Wikipedia as an encyclopaedia of life

In his 2003 essay E O Wilson outlined his vision for an “encyclopaedia of life” comprising “an electronic page for each species of organism on Earth”, each page containing “the scientific name of the species, a pictorial or genomic presentation of the primary type specimen on which its name is based, and a summary of its diagnostic traits.” Although the “quiet revolution” in biodiversity informatics has generated numerous online resources, including some directly inspired by Wilson's essay (e.g., "http://ispecies.org":http://ispecies.org, "http://www.eol.org":http://www.eol.org), we are still some way from the goal of having available online all relevant information about a species, such as its taxonomy, evolutionary history, genomics, morphology, ecology, and behaviour. While the biodiversity community has been developing a plethora of databases, some with overlapping goals and duplicated content, Wikipedia has been slowly growing to the point where it now has over 100,000 pages on biological taxa. My goal in this essay is to explore the idea that, largely independent of the efforts of biodiversity informatics and well-funded international efforts, Wikipedia ("http://en.wikipedia.org/wiki/Main_Page":http://en.wikipedia.org/wiki/Main_Page) has emerged as potentially the best platform for fulfilling E O Wilson’s vision

Nitrogen Isotopes in Silicon Carbide: Stellar Nucleosynthesis?

Nitrogen in presolar SiC varies over a wide range of concentrations and is typically ^(14)N-rich relative to solar N, consistent with ^(15)N being consumed during CNO processing in stellar envelopes [e.g., 1]. Although C is also heavily processed in the envelopes [1], no clear isotopic correlation exists between C and N [e.g., 2], making N compositions difficult to interpret. Although the same general N features are seen in SiC from many meteorites, clear differences between meteorites have also been observed. In particular, Murchison SiC appears to have systematically higher ^(15)N/^(14)N ratios than Orgueil SiC [2,3]. Among ISN-poor SiC grains for both meteorites, ^(15)N/^(14)N and ^(28)Si/^(l4)N exhibit a positive correlation (Fig. 1)

Feasibility of Iodine and Bromine Analysis in Genesis Solar Wind Collectors

Comparison of elemental abundances in sun, meteorites and earth provides understanding of the formation and evolution of the solar system. Yet, the majority of the solar system abundances are based on meteoritic values [1–6]. Here we report an attempt to estimate a feasibility of direct measurements of iodine and bromine in the GENESIS solar wind Aluminum on Sapphire collector (AloS) using neutron induced conversions: ^(127)I(n,γβ)^(128)Xe, ^(79)Br(n,γβ)^(80)Kr and ^(81)Br(n,γβ)^(82)Kr

Europium valence state distributions in equilibrated ordinary chondrites

It has been recognized for 30 years that the presence of Eu anomalies in REE patterns is due to the presence of divalent Eu, unique among the REE. However, it has not previously been possible to infer quantitative Eu^(+2)/Eu^(+3) ratios in natural samples. We have used ion probe data for lithophile trace elements for the phases in equilibrated ordinary chondrites [Guareiia (H6), Marion (L6) and St. Sevérin (LL6)] to perform mass-balance calculations that yield relatively precise Eu^(+2)/Eu^(+3) ratios

Potential climatic transitions with profound impact on Europe

We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the ‘tipping’ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. <br/

Injection of Radioactivities into the Forming Solar System

Meteorite studies have revealed the presence of short-lived radioactivities in the early solar system. The current data suggests that the origin of at least some of the radioactivities requires contribution from recent nucleosynthesis at a stellar site. This sets a strict time limit on the time available for the formation of the solar system and argues for the theory of the triggered origin of the solar system. According to this scenario, the formation of our planetary system was initiated by the impact of an interstellar shock wave on a molecular cloud core. The shock wave originated from a nearby explosive stellar event and carried with it radioactivities produced in the stellar source. In addition to triggering the collapse of the molecular cloud core, the shock wave also deposited some of the freshly synthesized radioactivities into the collapsing system. The radioactivities were then incorporated into the first solar system solids, in this manner leaving a record of the event in the meteoritic material. The viability of the scenario can be investigated through numerical simulations studying the processes involved in mixing shock wave material into the collapsing system. The high-resolution calculations presented here show that injection occurs through Rayleigh-Taylor instabilities, the injection efficiency is approximately 10%, and temporal and spatial heterogeneities in the abundances of the radioactivities existed at the time of their arrival in the forming solar system.Comment: 13 pages, including 3 figures. Better-quality figures available at http://www.public.asu.edu/~hvanhal/pubs