A dense 0.1-solar-mass star in a 51-minute-orbital-period eclipsing binary.

Of more than a thousand known cataclysmic variables (CVs), where a white dwarf is accreting from a hydrogen-rich star, only a dozen have orbital periods below 75 minutes. One way to achieve these short periods requires the donor star to have undergone substantial nuclear evolution before interacting with the white dwarf, and it is expected that these objects will transition to helium accretion. These transitional CVs have been proposed as progenitors of helium CVs.

Degradation Performance of Open-Cell Biomaterials from Phosphated Carbonyl Iron Powder with PEG Coating.

Advances in biomedicine and development of modern technologies in the last century have fostered the improvement in human longevity and well-being. This progress simultaneously initiated the need for novel biomaterials. Recently, degradable metallic biomaterials have attracted serious attention in scientific and clinical research owing to their utilization in some specific applications.

General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system.

General relativity predicts that short-orbital-period binaries emit considerable amounts of gravitational radiation. The upcoming Laser Interferometer Space Antenna (LISA) is expected to detect tens of thousands of such systems but few have been identified, of which only one is eclipsing-the double-white-dwarf binary SDSS J065133.338+284423.

The skull roof tracks the brain during the evolution and development of reptiles including birds.

Major transformations in brain size and proportions, such as the enlargement of the brain during the evolution of birds, are accompanied by profound modifications to the skull roof. However, the hypothesis of concerted evolution of shape between brain and skull roof over major phylogenetic transitions, and in particular of an ontogenetic relationship between specific regions of the brain and the skull roof, has never been formally tested. We performed 3D morphometric analyses to examine the deep history of brain and skull-roof morphology in Reptilia, focusing on changes during the well-documented transition from early reptiles through archosauromorphs, including nonavian dinosaurs, to birds.

Oxygen isotopes suggest elevated thermometabolism within multiple Permo-Triassic therapsid clades.

The only true living endothermic vertebrates are birds and mammals, which produce and regulate their internal temperature quite independently from their surroundings. For mammal ancestors, anatomical clues suggest that endothermy originated during the Permian or Triassic. Here we investigate the origin of mammalian thermoregulation by analysing apatite stable oxygen isotope compositions (δO) of some of their Permo-Triassic therapsid relatives.

An early geikiid dicynodont from the Assemblage Zone (late Permian) of South Africa.

Based on specimens previously identified as , a new taxon of dicynodont ( gen. et sp. nov.

Fossorial Origin of the Turtle Shell.

The turtle shell is a complex structure that currently serves a largely protective function in this iconically slow-moving group [1]. Developmental [2, 3] and fossil [4-7] data indicate that one of the first steps toward the shelled body plan was broadening of the ribs (approximately 50 my before the completed shell [5]). Broadened ribs alone provide little protection [8] and confer significant locomotory [9, 10] and respiratory [9, 11] costs.

New Permian fauna from tropical Gondwana.

Terrestrial vertebrates are first known to colonize high-latitude regions during the middle Permian (Guadalupian) about 270 million years ago, following the Pennsylvanian Gondwanan continental glaciation. However, despite over 150 years of study in these areas, the biogeographic origins of these rich communities of land-dwelling vertebrates remain obscure. Here we report on a new early Permian continental tetrapod fauna from South America in tropical Western Gondwana that sheds new light on patterns of tetrapod distribution.

A temnospondyl trackway from the early Mesozoic of western Gondwana and its implications for basal tetrapod locomotion.

Background: Temnospondyls are one of the earliest radiations of limbed vertebrates. Skeletal remains of more than 190 genera have been identified from late Paleozoic and early Mesozoic rocks. Paleozoic temnospondyls comprise mainly small to medium sized forms of diverse habits ranging from fully aquatic to fully terrestrial.

Provincialization of terrestrial faunas following the end-Permian mass extinction.

In addition to their devastating effects on global biodiversity, mass extinctions have had a long-term influence on the history of life by eliminating dominant lineages that suppressed ecological change. Here, we test whether the end-Permian mass extinction (252.3 Ma) affected the distribution of tetrapod faunas within the southern hemisphere and apply quantitative methods to analyze four components of biogeographic structure: connectedness, clustering, range size, and endemism.

Liquid chromatography-flame ionisation detection using a nebuliser/spray chamber interface. Part 2. Comparison of functional group responses.

The application of a LC-nebuliser/spray chamber interface-flame ionisation detection has been demonstrated for the superheated water liquid chromatography of a wide range of aliphatic and aromatic analytes. The linearity and sensitivity of the response of volatile and involatile analytes have been compared. The response of the detector toward different analytes is similar to that in GC-FID and for volatile analytes was comparable to UV detection.

Liquid chromatography-flame ionisation detection using a nebuliser/spray chamber interface. Part 1. Design and testing.

A nebuliser and spray chamber have been used to link a flow injection analyser to a flame ionisation detector, with the potential for the combination to be used as a universal detector for liquid chromatography. The hydrogen and air flows were adjusted to achieve a stable system. The detector responded to both volatile and involatile analytes and to compounds with and without chromophores, including alkanes, alkanols, aromatic amides and acids, phenols, amino-acids and carbohydrates and gave a linear response for many analytes.

The last "pelycosaur": a varanopid synapsid from the Pristerognathus Assemblage Zone, Middle Permian of South Africa.

We report on a partial varanopid skull and mandible from the Pristerognathus Assemblage Zone of the Beaufort Group, in the South African Karoo Basin, which is probably latest Middle Permian (Capitanian) in age. This mycterosaurine is not only the youngest known varanopid from the Southern Hemisphere, but it is also the youngest known "pelycosaur" (i.e.

