Environmental distribution of Bathonian (Middle Jurassic) neoselachians in southern England

Within the Bathonian (Middle Jurassic) a wide range of depositional environments were present across Britain. Within this dominantly carbonate shelf setting, there is a general palaeoenvironmental transition from open marine shelf in the south of England, to marine and non-marine lagoons in south-central England. Isolated teeth of neoselachians are frequent at several localities within a range of marine and lagoonal facies. Extensive bulk sampling has allowed teeth from over 20 neoselachian taxa to be recovered from several distinct facies. The distributions of many species suggest that they were strongly environmentally controlled, with few taxa being commonly present within both open marine and lagoonal settings. Some taxonomic groups appear to have been restricted to specific environments, with hexanchids and palaeospinacids only being recorded within open marine facies. Within other groups, environmental segregation is at generic and specific level, with different species of Protospinax, orectolobids, batoids and scyliorhinids being recorded within different facies. The differential distribution of neoselachians within the Bathonian demonstrates that the initial phase of neoselachian radiation during the late Early and Middle Jurassic was accompanied by diversification into a wide range of ecological niches. This greatly increases our understanding of the mechanisms and timing of neoselachian radiation and Jurassic fish palaeoecolog

Near-IR Spectropolarimetry of NGC 1088

Original paper can be found at: http://www.astrosociety.org/pubs/cs/035-069.html--Copyright Astronomical Society of the PacificThe current unified model of Seyfert galaxies, as proposed by Antonucci and Miller (1985), has most, if not all, Seyfert 2 galaxies hosting a Seyfert 1 type nucleus in their cores. The broad lines from the type 1 nucleus can be scattered and be seen in the polarized flux spectrum, provided the geometry is correct. Whether the mechanism is electron or dust scattering has been a question of some debate. Since dust would normally have a low scattering efficiency in the infrared, near-IR spectropolarimetry should help in determing the nature of the scatterers. To this end we present the first near-IR spectropolarimetry of NGC 1068 a "Seyfert 2" galaxy in which polarized broad lines have been observed at optical wavelengths

Superior sperm competitors sire higher-quality young

The evolution of polyandry remains controversial. This is because, unlike males, in many cases multiple mating by females does not increase fecundity and inevitably involves some costs. As a result, a large number of indirect benefit models have been proposed to explain polyandry. One of these, the good sperm hypothesis, posits that high-quality males are better sperm competitors and sire higher-quality offspring. Hence, by mating multiply, females produce offspring of superior quality. Despite being potentially widely applicable across species, this idea has received little attention. In a laboratory experiment with yellow dung flies ( Scathophaga stercoraria ) we found that males that were more successful in sperm competition also had offspring that developed faster. There was no relationship between paternal success in sperm competition and the ability of offspring to survive post-emergence starvation. Since faster development times are likely to be advantageous in this species, our data provide some support for polyandry evolving as a means of producing higher-quality offspring via sperm competition

A note on brain actuated spelling with the Berlin brain-computer interface

Brain-Computer Interfaces (BCIs) are systems capable of decoding neural activity in real time, thereby allowing a computer application to be directly controlled by the brain. Since the characteristics of such direct brain-tocomputer interaction are limited in several aspects, one major challenge in BCI research is intelligent front-end design. Here we present the mental text entry application ‘Hex-o-Spell’ which incorporates principles of Human-Computer Interaction research into BCI feedback design. The system utilises the high visual display bandwidth to help compensate for the extremely limited control bandwidth which operates with only two mental states, where the timing of the state changes encodes most of the information. The display is visually appealing, and control is robust. The effectiveness and robustness of the interface was demonstrated at the CeBIT 2006 (world’s largest IT fair) where two subjects operated the mental text entry system at a speed of up to 7.6 char/min

Highly tunable thiosulfonates as a novel class of cysteine protease inhibitors with anti-parasitic activity against Schistosoma mansoni

The development of a new class of cysteine protease inhibitors utilising the thiosulfonate moiety as an SH specific electrophile is described. This moiety has been introduced into suitable amino acid derived building blocks, which were incorporated into peptidic sequences leading to very potent i.e. sub micromolar inhibitors of the cysteine protease papain in the same range as the vinyl sulfone based inhibitor K11777. Therefore, their inhibitory effect on Schistosoma mansoni, a human blood parasite, that expresses several cysteine proteases, was evaluated. The homophenylalanine side chain containing compounds 27 - 30 and especially 36 showed promising activities compared with K11777 and warrant further investigations of these peptidic thiosulfonate inhibitors as new potential anti-parasitic compounds

Neoselachian sharks and rays from the British Bathonian (Middle Jurassic)

Extensive sampling of Bathonian sediments from localities across southern and central England has produced over 8000 neoselachian teeth. These comprise diverse faunas, with over 25 species being represented in total, most of them previously undescribed. Seventeen new species and seven new genera are named: Palaeoscyllium tenuidens sp. nov., Praeproscyllium oxoniensis gen. et sp. nov., Eypea leesi gen. et sp. nov., Proheterodontus sylvestris gen. et sp. nov., Paracestracion bellis sp. nov., Palaeobrachaelurus mussetti sp. nov., Heterophorcynus microdon gen. et sp. nov., Dorsetoscyllium terraefullonicum gen. et sp. nov., Ornatoscyllium freemani gen. et sp. nov., Pseudonotidanus semirugosus gen. et sp. nov., Synechodus duffini sp. nov., Protospinax magnus sp. nov., P. bilobatus sp. nov., P. carvalhoi sp. nov., Belemnobatis kermacki sp. nov., B. stahli sp. nov. and Spathobatis delsatei sp. nov. In addition, a new family, the Pseudonotidanidae fam. nov., is defined and the status of Paranotidanus Ward and Thies, 1987, Hybodus levis Woodward, 1889 and Breviacanthus brevis (Phillips, 1871) are discussed. These taxa show strong facies specificity, with different species being restricted to different palaeoenvironments

New Approach to GUTs

We introduce a new string-inspired approach to the subject of grand unification which allows the GUT scale to be small, \lesssim 200 TeV, so that it is within the reach of {\em conceivable} laboratory accelerated colliding beam devices. The key ingredient is a novel use of the heterotic string symmetry group physics ideas to render baryon number violating effects small enough to have escaped detection to date. This part of the approach involves new unknown parameters to be tested experimentally. A possible hint at the existence of these new parameters may already exist in the EW precision data comparisons with the SM expectations.Comment: 8 pages; improved text and references, note added; extended text, 1 figure added; extended text for publication in Eur. Phys. Journal

The Hopf algebra of Feynman graphs in QED

We report on the Hopf algebraic description of renormalization theory of quantum electrodynamics. The Ward-Takahashi identities are implemented as linear relations on the (commutative) Hopf algebra of Feynman graphs of QED. Compatibility of these relations with the Hopf algebra structure is the mathematical formulation of the physical fact that WT-identities are compatible with renormalization. As a result, the counterterms and the renormalized Feynman amplitudes automatically satisfy the WT-identities, which leads in particular to the well-known identity $Z_1=Z_2$.Comment: 13 pages. Latex, uses feynmp. Minor corrections; to appear in LM