21,173 research outputs found
Locomotion in Biological Systems
No full textOne of the common properties of fauna is their ability to move (Dickinson, Farley et al.
2000). Most animals are capable of relocating their position, and locomotion is often a key
to survival. Animals forage, escape, and migrate. This is true not only for multi-cellular but
also for single cell organisms (Murphy, Drone et al. 1985). It is even the case for the
individual cells of a multi-cellular organism. The range of movements that I considered in this
thesis ranges from the micron scale, such as the movement of neutrophils, to hemispherical
scales, as in the case for the seasonal migration of birds and mammals. Moreover,
movements can be un-coordinated and solitary, such as the movements of some cancer cells
(Yamaguchi, Wyckoff et al. 2005), or they can be coordinated between several hundreds or
thousands of individuals (flocking birds or fish) (Feder 2007). The quantification of
movement gives important information about the underlying molecular processes in cells,
which encompasses the field of molecular biology, or the complex behavior of (groups of)
organisms, which encompasses the field of ethology.
My studies are governed by the overarching question regarding the characteristics and
driving forces of motion across several orders of magnitude. I investigated the locomotion
inside cells at the nanometer scale, locomotion of individual cells at the micron scale,
movements of single penguins inside a colony at the scale of centimeters to meters,
movements of whales at a scale up to several kilometers, and the possibility to study
movement of migratory and invasive species, at the scale of kilometers to tens of thousands
of kilometers (Figure 1).
The work presented in this thesis was performed in several phases; the first years
concentrated on the biophysical aspects of cell migration and traction generation (Metzner,
Raupach et al. 2007; Raupach, Zitterbart et al. 2007; Mierke, Kollmannsberger et al. 2008;
Mierke, Zitterbart et al. 2008; Rösel, Brábek et al. 2008; Oakes, Patel et al. 2009; Mierke,
Kollmannsberger et al. 2010); later, the focus switched to the macroscopic world, including a
15 month stay at Neumayer station, Antarctica, during which the idea of investigating the
collective dynamics of emperor penguins (Zitterbart, Wienecke et al. 2011) arose.
Subsequently, I investigated the local locomotion of whales in the presence of large ships
(Burkhardt, Kindermann et al. 2011) (i.e. RV Polarstern). This study required the
development of a technology to automatically detect whales (Zitterbart, Kindermann et al.
2011; Zitterbart, Kindermann et al. 2012). In parallel, I started a global biodiversity
assessment project (anymals+plants) to investigate the movement and distribution of animal
or plant populations, and to unveil trends in the spreading of species e.g. due to global
climate changes
2-D traction microscopy:Entwicklung eines Verfahrens zur Untersuchung von Adhaesion, Ausbreitung und Migration einzelner Zellen auf Oberflachen
No full textReport on Meteorological Research March 1, 1935 (m-1)
No full textThe object of the report was to elucidate in detail the various features of the research program in meteorology being carried on at the Daniel Guggenheim Airship Institute in Akron, Ohio. Mr. L. J. Fangman, of the U.S. Weather Bureau, was collaborating with the author in carrying out work such as a study of autographic records of the various meteorological elements during frontal passages with a view to the possible prediction of the intensity of the accompanying disturbance as it may affect the operation of aircraft and a study of atmospheric gustiness with a view to finding the dependence between frequency end amplitude of velocity fluctuations and the vertical temperature and velocity gradients
(Fourth) Report on Meteorological Activities at the DGAI (8-1-36)(Weather Bureau Copy)
No full textThis report is on the investigations of frontal phenomena at the Daniel Guggenheim Airship Institute in Akron, Ohio from January 1, 1935 through August 1, 1936. The investigation was carried out with the cooperation of the U.S. Bureau of Aeronautics, the U.S. Weather Bureau, the California Institute of Technology, and the Guggenheim Airship Institute. Mr. R.C. Robinson of the Weather Bureau cooperated with the author in carrying out the investigation. The object of the investigation was to determine the intensity of the atmospheric disturbances (i.e. rapidity of wind shift and gustiness) accompanying the passage of cold fronts, along with a study of the characteristics of the air masses involved and other features which might affect the intensity of the disturbance. The report treated thirty cold fronts which passed the station during 1935 to 1936
Archives and Images as Repositories of Time, Language, and Forms from the Past: A Conversation with Daniel Eisenberg
No full textDaniel Akech
No full textabstract: Daniel was a little boy when the war came to his village. He witnessed people being shot and running for shelter. There was no food or water so he drank urine and ate tree leaves.
