Maclisp extensions

A common subset of selected facilities available in Maclisp and its derivatives (PDP-10 and Multics Maclisp, Lisp Machine Lisp (Zetalisp), and NIL) is decribed. The object is to add in writing code which can run compatibly in more than one of these environments

Advanced InSAR atmospheric correction: MERIS/MODIS combination and stacked water vapour models

A major source of error for repeat-pass Interferometric Synthetic Aperture Radar (InSAR) is the phase delay in radio signal propagation through the atmosphere (especially the part due to tropospheric water vapour). Based on experience with the Global Positioning System (GPS)/Moderate Resolution Imaging Spectroradiometer (MODIS) integrated model and the Medium Resolution Imaging Spectrometer (MERIS) correction model, two new advanced InSAR water vapour correction models are demonstrated using both MERIS and MODIS data: (1) the MERIS/MODIS combination correction model (MMCC); and (2) the MERIS/MODIS stacked correction model (MMSC). The applications of both the MMCC and MMSC models to ENVISAT Advanced Synthetic Aperture Radar (ASAR) data over the Southern California Integrated GPS Network (SCIGN) region showed a significant reduction in water vapour effects on ASAR interferograms, with the root mean square (RMS) differences between GPS- and InSAR-derived range changes in the line-of-sight (LOS) direction decreasing from ,10mm before correction to ,5mm after correction, which is similar to the GPS/MODIS integrated and MERIS correction models. It is expected that these two advanced water vapour correction models can expand the application of MERIS and MODIS data for InSAR atmospheric correction. A simple but effective approach has been developed to destripe Terra MODIS images contaminated by radiometric calibration errors. Another two limiting factors on the MMCC and MMSC models have also been investigated in this paper: (1) the impact of the time difference between MODIS and SAR data; and (2) the frequency of cloud-free conditions at the global scale

Membranes in rod solutions: a system with spontaneously broken symmetry

We consider a dilute solution of infinitely rigid rods near a curved, perfectly repulsive surface and study the contribution of the rod depletion layer to the bending elastic constants of membranes. We find that a spontaneous curvature state can be induced by exposure of BOTH sides of the membrane to a rod solution. A similar result applies for rigid disks with a diameter equal to the rod's length. We also study the confinement of rods in spherical and cylindrical repulsive shells. This helps elucidate a recent discussion on curvature effects in confined quantum mechanical and polymer systems.Comment: 10 pages, 2 figures, 1 table; submitted to PR

Digital identity of researchers and their personal learning network

Paper produzido no âmbito da Tese de Doutoramento em Educação, especialidade de Educação a Distância e eLearning (EDeL), Universidade Aberta.In a networked society, everyday experience is shared in networks at a personal, professional and academic level. Thus, there is a need to have digital literacy skills to obtain and produce contents in a collaborative way, sharing the knowledge acquired in the personal learning network. This paper is a reflection of literature revision in the PhD project of Online Distance Education and e-learning, concerning themes such as digital identity and personal learning networks. In this way we aim to make a literature analysis about the necessity of digital literacy so that we may obtain competencies for a personal learning network.info:eu-repo/semantics/publishedVersio

Direct observation of spin-polarised bulk bands in an inversion-symmetric semiconductor

Methods to generate spin-polarised electronic states in non-magnetic solids are strongly desired to enable all-electrical manipulation of electron spins for new quantum devices. This is generally accepted to require breaking global structural inversion symmetry. In contrast, here we present direct evidence from spin- and angle-resolved photoemission spectroscopy for a strong spin polarisation of bulk states in the centrosymmetric transition-metal dichalcogenide WSe$_2$. We show how this arises due to a lack of inversion symmetry in constituent structural units of the bulk crystal where the electronic states are localised, leading to enormous spin splittings up to $\sim\!0.5$ eV, with a spin texture that is strongly modulated in both real and momentum space. As well as providing the first experimental evidence for a recently-predicted `hidden' spin polarisation in inversion-symmetric materials, our study sheds new light on a putative spin-valley coupling in transition-metal dichalcogenides, of key importance for using these compounds in proposed valleytronic devices.Comment: 6 pages, 4 figure

Spin-valley locking in the normal state of a transition-metal dichalcogenide superconductor

