The history is full of amazing people who showed us what you can do if you don’t give up. These are stories of failure, struggle and success. One example is Bernard J.S. Cahill (1866–1944). The paper “An account of a new land map op the world”, which he published in 1909, describes his struggles on the way to improve the projection of the world on a map. Back then, one famous map projection was the Mercator projection. It is based on a linear grid representing the longitudes and latitudes. That was helpful for navigation on the sea, but resulted in wrong projections of land forms. “Every map of the world must be a compromise, and in every map something must be sacrificed in order to lay a spherical superficies on a flat plane.” Because of the parallel latitudes, the poles are enlarged to the same size as the equator and the forms of the continents are exaggerated and distorted. Cahill, however, wanted a map which projected the forms of the continents without rupture or distortion. It should be a map not for navigators, but for geographers and scientists in general. Cahill worked eagerly for this idea and created a map which served his needs, when he had to face a stroke of fate: ”Then came the great earthquake and fire of San Francisco (April 18, 1906), and my maps and diagrams were all burned along with every- thing else I possessed, both in my office and in my home.” His work was gone, and he had to start again from the beginning. “Within a year I was back at the problem, which I approached this time in a more scientific spirit.” He calculated and tried many different ways of mapping the land of the world and it was worth it: Cahill invented the octahedral butterfly map. His concept of plotting the world in a series of eight triangular planes enabled a projection of the landforms without rupture or major distortion. And even better: Cahills projection method showed such a high accuracy that it was the base for the more recent (1975) Cahill–Keyes projection. That is a story of success, isn't it? An account of a new land map op the world.
Bernard J.S. Cahill The Scottish Geographical Magazine 25.9 (1909): 449-469
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Different magnetic materials can be found in the crust of the earth. However, just lodestones have the ability to behave like a magnet. The fact that lodestones were the base of the first compasses, is still hidden in their name “lode”(=course)-stone. In 1994, electron microscopy revealed the secret structure of lodestones. It was known before that lodestones are made of oxidized magnetide (Fe3O4), but not all oxidized magnetide was lodestone. The secret of lodestones lay on an intergrowth of magnetite (Fe3O4) and maghemite (Fe2O3). Nevertheless, this structure does not explain the origin of the charge. In 1999, Peter Wasilewski and Günther Kletetschka dealed with the question how lodestones gets charged. They calculated the magnetic field which would be needed to charge a lodestone and came up with an interesting hypothesis: Lodestones are charged up by lightning strikes. Experiments with “controlled” bolts showed that the magnetic field created by bolts can increase the remanent magnetization (= magnetization which remains) in lodestones. That would also explain why lodestones are found “near the surface and not in deep mines”. "Lodestone: Natures only permanent magnet ‐ What it is and how it gets charged."
Peter Wasilewski and Günther Kletetschka Geophysical research letters 26.15 (1999): 2275-2278. Air quality is a main problem of the civilization. Therefore, models predicting air pollution become more and more important. And this is quite easy. Let Aurora work together with albatross, and you will get good predictions. Of course I am referring to the paper of Carolien Beckx et al. (2009) and ALBATROSS and AURORA are models: A Learning-Based Transportation Oriented Simulation System and Air quality modelling in Urban Regions using an Optimal Resolution Approach. ALBATROSS is an activity-based model which predicts people's travel behaviour and the resulting vehicle emissions. It is based on approximately 10,000 person-day activity-diaries of Dutch. The predictions of vehicle emissions can be used as input for the air quality model AURORA. As “prognostic 3-dimensional Eulerian model of the atmosphere”, AURORA predicts how air pollutants (gas and particla) are transported in the air, including physical changes and chemical reactions which generate new pollutants. Using meterological parameters like wind, temperature, humidity, precipitation, radiation,…, AURORA calculates 3-dimensional concentration fields for different pollutants. Beckx et al. (2009) tested this model combination by comparing the model predictions for three different pollutants with real air quality data measured in different stations all over the Netherlands. Inside the country, the agreement between modelled and observed concentrations varied between the different pollutants but was sufficient for all of them. The only problems are the borders of the Netherlands, maybe because of wrong calculation of the contribution of foreign traffic. Maybe they underestimated how many people like to visit the Netherlands? The contribution of activity-based transport models to air quality modelling: a validation of the ALBATROSS–AURORA model chain
