445,754 research outputs found
Evolution of malaria virulence in cross-generation transmission through selective immune pressure
Theoretical arguments and some mathematical models of host-parasite coevolution (e.g. [1- 6]) suggest host immunity as the driving source for the evolution of parasite virulence. Imperfect vaccines in particular, can play the role and recent work [7] sets to test these ideas experimentally, using the mouse malaria model, Plasmodium chabaudi. To this end the authors evolve parasite lines in immunized and nonimmunized (“naïve”) mice using serial passage of infected blood samples. They find parasite lines evolved in immunized mice become more virulent than those evolved in naive mice. Furthermore, this feature persisted even when the evolved strains were transmitted through mosquitoes. 
Here we develop a mathematical model of parasite dynamics that qualitatively reproduces the experimental results of [7]. Our model accounts for the basic in-host processes: (i) production and depletion of red blood cells (RBC); (ii) immune-modulated parasite growth/ replication, (iii) immune stimulation and clearing of parasite. Besides we introduce multiple parasite strains with variable levels of virulence, and allow random mutations during replication process. The virulence is represented by a single parameter – immune stimulation threshold. So more virulent strains have higher “tolerance levels”, hence increased RBC depletion (anemia). 
Numeric simulations with our model exhibit, as in [7] the overall evolution of virulence in serial passage of parasite strains, and its enhancement through partial (imperfect) immunization
What We Find in the Sea
Personal essay in which the author recounts his struggle to come to terms with his lack of grief over his grandfather’s death
Broadening access to earth science information for education in the UK
The presentation describes strategies for enhancing earth science teaching through inspiring role-play and long-term experiments. Over the past decade there has been a growing concern that earth sciences are often poorly served in UK schools. In parallel with this there has been a general decline in the number of students choosing science. The government's response has been a number of initiatives designed to stimulate interest in scientific careers and enhance the learning experience. Over the same period, UK and European government alongside popular campaigns have encouraged the release of national datasets for educational purposes. The British Geological Survey (BGS) has an international reputation in the delivery of data for professional geologists and is now building a portfolio of projects based on free, convenient access to digital data alongside face-to-face contact with inspirational role models with the aim of introducing exciting, relevant science to schools. The UK-wide School Seismology Project provides a specially designed instrument records earthquakes from anywhere on the globe and the data may be shared through a web portal. Schools receive training, sponsorship and practical support. Students benefit from the experience of collecting unique data and opportunities to report their findings via local press and TV. Sister projects are running in Ireland and Africa. STEM Ambassadors provide a wide range of in-school support, from simple experiments to careers advice and mentoring. Our most requested activities include 'Seconds from Catastrophe?' and 'Quarry or Not?'. In these, students take on the roles of scientists, government officials and residents and vigorously debate, respectively, the issues involved in planning an emergency response to a volcanic eruption and the environmental impacts of the extractive industry. Real data are analysed and an important feature is that the facilitators have genuine experience of the scenarios
The Legality of University-Conducted Dormitory Searches for Internal Disciplinary Purposes
The issue examined is whether those unique characteristics of the university environment that have led to the development of a judicially-sanctioned general regulatory power will automatically render a warrantless disciplinary search reasonable within the terms of the fourth amendment. (LBH
The Missing Basics & Other Philosophical Reflections for the Transformation of Engineering Education
The paper starts by reflecting on what senior engineering students don't know how to do when they confront a real-world project in an industrially sponsored senior design project. Seven, largely qualitatively, skills are found to be lacking: questioning, labeling, qualitatively modeling, decomposing, measuring, ideating, and communicating. These skills, some of the most important critical and creative thinking skills in the arsenal of modern civilization, are termed "the missing basics" and contrasted with what engineering faculty usually call "the basics." The paper critically examines the term "the basics" and other terms that are conceptual hurdles to fundamental reassessment of engineering education at this time. The paper concludes that the engineering academy is stuck in a Kuhnian paradigm born in the cold war, that the reflexive belief in the superiority of math, science, and engineering science to the exclusion of other topics is not itself scientific, and that the use of tired code words is not an argument or a rational defense of a paradigm that may have outlived its usefulness. The paper concludes by highlighting the role philosophy can play in clearing away the conceptual confusion, thereby permitting a more reasoned conversation on the needs of engineering education in our times
- …
