101,636 research outputs found
Reduced dimensionality spin-orbit dynamics of CH3 + HCl reversible arrow CH4 Cl on ab initio surfaces
No full textA reduced dimensionality quantum scattering method is extended to the study of spin-orbit nonadiabatic transitions in the CH3 + HCl reversible arrow CH4 + Cl(P-2(J)) reaction. Three two-dimensional potential energy surfaces are developed by fitting a 29 parameter double-Morse function to CCSD(T)/IB//MP2/cc-pV(T+d)Z-dk ab initio data; interaction between surfaces is described by geometry-dependent spin-orbit coupling functions fit to MCSCF/cc-pV(T+d)Z-dk ab initio data. Spectator modes are treated adiabatically via inclusion of curvilinear projected frequencies. The total scattering wave function is expanded in a vibronic basis set and close-coupled equations are solved via R-matrix propagation. Ground state thermal rate constants for forward and reverse reactions agree well with experiment. Multi-surface reaction probabilities, integral cross sections, and initial-state selected branching ratios all highlight the importance of vibrational energy in mediating nonadiabatic transition. Electronically excited state dynamics are seen to play a small but significant role as consistent with experimental conclusions. (C) 2011 American Institute of Physics. [doi:10.1063/1.3592732]</p
Caesarean delivery through deliberate posterior hysterotomy in irreducible uterine torsion
No full textActa Biomed. 2010 Sep;81(2):141-3.
Caesarean delivery through deliberate posterior hysterotomy in irreducible uterine torsion: case report.
De Ioris A, Pezzuto C, Nardelli GB, Modena AB.
SourceDepartment of Gynaecology, Obstetrics and Neonatology, University of Parma, Parma, Italy. [email protected]
Abstract
Gravid uterus rotation is a normal finding in the third trimester of pregnancy. However, a rotation greater than 45 degrees around the longitudinal axis of the uterus--uterine torsion--is a rare pathological condition in the obstetrical practice. We reporte the case of 180 degrees torsion of a myomatous uterus at preterm in which the foetus, in breech presentation, was delivered through a deliberate posterior hysterotomy. An emergency caesarean section was arranged after prolonged foetal bradycardia. Uterine torsion treatment depends on when the torsion occurs during the pregnancy. However, laparotomy is imperative in all cases. When derotation of the uterus is not possible, a transverse incision in the lower posterior uterine segment, if feasible, is a safe choice
AB-PAS staining in each group after 3,6,12 weeks.
No full text(A-C) AB-PAS staining in the sharm group after 3,6,12 weeks (×100). (D-F) AB-PAS staining in the injury group after 3,6,12 weeks (×100). (G-I) AB-PAS staining in the therapeutic groupafter 3,6,12 weeks (×100). Black arrows:cartilage cells.</p
C-BN single-walled nanotubes from hybrid connection of BN/C nanoribbons: Prediction by ab initio density functional calculations
No full textWe demonstrated for the first time by ab initio density functional calculation and molecular dynamics simulation that C-0.5(BN)(0.5) armchair single-waited nanotubes (NT) are gapless semiconductors and can be spontaneously formed via the hybrid connection of graphene/BN Nanoribbons (GNR/BNNR) at room temperature. The direct synthesis of armchair C-0.5(BN)(0.5) via the hybrid connection of GNR/BNNR is predicted to be both thermodynamically and dynamically stable. Such novel armchair C-0.5(BN)(0.5) NTs possess enhanced conductance as that observed in GNRs. Additionally, the zigzag C-0.5(BN)(0.5) SWNTs are narrow band gap semiconductors, which may have potential application for light emission. In light of recent experimental progress and the enhanced degree of control in the synthesis of GNRs and BNNR, our results highlight an interesting avenue for synthesizing a novel specific type of C-0.5(BN)(0.5) nanotube (gapless or narrow direct gap semiconductor), with potentially important applications in BNC-based nanodevices
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Zebrafish microRNA-126 determines hematopoietic cell fate through c-Myb.
