Scintillation efficiency of liquid xenon for nuclear recoils with the energy down to 5 keV

The scintillation efficiency of liquid xenon for nuclear recoils has been measured to be nearly constant in the recoil energy range from 140 keV down to 5 keV. The average ratio of the efficiency for recoils to that for gamma-rays is found to be 0.19+-0.02.Comment: 13 pages, 5 figure

The delivery of personalised, precision medicines via synthetic proteins

Introduction: The design of advanced drug delivery systems based on synthetic and su-pramolecular chemistry has been very successful. Liposomal doxorubicin (Caelyx®), and liposomal daunorubicin (DaunoXome®), estradiol topical emulsion (EstrasorbTM) as well as soluble or erodible polymer systems such as pegaspargase (Oncaspar®) or goserelin acetate (Zoladex®) represent considerable achievements. The Problem: As deliverables have evolved from low molecular weight drugs to biologics (currently representing approximately 30% of the market), so too have the demands made of advanced drug delivery technology. In parallel, the field of membrane trafficking (and endocytosis) has also matured. The trafficking of specific receptors i.e. material to be recycled or destroyed, as well as the trafficking of protein toxins has been well characterized. This, in conjunction with an ability to engineer synthetic, recombinant proteins provides several possibilities. The Solution: The first is using recombinant proteins as drugs i.e. denileukin diftitox (Ontak®) or agalsidase beta (Fabrazyme®). The second is the opportunity to use protein toxin architecture to reach targets that are not normally accessible. This may be achieved by grafting regulatory domains from multiple species to form synthetic proteins, engineered to do multiple jobs. Examples include access to the nucleocytosolic compartment. Herein the use of synthetic proteins for drug delivery has been reviewed

The role of skeletal micro-architecture in diagenesis and dating of Acropora palmata

Past variations in global sea-level reflect continental ice volume, a crucial factor for understanding the Earth's climate system. The Caribbean coral Acropora palmata typically forms dense stands in very shallow water and therefore fossil samples mark past sea-level. Uranium-series methods are commonly used to establish a chronology for fossil coral reefs, but are compromised by post mortem diagenetic changes to coral skeleton. Current screening approaches are unable to identify all altered samples, whilst models that attempt to correct for 'open-system' behaviour are not applicable across all diagenetic scenarios. In order to better understand how U-series geochemistry varies spatially with respect to diagenetic textures, we examine these aspects in relation to skeletal micro-structure and intra-crystalline amino acids, comparing an unaltered modern coral with a fossil A. palmata colony containing zones of diagenetic alteration (secondary overgrowth of aragonite, calcite cement and dissolution features). We demonstrate that the process of skeletogenesis in A. palmata causes heterogeneity in porosity, which can account for the observed spatial distribution of diagenetic features; this in turn explains the spatially-systematic trends in U-series geochemistry and consequently, U-series age. We propose a scenario that emphasises the importance of through-flow of meteoric waters, invoking both U-loss and absorption of mobilised U and Th daughter isotopes. We recommend selective sampling of low porosity A. palmata skeleton to obtain the most reliable U-series ages. We demonstrate that intra-crystalline amino acid racemisation (AAR) can be applied as a relative dating tool in Pleistocene A. palmata samples that have suffered heavy dissolution and are therefore unsuitable for U-series analyses. Based on relatively high intra-crystalline concentrations and appropriate racemisation rates, glutamic acid and valine are most suited to dating mid-late Pleistocene A. palmata. Significantly, the best-preserved material in the fossil specimen yields a U-series age of 165 ± 8 ka, recording a paleo sea-level of -35 ± 7 msl during the MIS 6.5 interstadial on Barbados

US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017

The impact of molecular data in fungal systematics

Molecular data has been used in fungal systematics since the 1970s, and its rate of incorporation has increased significantly in recent years. In phylogeny molecular data has already been used to clarify major evolutionary lines, and has aided in the delineation of higher taxonomic groups including the kingdom Fungi, and the main phyla within it. Molecular data has been used at all taxonomic levels and has allowed for a greater phylogenetic signal to be represented within systematic groups. At the higher levels this has led to the re-evaluation of some orders and families, and at lower taxonomic levels it has helped in the identification of species, particular populations and possibly individuals. There are however some limitations to the widespread use of molecular data. Some of these relate to the comparability and utility of methods between different fungal groups, some relate to the wide diversity of life cycles adopted by fungi, and others are due to the paucity of comparable definitive evolutionary markers. A significant limitation to the wider application of molecular data is the restricted range of data currently available, and the relation of this to the as yet unquantified numbers of undescribed species. Despite these limitations molecular data has had a very significant effect on our understanding of fungal systematics, and many further systematic aspects are likely to be elucidated in the future

A multilevel modular converter for a large, lightweight wind turbine generator

In an onshore horizontal axis wind turbine, generator and converter are usually in the nacelle on the top of the tower, while the grid step-up transformer is placed at the bottom. Electric power is transmitted down through flexible cables of high current rating which are expensive and can suffer from large I2 R loss. An offshore wind turbine usually has to include the step-up transformer in the nacelle. This adds significantly to the mechanical loading of the tower even new designs aim to reduce the transformer size and weight. In either case, a transformer-less, high voltage, high reliability generating unit for nacelle installation would be an attractive technology for large wind turbines. This study presents a power electronic solution based on a permanent magnet generator design. A multilevel cascaded voltage source converter is developed to synthesize a high sinusoidal output voltage. The dc link voltages of inverter modules are balanced by rectifiers fed from isolated generator coils while the inverter switching strategy equalizes the power sharing between the modules. The switching strategy also reduces the low order harmonics to constrain the sizing of the dc link capacitors. The modulating effect between the ac and dc sides of the inverter is taken into account. This paper describes the generator-converter arrangement, analyzes the inverter switching effects and derives the switching strategy which is verified by simulation and laboratory experiment