Carolien Beckx, et al. Science of the Total Environment 407.12 (2009): 3814-3822 Everybody knows this feeling: you are looking for a specific word. It is floating in your mind but you can not grab it. You know what it means, are able to recall synonyms. Sometimes you also have a clue how it sounds like… the initial letter, the syllable length. Although you are not able to immediately find the right word you are looking for you know immediately if a word somebody else suggests is the one you are looking for or if it’s not. This mental state in which you can’t recall a familiar word but words of similar form and meaning is called "tip of the tongue" (TOT) phenomenon. In 1966 Roger Brown and David McNeill published a paper in which they tried to analyze the TOT phenomenon. They read the definition of uncommon English words to fifty-six Harvard and Radcliffe undergraduates and asked them to recall the word fitting to the definition before reading the target word. Sometimes this procedures created TOT states in single subjects were the person was aware of a word (right or wrong) fitting to the definition. In this case they asked the person to write down what he knows about the word: initial letter, number of syllables, words with similar meaning or words with similar sound. EXAMPLE The process of recalling parts and attributes of a word but not the complete word itself is called "generic recall". The study showed that indeed people in the TOT state can recall with significant success the number of syllables and the initial letter in a target word. Words with similar sound were most likely representing the right letters in the right position in the beginning and the end of the word, supporting the known order of attention in word reading: As long as the first and the last letter are in the right position people are most likely able to read the word even if the other letters in the middle of the word are unsorted. Looking at the “sound like” words which the persons listed up in the TOT state showed that there was a correlation between the similarity of the “sound like” words to the target words and the chance to find the target word on its own. Roger Brown and David McNeill explain this fact by describing the word memory as a keysort cards system. Each word we know is described by cards describing various features of the word. The cards are punched for various features of the words they describe. Therefore, even if the card with the target word is missing some letters or is unreadable, we are able to recall some facts about the word which then can help us to fill the gaps in the target card until we find the word. The “tip of the tongue” phenomenon
Roger Brown and David McNeill Journal of verbal learning and verbal behavior 5.4 (1966): 325-337 The neotropic ecozone covers a small tropical part of North America and complete South America. The birds there are called neotropical birds and the flavescent warbler ( Basileuterus flaveolus) is one of them. It inhabits forests and forest edges as well as woody savanna and desert vegetation and eats mainly beetles. In 2005, Charles Duca and Miguel Â. Marini published a paper about the territory size of the flavescent warbler in South Brazil. Previous studies suggest a correlation between territory size and habitat structure. The ‘ecological trap hypothesis’ predicts that on the one hand more insects are accessible for the birds at the forrest edge. On the other hand the nest predator rate is higher at the forest edges. However, the study of Duca and Marini does not support this hypothesis. Neither the insect biomass nor the nest predation vary significant between forest interior and forest edge. The territory size also does not depend on the distance to the forest border and vary little during the season. Nevertheless, the flavescent warbler seems to prefer living on the edge. “Males defending territories closer to the forest edge were more successful in pairing than those in the forest interior.” Territory size of the Flavescent Warbler, Basileuterus flaveolus (Passeriformes, Emberizidae),
in a forest fragment in Southeastern Brazil Charles Duca and Miguel Â. Marini Lundiana, Belo Horizonte 6.1 (2005): 29-33 For decades, the people thought that aggression is based on low self-esteem. The paper of Roy F. Baumeister, Brad J. Bushman, and W. Keith Campbell published in 2000, challenges this low-self-esteem theory. Just image a person with low self esteem: this person is unsure and confused about its own position which makes them emotionally labile and shy. This person is not a person which is risking a confrontation, isn’t it? Now imagine a violent person. Assuming that you will not be motivated to start a conflict on yourself when there is no chance for you to win it, the aggressive person is confident of itself. It has a strong sense of personal superiority. Does this means that the low-self-esteem theory is wrong? It seems likely. Does it means it is high self esteem which makes people aggressive? No. Of course there are also people with high self esteem which are not aggressive at all. So what makes people aggressive? There are studies about instability of self-esteem as well as narcissism as base of aggressive behaviour. However, you can not say that a narcissistic person is an aggressive person. The highly favourable self-view is just a risk factor for aggressive behaviour against persons who challenge this view. Therefore, “threatened egotism, rather than low self-esteem, is the most explosive recipe for violence.” Self-Esteem, Narcissism, and Aggression: Does Violence Result From Low Self-Esteem or From Threatened Egotism?