We gratefully acknowledge support from the Engineering and Physical Sciences Research Council, UK (work at St Andrews under Grant No. EP/I031014/1 and work at Warwick under Grant No. EP/M028771/1) and the International Max Planck partnership. PDCK acknowledges support from the Royal Society through a University Research Fellowship. MSB was supported by the Grant-in-Aid for Scientific Research (S) (No. 24224009) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. LB, JR, and VS acknowledge studentship funding from EPSRC through grant nos. EP/G03673X/1, EP/L505079/1, and EP/L015110/1, respectively. The experiments at MAX IV Laboratory were made possible through funding from the Swedish Research Council and the Knut and Alice Wallenberg Foundation.Metallic transition-metal dichalcogenides (TMDCs) are benchmark systems for studying and controlling intertwined electronic orders in solids, with superconductivity developing from a charge density-wave state. The interplay between such phases is thought to play a critical role in the unconventional superconductivity of cuprates, Fe-based, and heavy-fermion systems, yet even for the more moderately-correlated TMDCs, their nature andorigins have proved controversial. Here, we study a prototypical example, 2H-NbSe2, by spin-and angle-resolved photoemission and first-principles theory. We find that the normal state,from which its hallmark collective phases emerge, is characterised by quasiparticles whose spin is locked to their valley pseudospin. This results from a combination of strong spin-orbit interactions and local inversion symmetry breaking, while interlayer coupling further drives a rich three-dimensional momentum dependence of the underlying Fermi surface spintexture. These findings necessitate a re-investigation of the nature of charge order and superconducting pairing in NbSe2 and related TMDCs.Publisher PDFPeer reviewe

Sheep -Wool I AN INTEGRATED GENOMICS APPROACH TO IMPROVING WOOL PRODUCTIVITY AND QUALITY

SUMMARY This paper summarises the approach taken in a national research program designed to "identify and utilise genes of importance in the sheep industries". The sheepgenomics program as it was known, comprised meat, wool and parasite subprograms with an underpinning core technology subprogram. The wool subprogram used a combination of gene association and functional biology studies to identify genes and gene networks amenable to manipulation or selection to improve wool production and quality. Significant progress was made in identifying genes involved in wool follicle initiation, hair cycle regulation, recessive black pigmentation and fleece rot. Manipulation of key windows of foetal development resulted in lifetime positive changes in wool production, an important proof of concept in functional, developmental genomics. INTRODUCTION The Australian wool industry operates in a highly-competitive, global, textile fibre market in which it currently captures a small and diminishing share of the consumer's expenditure on apparel clothing. To remain competitive in this market, the industry must address a number of pressing issues which are limiting productivity, profitability and consumer acceptance of the products. These include mulesing, dark fibre contamination, fleece rot, flystrike, anthelminthic resistance, relatively coarse fibres, weak fibres, prickle in garments, poor easy-care attributes and high price relative to competitors. At the time of inception of the sheepGENOMICS program (2004), molecular genetics applied to animal breeding was in its infancy, with great expectations attached to the discovery of quantitative trait loci (QTL) for difficult-to-measure traits. Since then, high throughput single nucleotide polymorphism (SNP) genotyping has paved the way for whole genome selection and more targeted SNP marker identification. Developments in bioinformatics, and in particular, networked pathway analyses, now allow more functionally-relevant interpretation of gene expression studies. The wool subprogram of the sheepGENOMICS initiative developed an integrated, functional genomics approach to dissect the molecular and cellular events involved in the critical periods of development of the follicle population in the skin of developing sheep foetuses. A suite of techniques for gene detection, gene expression, gene localisation, gene transfection, in vitro cell functional assays, gene network analysis and biochemical manipulations were targeted at key windows of skin development and at the longstanding problems of fleece rot and recessive black fibre pigmentation. These techniques and a summary of progress to date are the subject of this paper

Introducing systems approaches

Systems Approaches to Managing Change brings together five systems approaches to managing complex issues, each having a proven track record of over 25 years. The five approaches are: System Dynamics (SD) developed originally in the late 1950s by Jay Forrester Viable Systems Model (VSM) developed originally in the late 1960s by Stafford Beer Strategic Options Development and Analysis (SODA: with cognitive mapping) developed originally in the 1970s by Colin Eden Soft Systems Methodology (SSM) developed originally in the 1970s by Peter Checkland Critical Systems Heuristics (CSH) developed originally in the late 1970s by Werner Ulrich