“Lost Boys Found” is an ongoing, interdisciplinary project that is collecting, recording and archiving the oral histories of the Lost Boys/Girls of Sudan. The collection is a work-in-progress, seeking to record the oral history of as many Lost Boys/Girls as are willing, and will be used in a future book.Age: 24Region: Upper NileThis picture and bio was donated to the "Lost Boys Found" oral history project from The Arizona Lost Boys Cente
Daniel Emmett postcard
No full textPostcard of Daniel Emmett and his home in Mount Vernon, Ohio. Emmett is considered to be the author of the antebellum song "Dixie," written in 1859, which became the unofficial song of the Confederate soldiers during the American Civil War. He was born in Mount Vernon in 1815 and taught himself the fiddle, and later became associated with minstrel shows and helped to define that genre. Minstrel shows traveled around the United States, presenting skits and musical performances. Emmett also composed many other songs, including "Old Dan Tucker," "Turkey in the Straw," and "The Blue Tail Fly." He died in 1904
Daniel Jau Maper
No full textabstract: Daniel Jau Maper was herding cattle when Arabs attacked his village.
“Lost Boys Found” is an ongoing, interdisciplinary project that is collecting, recording and archiving the oral histories of the Lost Boys/Girls of Sudan. The collection is a work-in-progress, seeking to record the oral history of as many Lost Boys/Girls as are willing, and will be used in a future book.Age: 27Region: Upper NileThis picture and bio was donated to the "Lost Boys Found" oral history project from The Arizona Lost Boys Cente
Daniel A. Ngor
No full textWhen Daniel was five years old Arab soldiers attacked his village.
“Lost Boys Found” is an ongoing, interdisciplinary project that is collecting, recording and archiving the oral histories of the Lost Boys/Girls of Sudan. The collection is a work-in-progress, seeking to record the oral history of as many Lost Boys/Girls as are willing, and will be used in a future book.Age : 23Region: Upper NileThis picture and bio was donated to the "Lost Boys Found" oral history project from The Arizona Lost Boys Cente
Automatic detection and identification of whales using thermal and visual imaging techniques for cetacean censuses and marine mammal mitigation
No full textAUTOMATIC DETECTION AND IDENTIFICATION OF WHALES USING THERMAL AND VISUAL IMAGING TECHNIQUES FOR CETACEAN CENSUSES AND MARINE MAMMAL MITIGATION
Daniel P. Zitterbart, Sebastian Richter, Lars Kindermann, Olaf Boebel
For centuries, the spotting of a whale was the apex of days of tedious watch keeping. This skill – lost with the demise of commercial whaling - has recently regained significance, as it forms the basis for scientific cetacean censuses and mitigation efforts of navies and marine geophysical prospection, which both employ loud acoustic sources.
We designed, developed, tested and validated an automatic whale detection system (360°) based on a thermal imaging scanner. A coupled visual imaging system allows for identification of automatically detected whales without any marine mammal experts on board. It is capable of detection whales reliably in up to 5 km distance from the ship. Species identification is performed retrospective by a marine mammal expert using high resolution images.
We show that this system detects about twice as many whales as visual observers during the same time, and is less effected by environmental conditions like sea-state and wind speed. Moreover is works day and night. It outperforms an alerted observer in terms of number of detections and is a significant step forward in cetacean detection technologies
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