A5012439893- Dust and Plasma Wave Phenomena
- Ionosphere and magnetosphere dynamics
- Primate Behavior and Ecology
- Plasma Diagnostics and Applications
- Magnetic confinement fusion research
- Wildlife Ecology and Conservation
- Solar and Space Plasma Dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Animal Vocal Communication and Behavior
- Earthquake Detection and Analysis
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Animal Behavior and Reproduction
- Nonlinear Dynamics and Pattern Formation
- Particle Dynamics in Fluid Flows
- Human-Animal Interaction Studies
- Chaos control and synchronization
- Plasma Applications and Diagnostics
- Marine animal studies overview
- GNSS positioning and interference
- Quantum chaos and dynamical systems
- Quantum, superfluid, helium dynamics
- Mass Spectrometry Techniques and Applications
- Species Distribution and Climate Change
University College London
2020-2025
Max Planck Institute for Evolutionary Anthropology
2023-2025
Tanzania National Parks
2018-2025
University of California, San Diego
2011-2022
Kiel University
2011-2021
Liverpool John Moores University
2015-2021
Fachhochschule Kiel
2001-2021
University of California, Davis
2021
George Washington University
2021
Hudson Institute
2021
Measurements of the melting transition a Coulomb crystal consisting dust particles immersed in an rf parallel plate discharge helium were performed. The is shown to be solid at higher gas pressure (120 Pa) and low power (10--20 W). Reducing or increasing leads fluid states ensemble. Even gaslike are observed pressures about 40 Pa. attributed effective particle temperature. phase compared with one-component-plasma Yukawa models, basic predictions theories for two-dimensional melting....
Abstract Large brains and behavioural innovation are positively correlated, species-specific traits, associated with the flexibility animals need for adapting to seasonal unpredictable habitats. Similar ecological challenges would have been important drivers throughout human evolution. However, studies examining influence of environmental variability on within-species diversity lacking despite critical assumption that population diversification precedes genetic divergence speciation. Here,...
More than just numbers We often frame negative human impacts on animal species in terms of individuals reduced or regions from which are absent. However, activities likely affecting more complex ways these figures can capture. Kühl et al. studied behavioral and cultural diversity our closest relative, the chimpanzee. They found that human-mediated disturbance is reducing traits. Human influence thus goes well beyond simple loss populations species, leading to change even where persist....
The screening of dust particles immersed in the sheath a parallel plate rf discharge helium is studied by excitation waves linear chain arrangement. are excited radiation pressure modulated laser beam. measured dispersion relation compared with one-dimensional lattice wave to obtain shielding length. Dust acoustic not compatible relation.
Charged dust particulates, forming a layered crystal in the electrode sheath of rf discharge, are known to show vertical alignment and an onset characteristic oscillations below threshold neutral gas density. Here forces on particulates due formation positive space-charge clouds particles calculated from Monte Carlo calculations ion motion sheath. The shown be attractive nonreciprocal for different layers. From results analytical lattice model is derived that quantitatively explains...
First experimental investigations of spherical three-dimensional plasma crystals consisting hundreds or thousands micrometer-sized polymer particles suspended in a radio-frequency gas discharge are described. These "Coulomb balls" not subject to the formation dust-free regions (voids) and have an unusual structure nested crystalline shells. While small systems solid phase, large show melting effects.
The electrostatic interaction of a system two single dust particles in plasma-sheath environment with flowing ions has been investigated quantitatively. It is shown that attractive net ``binding'' forces between the negatively charged exist, leading to formation molecule. By laser manipulation particles, it demonstrated attraction asymmetric such way acts only on one particles. Moreover, can be reversibly changed and repulsion.
The plasma crystal formed by monodisperse particles trapped in the sheath of an rf discharge is known to show vertically aligned structures. Here, oscillations are found below a threshold value gas density as precursor melting transition. Attractive forces due formation positive space-charge region upper particle calculated from Monte Carlo simulations ion trajectories sheath. alignment well explained simple model based on asymmetry forces.
Abstract The study of the archaeological remains fossil hominins must rely on reconstructions to elucidate behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, tool use among living primates has illuminated behaviours are also amenable examination, permitting direct observations leading artefacts assemblages be incorporated. Here, we describe newly discovered tool-use accumulation sites wild chimpanzees reminiscent human cairns. In addition data...
ABSTRACT Simian immunodeficiency virus of chimpanzees (SIVcpz) has a significant negative impact on the health, reproduction, and life span chimpanzees, yet prevalence distribution this in wild-living populations are still only poorly understood. Here, we show that savanna who live ecologically marginal habitats at 10- to 50-fold lower population densities than forest can be infected with SIVcpz high rates. Fecal samples were collected from nonhabituated eastern ( Pan troglodytes...
How an animal moves through its environment directly impacts survival, reproduction, and thus biological fitness. A basic measure describing how individual (or group) travels is Day Path Length (DPL), i.e., the distance travelled in a 24-hour period. Here, we investigate ecological determinants of baboon (Papio spp.) troop DPL movements at local continental scales.At scale explore annual mean for 47 troops across 23 different populations, updating classic study by Dunbar (Behav Ecol...
How populations adapt to their environment is a fundamental question in biology. Yet, we know surprisingly little about this process, especially for endangered species, such as nonhuman great apes. Chimpanzees, our closest living relatives, are particularly notable because they inhabit diverse habitats, from rainforest woodland-savannah. Whether genetic adaptation facilitates habitat diversity remains unknown, despite it having wide implications evolutionary biology and conservation. By...
ABSTRACT Ongoing ecosystem change and biodiversity decline across the Afrotropics call for tools to monitor state of or elements extensive spatial temporal scales. We assessed relationships in co‐occurrence patterns between great apes other medium large‐bodied mammals evaluate whether ape abundance serves as a proxy mammal diversity broad used camera trap footage recorded at 22 research sites, each known harbor population chimpanzees, some additionally gorillas, 12 sub‐Saharan African...
Monodisperse electrically charged particulates (9.4 mu m diameter) are trapped in the sheath of an argon RF parallel plate discharge. The form Coulomb crystals consisting horizontal hexagonal layers. A method for determination charge on particles is demonstrated that uses response to a modulation electrode bias. Charges about three five thousand elementary units measured. commonly applied orbital motion limited (OML) charging model leads charges higher than measured values. strong coupling...
The plasma crystal is shown to exhibit a nonequilibrium two-step phase transition due particle heating by ion streaming motion in the sheath. In nonlinear model, energy increase an induced instability found be separated from melting transition. melts at much higher than expected classical models. This behavior explained preferred destabilization of short-wavelength modes crystal.
In this review, a systematic overview of dynamical processes in complex (dusty) plasmas is given. Complex consist electrons, ions, neutrals, and microparticles nanometre to micrometre size, which are responsible for the unusual properties kind plasmas, such as formation liquid or solid phases at strong electrostatic coupling. The examples represent progress field within last five years mostly cases were chosen, experimental results could be compared with theory where phenomenon has...
Small three-dimensional strongly coupled charged particles in a spherical confinement potential arrange themselves nested shell structure. By means of experiments, computer simulations and theoretical analysis, it is shown that their structural properties depend on the type interparticle forces. Using an isotropic Yukawa interaction, quantitative agreement for radii occupation obtained.