1,039 research outputs found
ANALYSIS OF HUMAN MOTION WITH METHODS FROM MACHINE LEARNING
Usually, predefined kinematic parameters are investigated in biomechanical studies of human motion. In recent years, techniques of machine learning have been added to this field of research (Chau, 2001). In this study different dimension reduction methods like Principal Component Analysis (PCA) and Fourier Transformation (FT) are investigated as an alternative to common biomechanical approaches in motion analysis
Viking Age garden plants from southern Scandinavia: diversity, taphonomy and cultural aspects
Plant finds recovered from archaeological sites in southern Scandinavia dated to the Viking Age reflect the diversity of useful plants that were cultivated and collected. This review presents the results of 14 investigations of deposits that are dated between AD 775 and 1050. The site types are categorized as agrarian, urban, military and burials. Garden plants are unevenly distributed, as the greatest diversity is recorded in features from urban contexts. We argue that taphonomic processes played an important role in the picture displayed. Archaeobotanical research results from neighbouring regions suggest that Viking Age horticulture has its roots in older traditions, and that the spectrum of garden plants is influenced by central and north-western European horticultural customs, which were to a great extent shaped by Roman occupation
Development of Acoustic Sensors for the ANTARES Experiment
In order to study the possibility of acoustic detection of ultra-high energy
neutrinos in water, our group is planning to deploy and operate an array of
acoustic sensors using the ANTARES Neutrino telescope in the Mediterranean Sea.
Therefore, acoustic sensor hardware has to be developed which is both capable
of operation under the hostile conditions of the deep sea and at the same time
provides the high sensitivity necessary to detect the weak pressure signals
resulting from the neutrino's interaction in water. In this paper, two
different approaches to building such sensors, as well as performance studies
in the laboratory and in situ, are presented.Comment: 5 pages, 3 figures. Proceedings of the ARENA 2005 Worksho
Nutrient and virtual water flow analysis for Tamale, Ghana and Ouagadougou, Burkina Faso
Nutrients and virtual water in the form of food and other organic goods are transported from the rural hinterland to urban centres. In particular in developing countries, poor waste management in growing cities and the potential to recover nutrients and water for agricultural production have raised interest in quantifying these flows. What are the quantities of organic materials that enter and leave a city? Which materials carry the most important nutrient and virtual water flows? Where does nutrient and water depletion take place? This study has been conducted within the UrbanFoodPlus project (www.urbanfood plus.org) to assess organic material flows and their quantitative nutrient and virtual water contribution for the cities of Tamale in Ghana and Ouagadougou in Burkina Faso. Matter flows (unprocessed foodstuff, firewood, fodder, non-timber forest products, etc.) from regional, national and international sources were systematically recorded at all roads leading to Tamale and Ouagadougo. Organic matter from urban sources aand stocks were captured at major markets. The survey has been conducted within two years covering the peak (November) and lean season (April) for six days in a row. The study maps the virtual water and nutrient transfers of different types of traded food products and other organic goods. The results will improve our understanding of the urban metabolism, and may support the development of standardised methodologies for assessing virtual water and nutrient flows
Differing views - can chimpanzees do level 2 perspective-taking?
We gratefully acknowledge financial support by the German National Academic Foundation.Although chimpanzees understand what others may see, it is unclear if they understand how others see things (Level 2 perspective-taking). We investigated whether chimpanzees can predict the behavior of a conspecific which is holding a mistaken perspective that differs from their own. The subject competed with a conspecific over two food sticks. While the subject could see that both were the same size, to the competitor one appeared bigger than the other. In a previously established game, the competitor chose one stick in private first and the subject chose thereafter, without knowing which of the sticks was gone. Chimpanzees and 6-year-old children chose the ‘riskier’ stick (that looked bigger to the competitor) significantly less in the game than in a nonsocial control. Children chose randomly in the control, thus showing Level 2 perspective-taking skills; in contrast, chimpanzees had a preference for the ‘riskier’ stick here, rendering it possible that they attributed their own preference to the competitor to predict her choice. We thus run a follow-up in which chimpanzees did not have a preference in the control. Now they also chose randomly in the game. We conclude that chimpanzees solved the task by attributing their own preference to the other, while children truly understood the other’s mistaken perspective.Publisher PDFPeer reviewe
Integration of Acoustic Neutrino Detection Methods into ANTARES
The ANTARES Neutrino Telescope is a water Cherenkov detector currently under
construction in the Mediterranean Sea. It is also designed to serve as a
platform for investigations of the deep-sea environment. In this context, the
ANTARES group at the University of Erlangen will integrate acoustic sensors
within the infrastructure of the experiment. With this dedicated setup, tests
of acoustic particle detection methods and deep-sea acoustic background studies
shall be performed. The aim of this project is to evaluate the feasibility of a
future acoustic neutrino telescope in the deep sea operating in the ultra-high
energy regime. In these proceedings, the implementation of the project is
described in the context of the premises and challenges set by the physics of
acoustic particle detection and the integration into an existing
infrastructure.Comment: 6 pages, 5 figures, to appear in the proceedings of the International
ARENA Workshop, May 28-30th, 2006, University of Northumbri
Tensile Properties and Microstructures of Laser-Formed Ti-6Al-4V
The room temperature tensile properties of Ti-6Al-4V alloy prepared under two different processing routes were evaluated and compared. One group of samples was prepared by conventional casting-forging-rolling into flat plates. The other group was prepared by using Triton\u27s Laser Free-Form Fabrication (LF3)(TM) processes, i.e., a laser was used to melt pre-alloyed powders of the required metallic composition as they were dropped onto a moveable substrate programmed to move in such a manner as to form a solid alloy plate. Five populations of Ti-6Al-4V were evaluated: a standard wrought form, an as-deposited form, a machined as-deposited form, a heat-treated as-deposited form, and a machined as-deposited and heat-treated form. The poorest mechanical properties occurred with the rough surfaces, likely due to existing microcracks and stress concentrations. The LF3 (TM) as-deposited material had mechanical properties comparable to, if not higher than, the mechanical properties of the wrought material. Further evaluations of the laser-formed material for complex spacecraft piece parts were warranted, specifically in regards to improving the surface finish of the materials
Serotonin tranporter methylation and response to cognitive behaviour therapy in children with anxiety disorders
Anxiety disorders that are the most commonly occurring psychiatric disorders in childhood, are associated with a range of social and educational impairments and often continue into adulthood. Cognitive behaviour therapy (CBT) is an effective treatment option for the majority of cases, although up to 35-45% of children do not achieve remission. Recent research suggests that some genetic variants may be associated with a more beneficial response to psychological therapy. Epigenetic mechanisms such as DNA methylation work at the interface between genetic and environmental influences. Furthermore, epigenetic alterations at the serotonin transporter (SERT) promoter region have been associated with environmental influences such as stressful life experiences. In this study, we measured DNA methylation upstream of SERT in 116 children with an anxiety disorder, before and after receiving CBT. Change during treatment in percentage DNA methylation was significantly different in treatment responders vs nonresponders. This effect was driven by one CpG site in particular, at which responders increased in methylation, whereas nonresponders showed a decrease in DNA methylation. This is the first study to demonstrate differences in SERT methylation change in association with response to a purely psychological therapy. These findings confirm that biological changes occur alongside changes in symptomatology following a psychological therapy such as CBT
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