was directly correlated with the composition of the blood-stage parasite population. Thus, the outcome of within-host competition determined relative transmission success. Our results imply that within-host competition is a major factor driving the evolution of virulence and can explain why many parasites harm their hosts.