We conducted a series of experiments that revealed the formation of mm-scale penitente structures in ice illuminated by broadband light under moderate vacuum conditions between 50 and 2000 Pa. The experimental apparatus consists of a 0.3 m diameter cylindrical vacuum chamber with a cooling jacket surrounding the outer radius and bottom surface. Light shines in through an optical window at the top to illuminate most of the ice surface. We observe penitente-like structures at temperatures between −15$^\circ$C and $-2^\circ$C and pressures close to the equilibrium vapor pressure at the ice surface temperature. The formation of these structures is very sensitive to slight changes in background pressure, and the structures tend to vanish with significant deviations away from the equilibrium curve, resulting in a smooth sublimated crater formation instead of penitentes. Application of the physical model by Claudin and others (2015, doi: 10.1103/PhysRevE.92.033015) at experimental conditions generally agrees with observations for penitente spacing.

Despite the recognition that bone histology provides much information about the life history and biology of extinct animals, osteohistology of extinct marsupials is sorely lacking. We studied the bone histology of the ca. 15-million-year-old Nimbadon lavarackorum from Australia to obtain insight into its biology. The histology of thin sections of five femora and five tibiae of juveniles, subadult, and adult Nimbadon lavarackorum was studied. Growth marks in the bones suggest that N. lavarackorum took at least 7–8 years (and likely longer) to reach skeletal maturity. The predominant bone tissue during early ontogeny is parallel-fibered bone, whereas an even slower rate of bone formation is indicated by the presence of lamellar bone tissue in the periosteal parts of the compacta in older individuals. Deposition of bone was interrupted periodically by lines of arrested growth or annuli. This cyclical growth strategy indicates that growth in N. lavarackorum was affected by the prevailing environmental conditions and available resources, as well as seasonal physiological factors such as decreasing body temperatures and metabolic rates.

We estimate the ecosystem service value of water supplied by the San Bernardino National Forest in Southern California under climate change projections through the 21st century. We couple water flow projections from a dynamic vegetation model with an economic demand model for residential water originating from the San Bernardino National Forest. Application of the method demonstrates how estimates of consumer welfare changes due to variation in water supply from public lands in Southern California can inform policy and land management decisions. Results suggest variations in welfare changes over time due to alterations in the projected water supply surpluses, shifting demand limited by water supply shortages or surpluses, and price increases. Results are sensitive to future climate projections—in some cases large decreases in welfare due to supply shortages—and to assumptions about the demand model.

Philip Kitcher has proposed an account of mathematical truth which he hopes avoids platonistic commitment to abstract mathematical objects. His idea is that the truth-conditions of mathematical statements consist in certain general structural features of physical reality. He codifies these structural features by reference to various operations which are performable on objects: the world is structured in such a way that these operations are possible. Which operations are performable cannot be known a priori; rather, we hypothesize, conjecture, idealize, and eventually wind up with theories which are true of the world (taking into account our idealizations), just as we do in the sciences. Kitcher argues that mathematical and physical knowledge are continuous, in that they concern the same subject matter (the physical world) and are subject to the same epistemological and methodological constraints.

Plato himself would be pleased at the recent emergence of a certain highly Platonic variety of platonism concerning mathematics, viz., the structuralism of Michael Resnik and Stewart Shapiro. In fact, this species of platonism is so Platonic that it is susceptible to an objection closely related to one raised against Plato by Parmenides in the dialogue of that name. This is the Third Man Argument (TMA) against a view about the relation of Forms to particulars. My objection is not a TMA against structuralism; the position avoids that objection, but is vulnerable to a different one precisely at the point where it avoids the TMA. The way structuralism avoids the TMA has in fact been considered, as one of Plato’s options, by at least one commentator on the Parmenides, Colin Strang, who explicitly rejects it on logical grounds. In the course of the discussion, I shall clarify the reason that I believe led Strang to reject this option, and shall modify his own statement of that reason.

This study investigates the use of ‘simple’ glasses, comprising six components, to represent the structure of complex LAW glasses proposed for Immobilized Low Activity Wastes from the Hanford site in the USA. The 18 elements present in ILAW glasses LAW A44, ORP LB2, and LAW A23 were represented by Al2O3, B2O3, CaO, Na2O, SiO2, and ZrO2 according to their coordination chemistry and their roles as network formers and modifiers. The dissolution behavior of each ‘simple’ glass was compared to its corresponding candidate “complex” LAW glass through PCT-B tests. Significant differences were observed; the durability of complex glasses was concluded to be LAW A44 > ORP LB2 ≥ LAW A23 whereas in their simplified versions the order was LAW A44 > LAW A23 > ORP LB2. These results are discussed in relation to compositional differences and highlight the importance of minor glass components in controlling glass durability. The implications of these results for the use of simplified glass compositions are discussed.

