In studying logic, one learns how to establish that a conclusion follows from a set of premises. Those arguments that exhibit one of the valid forms of the deductive system under study are valid. There may be questions about what forms are exhibited by various arguments - Is this English conditional (or any other) really truth-functional? Is this disjunction really inclusive? Are the English predicates used with uniform meaning? - but none of these problems undermine the claim that if an argument exhibits a valid form of a system for deductive logic, then that argument is valid.

When we move on to study invalidity, however, we find that the situation is not parallel. Every argument is an instance of some invalid argument forms, and we cannot say that every instance of every invalid form is invalid.

I want to present some evidence that facts about de re attitudes or causal facts are important in the explanation of actions. In particular, I will argue that an attempt by Ernest Sosa and Mark Pastin [4] to give a scheme for explaining intentional actions fails. By adding either de re or causal locutions we can devise a more adequate schema for explaining action, but their analysis had been designed to eliminate de re locutions from explanations of intentional action. Showing the failure of their analysis does not, of course, show that de re or causal elements are required in these explanations, since it does not rule out the possibility of alternative explanatory schemes. But the centrality of de re or causal elements is supported by the inadequacy of their attempts to dispense with them.

Design ideation is a critical early step in any design process and especially challenging for novice designers. This paper introduces the “Systematic Brainstorming Ideation (SBI)” method that, as part of a wider design ideation process, improves the range and number of design concepts generated by novice designers. In this paper we give a brief introduction to the design ideation method to set a context for SBI and then introduce SBI in more detail. Evaluation experiments with 101 novice designers, based in UK and South Korea, are reported. Results indicate a 30% improvement in the number of design concepts generated.

Astronomical observations of Centaurs and trans-Neptunian objects (TNOs) yield two characteristic features – near-infrared (NIR) reflectance and low geometric albedo. The first feature apparently originates due to complex organic material on their surfaces, but the origin of the material contributing to low albedo is not well understood. Titan tholins synthesized to simulate aerosols in the atmosphere of Saturn's moon Titan have also been used for simulating the NIR reflectances of several Centaurs and TNOs. Here, we report novel detections of large polycyclic aromatic hydrocarbons, nanoscopic soot aggregates and cauliflower-like graphite within Titan tholins. We put forth a proof of concept stating the surfaces of Centaurs and TNOs may perhaps comprise of highly ‘carbonized’ complex organic material, analogous to the tholins we investigated. Such material would apparently be capable of contributing to the NIR reflectances and to the low geometric albedos simultaneously.

The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- to nearly 6000-fold increase in annual streamflow. Lake levels decreased slightly during the cold summer, and increased between 0.54 and 1.01 m during the warm summer, effectively erasing the prior 14 years of lake level lowering in a period of three months. Lake level rise during the warm summer was shown to be strongly associated with and increase in degree days above freezing at higher elevations. We suggest that strong summer down-valley winds may have been responsible for the generation of large glacial lakes during the Last Glacial Maximum when ice core records recorded annual temperatures significantly colder than present.

Extended abstract of a paper presented at Microscopy and Microanalysis 2005 in Honolulu, Hawaii, USA, July 31--August 4, 2005

Bone is a composite material composed of collagen, carbonated apatite mineral, water, and other non-collagenous proteins. The bone structure inside human body is under constant remodelling. The mechanical properties of bone and their dynamic changes during remodelling are crucial to the health and quality of life.

In this study, the elastic and viscoelastic properties of a 73 year-old female cortical bone were investigated at the lamellar level. This was realized by a nanoindentation technique equipped with dynamic loading function. 325 indentations were made in individual Haversian systems and interstitial bone at both dry and wet condition, and under two different loading frequencies. The results showed no statistically significant differences in elastic modulus between Haversian systems and interstitial bone. There were no systematic differences in modulus across the cortex except for a slight drop at the periosteal site. The lamellar structure of both Haversian system and interstitial bone is viscoelastic with water playing a significant role to the properties. When dry bone is re-hydrated, elastic modulus decreases and loss tangent increases.

Martian Meteorite ALH84001 contains four unusual features which have been interpreted as possible signatures of relic biogenic activity. After six years of intense study by the world's scientific community, the current status of the biogenic hypothesis is reviewed and shown to still be valid. Furthermore additional features have been observed in two younger Martian meteorites. The strongest argument for possible evidence of biogenic activity within the ALH84001 meteorite is the presence of truncated hexa-octahedral magnetite crystals which are only known on Earth to be the products of biology.

All extraterrestrial particles are heated during their passage through the Earth's atmosphere. The mineral assemblages that form during entry heating can be used to constrain the maximum temperature attained which, in turn, places limits on their entry velocity Entry velocity can be used to discriminate typical cometary IDPs from asteroidal particles.

A common feature of heated IDPs is the presence of magnetite (Mt) rims on the particle surface. These rims range from thin, discontinuous Mt layers on lobes or on small constituent grains within lightly heated IDPs, to thick, continuous, polycrystalline rims that completely surround many strongly heated particles. Petrographic evidence indicates that Mt rims form directly from individual phases in IDPs via oxidation of Fe from the host phases. Our data indicate that the temperature of magnetite formation can range from a minimum of ~600°C (by decarbonation of Fe-bearing carbonates and the breakdown of phyllosilicates) to T > 850°C (decomposition of laihunite). In extreme cases, μm-sized Mt plates armor the surface of partly melted chondritic IDPs. Magnetite rims are more well-developed on hydrated IDPs than on anhydrous particles. The development of magnetite rims correlates with other independent indicators of heating including loss of volatile trace elements and sulfur depletions.

Over 100 individual and cluster interplanetary dust particles (IDPs) have been analyzed for bulk abundances of 15 elements (C, O, Na, Mg, Al, Si, P, S, K, Ca, Ti, Cr, Mn, Fe, Ni). In general, IDPs have chondritic major element abundances, within a factor of 2 of the CI chondrites, and have carbon contents which average ~2-3 times higher than that of the most primitive, carbon-rich, carbonaceous meteorites (CI). The C-rich material is largely amorphous and is distributed throughout the particle as a matrix surrounding individual grains. The carbonaceous material has either smooth or vesicular texture; the latter texture suggests that volatiles could have been lost by particle heating which occurs during entry through the Earth's atmosphere.