No full textPrecise regulatory mechanisms are required to appropriately modulate the cellular levels of transcription factors controlling cell fate decisions during blood cell development. In this study, we show that miR-126 is a novel physiological regulator of the proto-oncogene c-myb during definitive hematopoiesis. We show that knockdown of miR-126 results in increased c-Myb levels and promotes erythropoiesis at the expense of thrombopoiesis in vivo. We further provide evidence that specification of thrombocyte versus erythrocyte cell lineages is altered by the concerted activities of the microRNAs (miRNAs) miR-126 and miR-150. Both miRNAs are required but not sufficient individually to precisely regulate the cell fate decision between erythroid and megakaryocytic lineages during definitive hematopoiesis in vivo. These results support the notion that miRNAs not only function to provide precision to developmental programs but also are essential determinants in the control of variable potential functions of a single gene during hematopoiesis
Osservazioni sopra un articolo inserito nella Biblioteca italiana nel quale si parla di due lettere del pre. ab. Gio. Battista Baizini sul musaico di Pompei.
No full textMode of access: Internet.Sloan candidateLibrary's c.2 bound in old green decorated boards; presentation inscription from the author on front pastedown.Library's c.1 bound with: Due lettere sopra il musaico di Pompei / del pre. ab. Gio. Battista Baizini (90-B31630 c.1
Workshop report. Linear-Scaling Ab Initio Calculations: Applications and Future Directions
No full textThe study of properties and of processes in materials, frequently hinges upon understanding phenomena which originate at the atomic level. In such cases the accurate description of the interactions between large numbers of atoms is critical and in turn requires the accurate description of the electrons which play a crucial role in the bonding of atoms into molecules, surfaces and solids. This can only be achieved by solving the equations of quantum mechanics. These
equations are too complicated to solve exactly; however their solutions can be approximated by computational techniques. The most accurate ? but also most computationally demanding ? are the “ab initio” techniques which do not use any empirical adjustable parameters. Amongst them, the Density Functional Theory (DFT) formulation of quantum mechanics stands out as an excellent compromise between accuracy and computational efficiency. However, the applicability of ab initio techniques is severely limited by poor scaling: the computational effort needed to perform an ab initio calculation increases with (at least) the third power of the number of atoms, N. This cubic-scaling bottleneck limits the number of atoms we can study to a few hundred at most, even on parallel supercomputers. To overcome this length-scale limitation, a number of researchers worldwide have been pioneering the development of a novel class of ab initio methods with linear-scaling or “Order N” (O(N)) computational cost which nevertheless retain the same high level of accuracy as the conventional approaches. While physically motivated, such methods have proved particularly hard to develop as they introduce highly non-trivial localisation constraints. Nevertheless, many major obstacles have been overcome and a number of O(N)
methods (SIESTA, CONQUEST, ONETEP, etc.) for ground state DFT calculations on systems with a gap (e.g. molecules, semiconductors and insulators) are now available and have reached a state of maturity that allows them to be used to study ”real” materials. The particular focus of this workshop is therefore to look forward to what can be achieved in the next few years. Our aim is twofold: (1) As O(N) methods are currently extending the applicability of DFT calculations
to problems involving biomolecules and nanostructures they are leading to completely new levels of understanding of these systems. This CECAM meeting will give us the opportunity to make an appraisal of such large-scale simulations and their potential to connect more directly to experiments. (2) We also want to examine the options for extending linear-scaling to problems that cannot be treated by ground-state DFT but require other, more complex approaches. These include methods for treating metallic systems, excited states and wavefunction-based theories for including electronic correlation. Finding ways to transform these methods to linear-scaling
cost, and hence extent their applicability to the nano-scale, is the next big challenge that the community of developers of large-scale electronic structure methods is beginning to face. We
hope that this workshop will stimulate these major new O(N) methodological developments by bringing together the leading groups in the development of O(N) DFT methods with the leading
groups in the development of metal and excited-state or wavefunction-based methods. Strong emphasis during the workshop will be given to discussion in order to promote the exchange
of ideas between different communities (Physics, Chemistry, Materials Science, Biochemistry) which are all interested in large-scale applications with ab initio accuracy but are approaching
them from different perspectives
Ab initio studies of hydrogen desorption from low index magnesium hydride surface
No full textThe low index Magnesium hydride surfaces, MgH2(001) and MgH2(110), have been studied by ab intio Density Functional Theory (DFT) calculations. It was found that the MgH2(110) surface is more stable than MgH2(001) surface, which is in good agreement with the experimental observation. The H-2 desorption barriers vary depending on the crystalline surfaces that are exposed and also the specific H atom sites involved-they are found to be generally high, due to the thermodynamic stability of the MgH2, system, and are larger for the MgH2(001) surface. The pathway for recombinative desorption of one in-plane and one bridging H atom from the MgH2(110) surface was found to be the lowest energy barrier amongst those computed (172 KJ/mol) and is in good agreement with the experimental estimates. (c) 2006 Elsevier B.V. All rights reserved
Hur upplevs sjukskrivningsprocessen på SKF Sverige AB?
