Where have all the forests gone? Quantifying pantropical deforestation drivers

Deforestation across the tropics continues to be a major source of greenhouse gas emissions and the largest threat to biodiversity on land. With strengthened commitments to reduce deforestation from countries and companies alike, it is crucial that renewed investments for reducing deforestation be guided by a sound understanding of what drives deforestation. This thesis gives a comprehensive picture of the amount of deforestation and concomitant carbon emissions driven by the expansion of agricultural commodities across the tropics and its link to international trade. The included papers show that pasture and a handful of crops drive a large share of the deforestation resulting in the expansion of productive agriculture. The main demand for these commodities is domestic consumption; even so, imports of food commodities associated with deforestation can still constitute a large part of the consumer countries’ carbon emissions due to consumption (e.g., in the EU). This thesis contributes empirical evidence relating to forest transition theories by showing that many countries with increasing forest cover tend to import products associated with deforestation elsewhere, thereby offsetting around one-third of their forest gains. The thesis also introduces a conceptual distinction between two categories of agriculture-driven deforestation, based on whether it results in productive agricultural land or not. Though almost all deforestation is agriculture-driven, one-third to one-half of agriculture-driven deforestation occurs without the expansion of productive agricultural land. Instead, it may be due to several potential mechanisms, such as land speculation, tenure issues, or fires. Put together, these results indicate that it is crucial that policies to curb deforestation go beyond focusing only on trade in specific commodities, to help foster concerted action on rural development, territorial governance, and land-use planning. This thesis also highlights key evidence gaps on the links between deforestation and agriculture: (i) the attribution of deforestation to specific commodities currently often relies on coarse or outdated data, (ii) there is a need for improved data on deforestation trends, and (iii) our understanding of deforestation drivers is systematically poorer for dry forests and Africa

Students compete in European Union Science Olympiad 2010

In April 2010, young students from 21 countries competed in EUSO - the European Union Science Olympiad. Each country sent two teams of three students to an experimental science competition. The first day, the teams helped an alien find water on Earth, and the second day, the solved a criminal case

A guilty satisfaction: detective fiction and the reader

The purpose of this thesis is to explore the reasons why readers choose to read detective fiction. Taking Thomas De Quincey’s satirical identification of the aesthetic quality of murder, I look at Edgar Allan Poe’s detective fiction to find a non-satiric version of the same argument that emphasises the balancing quality of the ethical to the aesthetic. W.H. Auden’s essay “The Guilty Vicarage” offers an argument concerning the reader’s position in relation to these opposite components. I explore the ways in which Auden’s arguments build into Freud’s understanding of guilt, daydreams, the moral conscience, jokes, the uncanny and the death drive, and how these can be applied to the genre to help illustrate the reader’s experience. Concurrent to this I offer an analysis of how the parallel developments in literary theory, particularly those of Barthes and Shklovsky, can be incorporated to enrich the understanding of these Freudian positions within the modern reader’s experience. It is my intention to open up a field of study within the genre that differs from the traditional Marxist approach. Particular emphasis is placed on the role of the experience of pleasure found when moments of commonality between the aesthetic and the ethical are reached– how these are often unsatisfactory– necessitating a repetition of the literary experience. It is my argument that such an approach to the reader’s position within the genre has not been explored in such a detailed fashion, centring as it does upon the active role of guilt in pleasure felt by the reader as the motivation to repeat. To illustrate that this is an argument that is applicable to different historical phases of detective fiction the study undertakes analysis of the following authors: Arthur Conan Doyle, Wilkie Collins, Agatha Christie, Raymond Chandler, Graham Greene and John Fowles

Student Investigations of Forces in a Roller Coaster Loop.

How does the experience of a riding in a roller coaster loop depend on your position in the train? This question has been investigated by first year engineering physics students, using multiple representations of force and motion. Theoretical considerations for a circular loop show that the differences between the forces on a rider in the front, middle or back of the train depend on the ratio between train length and radius of the loop, which can be estimated from a photograph. Numerical computations complement the analysis of a video clip, accelerometer data and measurements of time needed for the train to move over the highest point. A roller coaster ride gives striking examples of Newton’s laws applied to your own body, and demonstrates that the experience depends on the vector character of velocity and acceleration

Roller coaster loop shapes revisited

In 'Rollercoaster loop shapes', (Pendrill 2005 Phys. Educ. 40 517) the author started from the observation that although textbook loops are often circular, real rollercoaster loops are not. In this paper the mathematical description of various possible loop shapes, as well as their riding properties was discussed and also how a study of loop shapes can be used in physics education

Free fall and harmonic oscillations: Analyzing trampoline jumps

© 2015 IOP Publishing Ltd. Trampolines can be found in many gardens and also in some playgrounds. They offer an easily accessible vertical motion that includes free fall. In this work, the motion on a trampoline is modelled by assuming a linear relation between force and deflection, giving harmonic oscillations for small amplitudes. An expression for the cycle-time is obtained in terms of maximum normalized force from the trampoline and the harmonic frequency. A simple expression is obtained for the ratio between air-time and harmonic period, and the maximum g-factor. The results are compared to experimental results, including accelerometer data showing 7g during bounces on a small trampoline in an amusement park play area. Similar results are obtained on a larger garden trampoline, and even larger accelerations have been measured for gymnastic trampolines

Acceleration and rotation in a pendulum ride, measured using an iPhone 4

Many modern cell phones have built-in sensors that may be used as a resource for physics education. Amusement rides offer examples of many different types of motion, where the acceleration leads to forces experienced throughout the body. A comoving 3D-accelerometer gives an electronic measurement of the varying forces acting on the rider, but a complete description of a motion also requires measurement of the rotation around the three axes, as provided, for example, by the iPhone 4. Here we present and interpret accelerometer and gyroscope data that were collected on a rotary pendulum ri

Beyond velocity and acceleration: Jerk, snap and higher derivatives

© 2016 IOP Publishing Ltd. The higher derivatives of motion are rarely discussed in the teaching of classical mechanics of rigid bodies; nevertheless, we experience the effect not only of acceleration, but also of jerk and snap. In this paper we will discuss the third and higher order derivatives of displacement with respect to time, using the trampolines and theme park roller coasters to illustrate this concept. We will also discuss the effects on the human body of different types of acceleration, jerk, snap and higher derivatives, and how they can be used in physics education to further enhance the learning and thus the understanding of classical mechanics concepts

Vetenskapligt förhållningssätt i samhällsfrågor

Vetenskapliga frågor med samhällsrelevans är ofta mycket komplexa. En del är känt, en del är okänt. En förståelse för problemen kräver ofta djupa specialkunskaper inom många olika ämnen och ett samarbete mellan experter inom olika områden är därför väsentligt. Data kan ofta vara ofullständiga och kontrollerade experiment kan av olika skäl vara olämpliga eller omöjliga. Hur dessa frågor skall kunna presenteras på ett rimligt korrekt och begripligt sätt för allmänheten är naturligtvis inte en strikt naturvetenskaplig fråga, men naturvetare som skall arbeta med komplexa frågor behöver förståelse även för dessa aspekter

Teacher roles during amusement park visits – insights from observations, interviews and questionnaires

Amusement parks offer rich possibilities for physics learning, through observations and experiments that illustrate important physical principles and often involve the whole body. Amusement parks are also among the most popular school excursions, but very often the learning possibilities are underused. In this work we have studied different teacher roles and discuss how universities, parks or event managers can encourage and support teachers and schools in their efforts to make amusement park visits true learning experiences for their students