Fossil proboscidean remains from Bolt's Farm and other Transvaal cave breccias

Proboscidean remains are very rare in the Transvaal cave breccias and the few specimens recovered are generally fragmentary but deserve description because of their potential value in correlation and dating. The best specimen is the back half of a left lower molar from Pit 7 of the University of California African Expedition's work at Bolt's Farm. It was regarded by Maglio as representing Elephas ekorensis but closer examination suggests that there are some more progressive characters and it most likely represents Elephas recki brumpti. The stump of a second molar from Bolt's farm also accords with this taxon. Makapansgat has furnished 14 fragmentary fossils, 6 of them tusk or root remains. Particularly interesting is the occurrence of a pair of cones from a molar of Anancus. The scrappy elephantid material from Makapansgat may be referred tentatively to an early stage of the Elephas recki lineage, as also a mandible fragment from Sterkfontein with the two anterior milk teeth. An anterior milk tooth from Swartkrans Member 3 exhibits broader and higher lamellae than in E. recki and most probably belongs to the more advanced E. iolensis to which most of the Vaal River elephants have been referred

Undescribed suid remains from Bolt's Farm and other Transvaal cave deposits

Although individual suid specimens from other sites have been described, only Makapansgat has been treated comprehensively, but much new material has come to light in the past three decades. The University of California African Expedition worked several sites of different ages at Bolt's Farm and the material recovered includes a virtually complete, slightly compressed, skull of Phacochoerus modestus (= P. antiquus Broom 1948) from Pit 3, associated with Antidorcas recki, and also several cranial and dental fragments from Pit 14 that belong to the typical Makapansgat Potamochoeroides shawi. Bolt's Farm was the source of a cranial specimen described by Broom as "Notochoerus meadowsi" (= Metridiochoerus andrewsi); other specimens referred to this taxon and described by Shaw as from "Sterkfontein Lime Works" more probably came from Bolt's Farm as well. Broom's cranium and a pair of mandibles have closer resemblances to Metridiochoerus jacksoni of East Africa. Swartkrans has yielded both described and undescribed material referred to Phacochoerus modestus and to Metridiochoerus. Discounting Shaw's material, only one small specimen has come from the Sterkfontein Type Site, a mandible fragment of a juvenile with an incompletely formed third molar in alveolus but it can be matched remarkably closely with a specimen from Makapansgat and there is very little doubt that it belongs to Potamochoeroides shawi. An undescribed third molar from the pink breccia at Makapansgat is comparable with early Notochoerus scotti from East Africa. The status of Notochoerus capensis is reconsidered.Wenner Gren Foundatio

Dinofelis barlowi (Mammalia, Carnivora, Felidae) cranial material from Bolt's Farm, collected by the University of California African expedition

The collections made by the University of California African Expedition in 1947-48 at Bolt's Farm, near Sterkfontein, included some fine cranial and postcranial material of Dinofelis barlowi, associated with baboon skeletons and crania suggestive of a natural trap situation. The Dinofelis crania are described and compared with other species of this genus, generally lending support to Hemmer's view of a lineage D. diastemata, D. harlowi, D. piveteaui. The age of the deposit is estimated to be in the vicinity of 2 Ma

Makapansgat suids and Metridiochoerus

Fossil suid material from Member 3 of the Makapansgat Formation was described as Potamochoeroides shawi but some authors have regarded it as an early stage of the Metridiochoerus andrewsi lineage. There is no complete cranium so a new reconstruction has been based on combining the data from a number of partial specimens. Comparison with Metridiochoerus andrewsi is difficult as there are reasons to suspect that the so-called ‘male’ and ‘female’ crania from Koobi Fora could be specifically distinct. An undescribed cranium from the Omo Shungura Formation is morphologically similar to the ‘male’ and is attributed to Metridiochoerus jacksoni. Comparison with the reconstructed Makapansgat suid indicates that the latter already shows an early stage in the distinctive architecture of the M. jacksoni cranium, as well as some resemblances in dental features. Accordingly it is suggested that the Makapansgat suid be designated as Metridiochoerus shawi. A few teeth from Member B11 of the Shungura Formation, with an age close to 2.95 Ma, are placed provisionally as M. cf. shawi; previously described molars referred to an early Notochoerus scotti are probably from a similar level. While this is suggestive, correlation is not firmly established.Wenner Gren Foundation for Anthropological Research and to the Canadian Council for Scientific and Industrial Researc