Roy F. Baumeister, Brad J. Bushman, and W. Keith Campbell Current directions in psychological science 9.1 (2000): 26-29. We do it every day… we like it when it is the coffee in the morning and don’t like it when it is a sweating person in the full subway. Our olfactory system detects all the pleasant and unpleasant odours of our environment for 24h every day of our life. However, what seems so simple in our daily life is quite hard to rebuild with electronic-chemical devices, so called electronic noses. In order to smell something, different kinds of odourant molecules needs to be detected and their relative amounts decide about the flavour they are creating. Julian W. Gardner and Philip N. Bartlett published 1994 a review about the history electronic noses. The first electronic noses were already build in the early 60’s but it needed further 20 years in order to improve an intelligent design for odour detection and the first conference for electronic noses was held in 1990. In the human nose, G-binding proteins act as chemosensory receptors in the olfactory cells. The binding of the odour molecules with the receptors triggers a second-messenger signal cascade which ends up in the creation of action potential which are transferred by nerve cells to the brain. In the electronic nose, inorganic semiconducting materials such as oxides and catalytic metals have been used as sensors for odour molecules. For example, the electronic nose of Wilkens and Hatman (1964) was based on redox reactions of the odourants at an electrode. The sensors are enough for odour detection, but for odour classification, the electric signal created by the receptors needs to be analysed by the usage of pattern recognition (PARC) engine or supervised learning artificial networking technique. The main problems in building electronic noses are the conflicts between sensitivity, selectivity and life duration. The sensitivity of the sensors depends on environmental properties such as temperature and humidity. Moreover, it is difficult to distinguish between the different odour molecules and reactive species decrease the life time of the sensors. However, the receptor cells in the human nose also have a low sensitivity, low specificity and short life duration (22 days). It is the subsequent neuronal processing which increases the sensitivity (by three orders magnitude) and offers us the probability to distingue between several thousand odours. So the solution for the electronic nose problems is not located in the odour sensors but the computation network behind it. A brief history of electronic noses
Julian W. Gardner and Philip N. Bartlett Sensors and Actuators B: Chemical 18.1 (1994): 210-211. When you look at a leaf you may think about photosynthesis, seasons, plant diseases,…, but have you ever thought about what is living on and in the leaf? The term phyllosphere describes leaves as habitat for different microorganisms. Fungi, yeasts, bacteria and bacteriophages can be found in and on leaves. Their interplay with the plant can be beneficial or pathological, dependend on plant and bacterial genetics and physical aspects like the weather. Leaves as habitat are no difficult habitat if you compare the temperature maximum and minimum or radiation with other environments at which you find microorganisms (e.g. hot springs). The difficulties of this habitat are the (rapid) day-night changes of temperature, radiation, rain and wind, and the short existence of the habitat of several weeks in annual plants because of seasons. Nevertheless, many different bacteria can be found on leaves and the dominant species may change with plant age or with environmental conditions. One example of leaf-living bacteria is Pseudomonas syringae and it has a real paradoxial way of rewarding its own success. In 2000, Susan S. Hirano and Christen D. Upper published a review about P.syringae with the focus on its role in the leaf ecosystem. P.syringae is a known pathogen which creates lesions. Besides the lesions, P. syringae is known for its ability to nucleate supercooled water to form ice which damages the plant. The probabilty of both, the lesion formation and ice-nucleation, increases with increasing population size. That means that if the leaf offers good conditions for successful reproduction for P.syringae, it destroys its own habitat by lesion formation and ice-nucleation. That is paradoxial! Therefore, the paper claims that these overpopulations are just accidents. “The real function of P.syringae is to live on healthy leaves.” So maybe there is just a sensitive interplay between the host plant and the bacteria which normally restricts the population size. “Only when conditions become unusually favorable and population sizes of the bacteria become too large does the entire system crash, to the detriment of both host and bacteria.” The question is why this happens. Why the plant can't prohibit this process and creates a favorable habitat for its enemy. And why has P.syringae no feedback mechanism, which prevents the destruction of its own habitat? Maybe P.syringae just doesn’t care as it immigrates by the plant seeds and by the wind… Bacteria in the Leaf Ecosystem with Emphasis onPseudomonas syringae—a Pathogen, Ice Nucleus, and Epiphyte.
Susan S. Hirano, and Christen D. Upper Microbiology and molecular biology reviews 64.3 (2000): 624-653. |
IdeaI love to increase my general science knowledge by reading papers from different fields of science. Here I share some of them. Archiv
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