Impact of a tailored patient preference intervention in adherence to 5-aminosalicylic acid medication in ulcerative colitis: results from an exploratory randomized controlled trial.

Background: Up to 40% of patients with ulcerative colitis (UC) fail to comply with 5-aminosalicylic acid (5-ASA) therapy. This study aimed to evaluate multifaceted adherence-enhancing interventions for oral 5-ASA therapy in UC and consider changes in health beliefs and satisfaction with information.

Methods: Adults attending a UK gastroenterology outpatient clinic were recruited to an exploratory randomized controlled trial.

An alternative method for analysis of food taints using stir bar sorptive extraction.

The determination of taints in food products currently can involve the use of several sample extraction techniques, including direct headspace (DHS), steam distillation extraction (SDE) and more recently solid phase microextraction (SPME). Each of these techniques has disadvantages, such as the use of large volumes of solvents (SDE), or limitations in sensitivity (DHS), or have only been applied to date for determination of individual or specific groups of tainting compounds (SPME). The use of stir bar sorptive extraction (SBSE) has been evaluated as a quantitative screening method for unknown tainting compounds in foods.

Subcritical water extraction of trace metals from petroleum source rock.

The extraction of trace metals from petroleum source rock by superheated water was investigated and the conditions for maximum yield were determined. The results showed that no significant extraction was attained at 100 degrees C but the extraction was enhanced at higher temperatures. The optimum temperature for superheated water extraction of the metals from petroleum source rocks was 250 degrees C.

Superheated water extraction of essential oils from Cinnamomum zeylanicum (L.).

Introduction: Superheated water extraction (SHWE) potentially provides an environmentally friendly and clean extraction technique which uses a minimum or no organic solvent. The scope and limitations of the technique have still to be fully explored.

Objective: To investigate the application of SHWE to cinnamon (Cinnamomum zeylanicum L.

Ecologically distinct dinosaurian sister group shows early diversification of Ornithodira.

The early evolutionary history of Ornithodira (avian-line archosaurs) has hitherto been documented by incomplete (Lagerpeton) or unusually specialized forms (pterosaurs and Silesaurus). Recently, a variety of Silesaurus-like taxa have been reported from the Triassic period of both Gondwana and Laurasia, but their relationships to each other and to dinosaurs remain a subject of debate. Here we report on a new avian-line archosaur from the early Middle Triassic (Anisian) of Tanzania.

The use of stir bar sorptive extraction--a potential alternative method for the determination of furan, evaluated using two example food matrices.

A comparison is made between static headspace analysis and stir bar sorptive extraction (SBSE) for the quantitative determination of furan. The SBSE technique was optimised and evaluated using two example food matrices (coffee and jarred baby food). The use of the SBSE technique in most cases, gave comparable results to the static headspace method, using the method of standard additions with d4-labelled furan as an internal standard.

Dynamic locomotor capabilities revealed by early dinosaur trackmakers from southern Africa.

Background: A new investigation of the sedimentology and ichnology of the Early Jurassic Moyeni tracksite in Lesotho, southern Africa has yielded new insights into the behavior and locomotor dynamics of early dinosaurs.

Methodology/principal Findings: The tracksite is an ancient point bar preserving a heterogeneous substrate of varied consistency and inclination that includes a ripple-marked riverbed, a bar slope, and a stable algal-matted bar top surface. Several basal ornithischian dinosaurs and a single theropod dinosaur crossed its surface within days or perhaps weeks of one another, but responded to substrate heterogeneity differently.

High-temperature liquid chromatography of steroids on a bonded hybrid column.

A hybrid stationary phase, XTerra MS C18, has been evaluated for the high-temperature reversed-phase liquid chromatography of selected hydrophobic steroids. The effects on the retention and efficiency at temperatures up to 130 degrees C and eluent compositions from methanol-water mixtures to superheated water were studied. The thermodynamic data of the separations were determined.

Superheated water chromatography on phenyl bonded hybrid stationary phases.

Phenyl bonded XTerra and XBridge organic/inorganic hybrid stationary phases have been used to separate test solutes and phenol homologues with a pure water mobile phase over a temperature range from 40 to 200 degrees C. The van't Hoff relationships between retention factors and reciprocal temperature were non-linear and could either be interpreted as a systematic change in the properties of the XTerra phenyl column or a marked change in the phase material for the XBridge phenyl column. This was reflected in the methylene selectivity which also showed a change for the XBridge column.

Use of in-tube sorptive extraction techniques for determination of benzene, toluene, ethylbenzene and xylenes in soft drinks.

A comparison is made between static headspace analysis and headspace solid-phase dynamic extraction (HS-SPDE) for the quantitative determination of trace level BTEX solvents (benzene, toluene, ethylbenzene and o-, m-, and p-xylene) in soft drinks. Two non-polar extraction phases were investigated for SPDE using an automated sampler with a gas-tight syringe equipped with a special needle coated on the inside with the extraction phase. Following adsorption onto the phase, the analytes were thermally desorbed directly into a GC-MS.

Superheated water chromatography--a green technology for the future.

Reversed phase liquid chromatography using superheated water as the mobile phase, at temperatures between 100 and 250 degrees C, offers a number of advantages for the analyst. It is an environmentally clean solvent, reducing solvent usage and disposal costs. It has advantages in detection, allowing UV spectra to be monitored down to short wavelengths, as well as a compatibility with universal flame ionisation detection and mass spectroscopy.