No full textDå sjukfrånvaron i Sverige länge ökat har arbetsgivarna alltmer fått upp ögonen för kostnader som sjukfrånvaron medför. Olika åtgärder har lett till att sjukfrånvaron nu börjar minska både inom den offentliga och privata sektorn. Även hos SKF Sverige AB har trenden varit positiv de senaste åren, men för att finna ytterligare metoder för att minska sjukfrånvaron, fick vi i uppdrag av SKF Sverige AB att utvärdera upplevelsen av nuvarande sjukskrivningsprocess.
Sjukskrivningsprocessen förändrades för snart två år sedan och avtalet skall nu omförhandlas. Därför har vi fått i uppdrag att utvärdera hur det har fungerat. Uppdragsgivarna, det vill säga personalavdelningen på SKF Sverige AB, undrar om sjukskrivningsprocessen upplevs fungera bra eller om det finns anledning att göra förbättringar. Därifrån fick vi vår frågeställning vilken lyder: Hur upplever chefer och medarbetare på SKF Sverige AB samt personal på Feelgood skrivningsprocessen?
Den nuvarande sjukskrivningsprocessen fungerar så att den som sjukanmäler sig skall ringa två telefonsamtal. Det ena samtalet går till berörd chef/personalombud och det andra till en legitimerad sjuksköterska på företagshälsovården, i SKF: s fall Feelgood AB.
Vi har genom en enkät- och intervjuundersökning gjort en utvärdering av medarbetarnas upplevelse av sjukskrivningsrutinen och ger förslag på förbättringar av processen. Både verkstadsanställda och tjänstemän omfattas av enkätundersökningen. Den har vi kompletterat med intervjuer med chefer med personalansvar. Dessutom intervjuade vi sjuksköterskor samt en verksamhetschef på Feelgood.
Med hjälp av induktiv metod fann vi teorier som styrker vad vi fått fram genom vår analys. I undersökningen kom vi fram till att den nuvarande sjukskrivningsprocessen, som innebär att den sjuke talar med en sjuksköterska redan första dagen generellt sett uppskattas, men att det finns potential till förbättring. Våra förslag lyder i korthet:
• Behåll nuvarande sjukskrivningsrutin, men se över om det går att effektivisera arbetet på Feelgood, till exempel om det går att frigöra någon mer till att svara på inkommande telefonsamtal så att fler som ringer kommer fram till en sjuksköterska direkt.
• Ge tydligare information till SKF: s anställda om syftet med att de skall ringa till Feelgood och vilka tjänster de tillhandahåller då felaktiga förväntningar leder till missnöje.
• Förändra utformningen av det e-postmeddelande Feelgood skickar till cheferna när någon sjukanmält sig. Lägg till individens namn i ämnesraden och en uppskattning av den förväntade frånvarotiden i meddelandet.
• Alla chefer skall ringa upp sina anställda efter två dagars frånvaro för att visa omtanke som i sin tur kan förkorta frånvarotiden.
• Alla chefer måste få någon typ av utbildning för hur dessa samtal bör genomföras och hur de i övrigt hanterar att någon i gruppen är sjuk
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