Obtaining Stiffness Exponents from Bond-diluted Lattice Spin Glasses

Recently, a method has been proposed to obtain accurate predictions for low-temperature properties of lattice spin glasses that is practical even above the upper critical dimension, $d_c=6$. This method is based on the observation that bond-dilution enables the numerical treatment of larger lattices, and that the subsequent combination of such data at various bond densities into a finite-size scaling Ansatz produces more robust scaling behavior. In the present study we test the potential of such a procedure, in particular, to obtain the stiffness exponent for the hierarchical Migdal-Kadanoff lattice. Critical exponents for this model are known with great accuracy and any simulations can be executed to very large lattice sizes at almost any bond density, effecting a insightful comparison that highlights the advantages -- as well as the weaknesses -- of this method. These insights are applied to the Edwards-Anderson model in $d=3$ with Gaussian bonds.Comment: corrected version, 10 pages, RevTex4, 12 ps-figures included; related papers available a http://www.physics.emory.edu/faculty/boettcher

Public Participation Organizations and Open Policy:A Constitutional Moment for British Democracy?

This article builds on work in Science and Technology Studies and cognate disciplines concerning the institutionalization of public engagement and participation practices. It describes and analyses ethnographic qualitative research into one “organization of participation,” the UK government–funded Sciencewise program. Sciencewise’s interactions with broader political developments are explored, including the emergence of “open policy” as a key policy object in the UK context. The article considers what the new imaginary of openness means for institutionalized forms of public participation in science policymaking, asking whether this is illustrative of a “constitutional moment” in relations between society and science policymaking

Interstellar medium disruption in the Centaurus A group

We present the results of a 21 cm neutral hydrogen (HI) line detection experiment in the direction of 18 low luminosity dwarf galaxies of the Centaurus A group, using the Australia Telescope National Facility 64m Parkes Radio Telescope and the Australia Telescope Compact Array. Five dwarfs have HI masses between M_HI=4x10^5 to M_HI=2.1x10^7 Msol and 0.04<M_HI/L_B<1.81 Msol L_{sol, B}^-1. The other 13 have upper-limits between M_HI<5x10^5 and M_HI<4x10^6 Msol (M_HI}/L_B<0.24 Msol L_{sol, B}^-1). Two of the mixed-morphology dwarfs remain undetected in HI, a situation that is in contrast to that of similar Local Group and Sculptor group objects where all contain significant amounts of neutral gas. There is a discontinuity in the HI properties of Centaurus A group low luminosity dwarfs that is unobserved amongst Sculptor group dwarfs. All objects fainter than M_B=-13 have either M_HI>10^7 Msol or M_HI<10^6 Msol. This gap may be explained by the ram pressure stripping mechanism at work in this dense environment where all galaxies with M_HI<10^7 Msol have been stripped of their gas. The required intergalactic medium density to achieve this is ~10^-3 cm^-3.Comment: 7 figures, 2 table

Correlated X-ray and Optical Variability in Mkn 509

We present results of a 3 year monitoring campaign of the Seyfert 1 galaxy Markarian 509, using X-ray data from the Rossi X-ray Timing Explorer (RXTE) and optical data taken by the SMARTS consortium. Both light curves show significant variations, and are strongly correlated with the optical flux leading the X-ray flux by 15 days. The X-ray power spectrum shows a steep high-frequency slope of -2.0, breaking to a slope of -1.0 at at timescale of 34 days. The lag from optical to X-ray emission is most likely caused by variations in the accretion disk propagating inward.Comment: 13 pages, 3 figures. Accepted for publication in the Astrophysical Journa

Highly conductive Sb-doped layers in strained Si

The ability to create stable, highly conductive ultrashallow doped regions is a key requirement for future silicon-based devices. It is shown that biaxial tensile strain reduces the sheet resistance of highly doped n-type layers created by Sb or As implantation. The improvement is stronger with Sb, leading to a reversal in the relative doping efficiency of these n-type impurities. For Sb, the primary effect is a strong enhancement of activation as a function of tensile strain. At low processing temperatures, 0.7% strain more than doubles Sb activation, while enabling the formation of stable, ~10-nm-deep junctions. This makes Sb an interesting alternative to As for ultrashallow junctions in strain-engineered complementary metal-oxide-semiconductor device