Subdivision Shell Elements with Anisotropic Growth

A thin shell finite element approach based on Loop's subdivision surfaces is proposed, capable of dealing with large deformations and anisotropic growth. To this end, the Kirchhoff-Love theory of thin shells is derived and extended to allow for arbitrary in-plane growth. The simplicity and computational efficiency of the subdivision thin shell elements is outstanding, which is demonstrated on a few standard loading benchmarks. With this powerful tool at hand, we demonstrate the broad range of possible applications by numerical solution of several growth scenarios, ranging from the uniform growth of a sphere, to boundary instabilities induced by large anisotropic growth. Finally, it is shown that the problem of a slowly and uniformly growing sheet confined in a fixed hollow sphere is equivalent to the inverse process where a sheet of fixed size is slowly crumpled in a shrinking hollow sphere in the frictionless, quasi-static, elastic limit.Comment: 20 pages, 12 figures, 1 tabl

Caught in the act: Implications for the increasing abundance of mafic enclaves during the eruption of the Soufriere Hills Volcano, Montserrat

An exceptional opportunity to sample several large blocks sourced from the same region of the growing Soufrière Hills lava dome has documented a significant increase in the presence of mafic enclaves in the host andesite during the course of a long-lived eruptive episode with several phases. In 1997 (Phase I) mafic inclusions comprised ~1 volume percent of erupted material; in 2007 (Phase III) deposits their volumetric abundance increased to 5–7 percent. A broader range of geochemically distinctive types occurs amongst the 2007 enclaves. Crystal-poor enclaves generally have the least evolved (basaltic) compositions; porphyritic enclaves represent compositions intermediate between basaltic and andesitic compositions. The absence of porphyritic enclaves prior to Phase III magmatism at Soufrière Hills Volcano suggests that a mixing event occurred during the course of the current eruptive episode, providing direct evidence consistent with geophysical observations that the system is continuously re-invigorated from depth

COMPRENDIENDO LA DETECCIÓN DE METALES Y LA ARQUEOLOGÍA EN FINLANDIA

The use of the metal detector in archaeology, and the relationships between metal detecting enthusiasts and archaeologists, has been long discussed and analysed in different contexts. The tool itself is acknowledged to be a useful prospecting device for use in archaeological fieldwork, and yet it has often attracted controversy in academic and professional archaeologi- cal circles due to its popularity with artefact-hunting hobbyists. In this paper, we discuss the emerging trends of metal detector use in Finland. This includes what is known about the hobbyist metal detector enthusiasts and their motivations, the extent of collaboration (or clashes) with archaeologists, and the current and potential use of metal detectors within archaeological fieldwork."El uso de detectores de metales en arqueología, y la relación entre los aficionados a la detección de metales y los arqueólogos, ha sido ampliamente discutida y analizada en diferentes contextos. Se reconoce la utilidad de la propia herramienta como útil instrumento para la prospección en el trabajo de campo arqueológico, sin  embargo,  a  menudo  ha  atraído  contro- versia en círculos académicos y de arqueólogos profesionales debido a su popularidad con entusiastas de la búsqueda de objetos [arqueológicos].En este artículo, tratamos las emergentes tendencias en el uso de aparatos detectores de metales en Finlandia. Esto incluye qué se conoce sobre los usuarios no profesionales de los aparatos detectores de metales y sus motivaciones, el grado de colaboración (o conflictos) con los arqueólogos, y el actual y potencial uso de los detectores de metales dentro del trabajo de"campo arqueológico.

Hadron structure at small momentum transfer

Giving three examples, the form factors of the nucleon, the polarisability of the charged pion and the interference of the $S_{11}(1535)$ with the $D_{13}(1520)$ excitation of the nucleon in the $\eta p$-decay channel, it is argued that the hadron structure at low momentum transfer is highly significant for studying QCD.Comment: 7 pages, 9 figures. Contribution to the International School of Nuclear Physics, 29th Ccourse, "Quarks in Hadrons and Nuclei", Erice, Sicily, 16 - 24 September 200

The demographic drivers of local population dynamics in two rare migratory birds

The exchange of individuals among populations can have strong effects on the dynamics and persistence of a given population. Yet, estimation of immigration rates remains one of the greatest challenges for animal demographers. Little empirical knowledge exists about the effects of immigration on population dynamics. New integrated population models fitted using Bayesian methods enable simultaneous estimation of fecundity, survival and immigration, as well as the growth rate of a population of interest. We applied this novel analytical framework to the demography of two populations of long-distance migratory birds, hoopoe Upupa epops and wryneck Jynx torquilla, in a study area in south-western Switzerland. During 2002-2010, the hoopoe population increased annually by 11%, while the wryneck population remained fairly stable. Apparent juvenile and adult survival probability was nearly identical in both species, but fecundity and immigration were slightly higher in the hoopoe. Hoopoe population growth rate was strongly correlated with juvenile survival, fecundity and immigration, while that of wrynecks strongly correlated only with immigration. This indicates that demographic components impacting the arrival of new individuals into the populations were more important for their dynamics than demographic components affecting the loss of individuals. The finding that immigration plays a crucial role in the population growth rates of these two rare species emphasizes the need for a broad rather than local perspective for population studies, and the development of wide-scale conservation action

An introduction to Trends in Extreme Weather and Climate Events: Observations, Socioeconomic Impacts, Terrestrial Ecological Impacts, and Model Projections

