GEO debris and interplanetary dust: fluxes and charging behavior

In September 1996, a dust/debris detector: GORID was launched into the geostationary (GEO) region as a piggyback instrument on the Russian Express-2 telecommunications spacecraft. The instrument began its normal operation in April 1997 and ended its mission in July 2002. The goal of this work was to use GORID's particle data to identify and separate the space debris to interplanetary dust particles (IDPs) in GEO, to more finely determine the instrument's measurement characteristics and to derive impact fluxes. While the physical characteristics of the GORID impacts alone are insufficient for a reliable distinction between debris and interplanetary dust, the temporal behavior of the impacts are strong enough indicators to separate the populations based on clustering. Non-cluster events are predominantly interplanetary, while cluster events are debris. The GORID mean flux distributions (at mass thresholds which are impact speed dependent) for IDPs, corrected for dead time, are 1.35x10^{-4} m^{-2} s^{-1} using a mean detection rate: 0.54 d^{-1}, and for space debris are 6.1x10^{-4} m^{-2} s^{-1} using a mean detection rate: 2.5 d^{-1}. Beta-meteoroids were not detected. Clusters could be a closely-packed debris cloud or a particle breaking up due to electrostatic fragmentation after high charging.Comment: * Comments: 6 pages, 4 postscript figures, in Dust in Planetary Systems 2005, Krueger, H. and Graps, A. eds., ESA Publications, SP in press (2006). For high resolution version, see: http://www.mpi-hd.mpg.de/dustgroup/~graps/dips2005/GrapsetalDIPS2005.pd

Gevolgen ontkoppeling slachtpremies voor de vleeskalversector

Dit rapport geeft de mogelijke gevolgen aan van ontkoppeling van de slachtpremie voor de kalfs- en vleessector in Nederland. Of ontkoppeling zal leiden tot een aanzienlijke vermindering van de productie is sterk afhankelijk van de externe omstandigheden, de voorwaarden die zullen worden gesteld en de reactie van de kalverintegratie

Arginylation-Dependent Neural Crest Cell Migration Is Essential for Mouse Development

Coordinated cell migration during development is crucial for morphogenesis and largely relies on cells of the neural crest lineage that migrate over long distances to give rise to organs and tissues throughout the body. Recent studies of protein arginylation implicated this poorly understood posttranslational modification in the functioning of actin cytoskeleton and in cell migration in culture. Knockout of arginyltransferase (Ate1) in mice leads to embryonic lethality and severe heart defects that are reminiscent of cell migration–dependent phenotypes seen in other mouse models. To test the hypothesis that arginylation regulates cell migration during morphogenesis, we produced Wnt1-Cre Ate1 conditional knockout mice (Wnt1-Ate1), with Ate1 deletion in the neural crest cells driven by Wnt1 promoter. Wnt1-Ate1 mice die at birth and in the first 2–3 weeks after birth with severe breathing problems and with growth and behavioral retardation. Wnt1-Ate1 pups have prominent defects, including short palate and altered opening to the nasopharynx, and cranial defects that likely contribute to the abnormal breathing and early death. Analysis of neural crest cell movement patterns in situ and cell motility in culture shows an overall delay in the migration of Ate1 knockout cells that is likely regulated by intracellular mechanisms rather than extracellular signaling events. Taken together, our data suggest that arginylation plays a general role in the migration of the neural crest cells in development by regulating the molecular machinery that underlies cell migration through tissues and organs during morphogenesis

Large-scale structure around the Fornax-Eridanus complex

Aims. Our objectives are to map the filamentary network around the Fornax-Eridanus complex and probe the influence of the local environment on galaxy morphology.Methods. We employed the novel machine-learning tool, named, 1-Dimensional, Recovery, Extraction, and Analysis of Manifolds (1-DREAM) to detect and model filaments around the Fornax cluster. We then used the morphology-density relation of galaxies to examine the variation in the galaxies’ morphology with respect to their distance from the central axis of the detected filaments.Results. We detected 27 filaments that vary in length and galaxy-number density around the Fornax-Eridanus complex. We find that 81% of galaxies in our catalogue belong to filaments and 19% of galaxies are located outside filaments. The filaments around the Fornax-Eridanus complex showcase a variety of environments: some filaments encompass groups and clusters, while others are only inhabited by galaxies in pristine filamentary environments. In this context, we reveal a well-known structure, namely: the Fornax Wall, which passes through the Dorado group, Fornax cluster, and Eridanus supergroup. With regard to the morphology of galaxies, we find that early-type galaxies (ETGs) populate high-density filaments and high-density regions of the Fornax Wall. Furthermore, the fraction of the ETG-population decreases as the distance to the central axis of the filament increases. The fraction of late-type galaxies (LTGs; 8%) is lower than that of ETGs (12%) at 0.5 Mpc/h from the filament spine. Of the total galaxy population in filaments around the Fornax-Eridanus complex, ∼7% are ETGs and ∼24% are LTGs located in pristine environments of filaments, while ∼27% are ETGs and ∼42% are LTGs in groups and clusters within filaments. Among the galaxies in the filamentary network around the Fornax-Eridanus complex, 44% of them belong to the Fornax Wall.Conclusions. This study reveals the cosmic web around the Fornax cluster, which exhibits a variety of filamentary environments. With this, our research asserts that filamentary environments are heterogeneous in nature. When investigating the role of the environment on galaxy morphology, it is essential to consider both the local number-density and a galaxy’s proximity to the filament spine (i.e. the filament core). Within this framework, we ascribe the observed morphological segregation in the Fornax Wall to the pre-processing of galaxies among groups embedded in it

A New Framework for Understanding Memories and Preference for Music

What can musical memories tell us about preference, and what can musical preferences tell us about memory? In this article we contrast the two perspectives using a dialogic conversation, drawing on insights brought into relief at the recent Music and Lifetime Memories conference. We use dialogue to present two different bodies of relevant background literature and theory and consider their overlaps, interactions, and contradictions in depth. We then compare our two different approaches to the same dataset – the Desert Island Discs archive – which provide complementary perspectives and insights. We interpret each other’s analyses from our own perspectives, and finally conclude with reflections on future directions for the field