Minimum Sample Richness (MSR) is defined as the smallest number of taxa that must be recorded in a sample to achieve a given level of inter-assemblage classification accuracy. MSR is calculated from known or estimated richness and taxonomic similarity. Here we test MSR for strengths and weaknesses by using 167 published mammalian local faunas from the Paleogene and early Neogene of the Quercy and Limagne area (Massif Central, southwestern France), and then apply MSR to 84 Oligo-Miocene faunas from Riversleigh, northwestern Queensland, Australia. In many cases, MSR is able to detect the assemblages in the data set that are potentially too incomplete to be used in a similarity-based comparative taxonomic analysis. The results show that the use of MSR significantly improves the quality of the clustering of fossil assemblages. We conclude that this method can screen sample assemblages that are not representative of their underlying original living communities. Ultimately, it can be used to identify which assemblages require further sampling before being included in a comparative analysis.

We describe Numbigilga ernielundeliusi new genus and species, a highly unusual marsupial represented by a partial right mandible with p2-m4 and a left upper molar from early Pliocene deposits at Bluff Downs, Queensland, northeastern Australia. Numbigilga n. gen. is characterized by a bunodont dentition with a number of striking specializations, and we refer it to Numbigilgidae new family. This taxon shares a range of dental apomorphies with various bunodont marsupial groups from the Late Cretaceous of North America and Paleogene of Gondwana. However, many of these features are most likely highly homoplastic within marsupials, reflecting convergent adaptations to a frugivorous-omnivorous diet. Other dental characters suggest possible affinities to the Australian order Peramelemorphia (bandicoots). Alternatively, Numbigilga may be a representative of an entirely new order of Australian marsupials. in the absence of more nearly complete specimens that might clarify its relationships, we refer Numbigilga to Marsupialia incertae sedis. We consider the distributions of a number of dental characters in bunodont marsupials and argue that no North American Late Cretaceous taxa can be convincingly referred to the order Polydolopimorphia. Thus, polydolopimorphians continue to be known only from the Cenozoic of Gondwana, with no fossil evidence that their initial divergences occurred in North America.

Alkaline earth aluminosilicate glasses (AeAS) with different MoO3 additions have been produced and assessed. MoO3 solubility increases with the equimolar substitution of smaller to larger alkaline earths and reaches 5.34 mol% in magnesium aluminosilicate glass (MAS). All visibly homogeneous glasses are X-ray amorphous, while the partially crystallised glasses exhibit some small X-ray diffraction peaks which are probably due to corresponding molybdates. The addition of MoO3 decreases glass transition and crystallisation temperatures and creates two broad Raman bands which are assigned to vibrations of MoO4 2‒ tetrahedra. The intensities of these bands increase along with MoO3 incorporation until the maximum solubility is reached. Electron microscopy shows that these separated particles are spherical, with sub-micron diameters and are randomly dispersed within glass. The separated phases are formed through liquid-liquid separation and thereafter crystallisation. Overall AeAS glasses look quite promising for molybdate immobilisation with MAS glasses being particularly attractive.

Vapour phase hydration studies of simulant Magnox waste glass have been undertaken at 200°C, over periods of 5 – 25 days. Electron microscopy studies reveal a thin uniform hydration layer (∼10 μm thick) on 5, 10 and 25 day specimens. The formation of isolated surface alteration products occurs between 5 and 10 days at 200°C. The formation of extensive surface alteration products, in the form of a magnesium sodium aluminosilicate, is observed only in the case of the 25 day specimen. The significance of these observations in the context of the composition of Magnox waste glass, is discussed.

The Théâtre du Grand-Guignol in Paris (1897–1962) achieved a legendary reputation as the ‘Theatre of Horror’, a venue displaying such explicit violence and blood-curdling terror that a resident doctor was employed to treat the numerous spectators who fainted each night. Indeed, the phrase ‘grand-guignolesque’ has entered the language to describe any display of heightened, remorseless horror. Such is the myth of the Grand-Guignol: the reality is subtler and far more complex.