Weather and climatic extremes can have serious and damaging effects on human society and infrastructure as well as on ecosystems and wildlife. Thus, they are usually the main focus of attention of the news media in reports on climate. There are some indications from observations concerning how climatic extremes may have changed in the past. Climate models show how they could change in the future either due to natural climate fluctuations or under conditions of greenhouse gas-induced warming. These observed and modeled changes relate directly to the understanding of socioeconomic and ecological impacts related to extremes.Integrative Biolog

Diverse viruses in deep-sea hydrothermal vent fluids have restricted dispersal across ocean basins

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Thomas, E., Anderson, R. E., Li, V., Rogan, L. J., & Huber, J. A. Diverse viruses in deep-sea hydrothermal vent fluids have restricted dispersal across ocean basins. Msystems, 6(3), (2021): e00068-21, https://doi.org/10.1128/mSystems.00068-21.In the ocean, viruses impact microbial mortality, regulate biogeochemical cycling, and alter the metabolic potential of microbial lineages. At deep-sea hydrothermal vents, abundant viruses infect a wide range of hosts among the archaea and bacteria that inhabit these dynamic habitats. However, little is known about viral diversity, host range, and biogeography across different vent ecosystems, which has important implications for how viruses manipulate microbial function and evolution. Here, we examined viral diversity, viral and host distribution, and virus-host interactions in microbial metagenomes generated from venting fluids from several vent sites within three different geochemically and geographically distinct hydrothermal systems: Piccard and Von Damm vent fields at the Mid-Cayman Rise in the Caribbean Sea, and at several vent sites within Axial Seamount in the Pacific Ocean. Analysis of viral sequences and clustered regularly interspaced short palindromic repeat (CRISPR) spacers revealed highly diverse viral assemblages and evidence of active infection. Network analysis revealed that viral host range was relatively narrow, with very few viruses infecting multiple microbial lineages. Viruses were largely endemic to individual vent sites, indicating restricted dispersal, and in some cases, viral assemblages persisted over time. Thus, we show that hydrothermal vent fluids are home to novel, diverse viral assemblages that are highly localized to specific regions and taxa.Funding for E.T. was provided by Carleton College. R.E.A. was supported by a NASA Postdoctoral Fellowship with the NASA Astrobiology Institute. This work was supported by a NASA Exobiology grant 80NSSC18K1076 to R.E.A. and J.A.H., a NASA Astrobiology Science and Technology for Exploring Planets (ASTEP) grant NNX-327 09AB75G, and a grant from Deep Carbon Observatory's Deep Life Initiative to J.A.H., the NSF Science and Technology Center for Dark Energy Biosphere Investigations (C-DEBI) to J.A.H., and the Gordon and Betty Moore Foundation grant GBMF3297 to J.A.H. Samples were collected from the Mid-Cayman Rise with the assistance of the captains and crew of the R/V Atlantis and R/V Falkor as well as ROVs Jason and Nereus. For Mid-Cayman Rise, ship and vehicle time in 2012 were supported by the NSF-OCE grant OCE-1061863 to Chris German and Jeff Seewald and in 2013 by the Schmidt Ocean Institute during cruise FX008-2013 aboard the R/V Falkor. Samples collected from Axial Seamount were collected with the assistance of the captains and crew of the R/V Falkor, R/V Thompson, and R/V Brown as well as the ROV ROPOS and Jason groups, and in 2013 the Schmidt Ocean Institute during cruise FK010-2013 aboard the R/V Falkor

Migration patterns of Hoopoe Upupa epop s and Wryneck Jynx torquilla: an analysis of European ring recoveries

For many bird species, recovery of ringed individuals remains the best source of information about their migrations. In this study, we analyzed the recoveries of ringed European Hoopoe (Upupa epops) and the Eurasian Wryneck (Jynx torquilla) from 1914 to 2005 from all European ringing schemes. The aim was to define general migration directions and to make inferences about the winter quarters, knowing that hardly any recoveries are available from sub-Saharan Africa. For the autumn migration, there is evidence of a migratory divide for the Hoopoe in Central Europe, at approximately 10-12°E. Autumn migration directions of Wrynecks gradually change from SW to SE depending on the longitude (west to east) of the ringing place. In both species, only a few recoveries were available indicating spring migration directions, but they showed similar migration axes as for autumn migration, and hence no evidence for loop-migration. Due to a paucity of recoveries on the African continent, we can make only limited inferences about wintering grounds: extrapolating migration directions are only indicative of the longitude of the wintering area. The directions of autumn migration indicate a typical pattern observed in European long-distance migrants: west-European Hoopoes and Wrynecks are likely to winter in western Africa, while central- and east-European birds probably winter more in the east. Due to the migratory divide, for the Hoopoe, this phenomenon is more pronounce

Understanding metal detecting and archaeology in Finland

The use of the metal detector in archaeology, and the relationships between metal detecting enthusiasts and archaeologists, has been long discussed and analysed in different contexts. The tool itself is acknowledged to be a useful prospecting device for use in archaeological fieldwork, and yet it has often attracted controversy in academic and professional archaeological circles due to its popularity with artefact-hunting hobbyists. I n this paper, we discuss the emerging trends of metal detector use in Finland. This includes what is known about the hobbyist metal detector enthusiasts and their motivations, the extent of collaboration (or clashes) with archaeologists, and the current and potential use of metal detectors within archaeological fieldwork.Peer reviewe