Determining the Gluon Distributions in the Proton and Photon from Two-Jet Production at HERA

Two-jet production from the direct photon contribution at HERA is a sensitive measure of the small-$x$ gluon in the proton. We propose measurements of ratios of the jet cross-sections which will clearly distinguish between gluons with or without singular behaviour at small $x$. Furthermore, we show that analogous ratio measurements for the resolved photon contribution provide a sensitive way of determining the gluon distribution in the photon.Comment: Rutherford Appleton Laboratory report RAL-93-071 7 pages 3 figs Fig2 and Fig3 included as psfile

The complete radiative corrections to the gaugino and Higgsino masses in the Minimal Supersymmetric Model

We determine the radiative corrections to the masses of the gauginos and Higgsinos in the MSSM, including all sectors of the theory in a one-loop calculation in the on-mass-shell renormalization scheme. We find that a gluino which is massless at tree level receives a mass of between 0 and 3 GeV, primarily due to the top/stop contribution. This radiatively generated mass depends directly on the off-diagonal element of the squark mass matrix. In the case of a massive gluino, its mass receives typically large corrections, as large as 40\% for a 125 GeV gluino. We find that the contributions to the neutralino and chargino mass corrections from the gauge/Higgs/gaugino/Higgsino sector are typically +-1%. The lightest neutralino, which can receive corrections larger than 25%, receives 5% corrections over most of the parameter space. We combine our results with the results of LEP and CDF searches to obtain the lower bounds on the neutralino and chargino masses at one-loop. We also demonstrate how the radiative corrections affect the presently excluded region of parameter space.Comment: 16 pages, JHU-TIPAC-940001, PURD-TH-94-04. 6 uuencoded postscript figures included. Uncomment the line "%\input epsf" to embed the figures in the tex

Management learning at the speed of life:Designing reflective, creative, and collaborative spaces for millenials

This paper introduces the concept of "management learning at the speed of life" as a metaphor to inspire millenials. Millenials may face three major problems in relation to management learning: lack of concentration, lack of engagement, and lack of socialization. Management learning at the speed of life addresses these potential problems through three dimensions: reflective, creative, and collaborative learning. This paper illustrates the benefits of reflective, creative, and collaborative spaces for millenials using practices from leadership and personal development courses that were offered over seven years in Canada, Turkey, and the UK. These courses incorporated the latest technology that brought the course activities up to the speed of life

Manufacturability of AlSi10Mg overhang structures fabricated by laser powder bed fusion

© 2018 Elsevier Ltd The main advantage of laser powder bed fusion (LPBF) is its use for directly manufacturing metal components with highly complex geometries. But the LPBF manufacture of overhang structures, also known as downward-facing surfaces, is a challenge because of the possibility of incurring distortion and dross defects. This paper presents a systematic examination of the manufacturability and structural integrity of AlSi10Mg overhang structures fabricated by LPBF using computational and experimental techniques. The experimental and simulation results indicate that the use of support structures facilitates the manufacturability and structural integrity of both full-circle and half-circle overhang structures. The influence of supports on circularity was found to be more beneficial as the diameter increased above 15 mm. The experiments also suggest that the use of supports plays a significant role in maintaining mechanical performance by successful fabrication of downward-facing surfaces free of dross defects. From a design perspective, small overhang features are preferable to large overhangs, especially when support removal is impractical. This study significantly contributes to design for metal additive manufacturing by providing an improved understanding of the manufacturability of overhang structures in applications intended for lightweight structural performance

Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V_2O_3

Magnetic correlations in all four phases of pure and doped vanadium sesquioxide V_2O_3 have been examined by magnetic thermal neutron scattering. While the antiferromagnetic insulator can be accounted for by a Heisenberg localized spin model, the long range order in the antiferromagnetic metal is an incommensurate spin-density-wave, resulting from a Fermi surface nesting instability. Spin dynamics in the strongly correlated metal are dominated by spin fluctuations in the Stoner electron-hole continuum. Furthermore, our results in metallic V_2O_3 represent an unprecedentedly complete characterization of the spin fluctuations near a metallic quantum critical point, and provide quantitative support for the SCR theory for itinerant antiferromagnets in the small moment limit. Dynamic magnetic correlations for energy smaller than k_BT in the paramagnetic insulator carry substantial magnetic spectral weight. However, the correlation length extends only to the nearest neighbor distance. The phase transition to the antiferromagnetic insulator introduces a sudden switching of magnetic correlations to a different spatial periodicity which indicates a sudden change in the underlying spin Hamiltonian. To describe this phase transition and also the unusual short range order in the paramagnetic state, it seems necessary to take into account the orbital degrees of freedom associated with the degenerate d-orbitals at the Fermi level in V_2O_3.Comment: Postscript file, 24 pages, 26 figures, 2 tables, accepted by Phys. Rev.

Beak and feather disease virus in wild and captive parrots: an analysis of geographic and taxonomic distribution and methodological trends

Psittacine beak and feather disease (PBFD) has emerged in recent years as a major threat to wild parrot populations and is an increasing concern to aviculturists and managers of captive populations. Pathological and serological tests for screening for the presence of beak and feather disease virus (BFDV) are a critical component of efforts to manage the disease and of epidemiological studies. Since the disease was first reported in the mid-1970s, screening for BFDV has been conducted in numerous wild and captive populations. However, at present, there is no current and readily accessible synthesis of screening efforts and their results. Here, we consolidate information collected from 83 PBFD- and BFDV-based publications on the primary screening methods being used and identify important knowledge gaps regarding potential global disease hotspots. We present trends in research intensity in this field and critically discuss advances in screening techniques and their applications to both aviculture and to the management of threatened wild populations. Finally, we provide an overview of estimates of BFDV prevalence in captive and wild flocks alongside a complete list of all psittacine species in which the virus has been confirmed. Our evaluation highlights the need for standardised diagnostic tests and more emphasis on studies of wild populations, particularly in view of the intrinsic connection between global trade in companion birds and the spread of novel BFDV strains into wild populations. Increased emphasis should be placed on the screening of captive and wild parrot populations within their countries of origin across the Americas, Africa and Asia

Gelatin-Hyaluronic Acid Hydrogels with Tuned Stiffness to Counterbalance Cellular Forces and Promote Cell Differentiation

[EN] Cells interact mechanically with their environment, exerting mechanical forces that probe the extracellular matrix (ECM). The mechanical properties of the ECM determine cell behavior and control cell differentiation both in 2D and 3D environments. Gelatin (Gel) is a soft hydrogel into which cells can be embedded. This study shows significant 3D Gel shrinking due to the high traction cellular forces exerted by the cells on the matrix, which prevents cell differentiation. To modulate this process, Gel with hyaluronic acid (HA) has been combined in an injectable crosslinked hydrogel with controlled Gel-HA ratio. HA increases matrix stiffness. The addition of small amounts of HA leads to a significant reduction in hydrogel shrinking after cell encapsulation (C2C12 myoblasts). We show that hydrogel stiffness counterbalanced traction forces of cells and this was decisive in promoting cell differentiation and myotube formation of C2C12 encapsulated in the hybrid hydrogels.The authors are grateful for the financial support received from the Spanish Ministry through the MAT2013-46467-C4-1-R project (including the FEDER financial support), the BES-2011-046144, and the EEBB-I-14-08725 grants. CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. M.S.S. acknowledges ERC through HealInSynergy 306990.Poveda Reyes, S.; Moulisova, V.; Sanmartín Masiá, EDR.; Quintanilla-Sierra, L.; Salmerón Sánchez, M.; Gallego Ferrer, G. (2016). Gelatin-Hyaluronic Acid Hydrogels with Tuned Stiffness to Counterbalance Cellular Forces and Promote Cell Differentiation. Macromolecular Bioscience. 16(9):1311-1324. https://doi.org/10.1002/mabi.201500469S1311132416

Variability in the use of mobile ICTs by homeworkers and its consequences for boundary management and social isolation

We examine how the use of mobile information and communication technologies (ICTs) among self-employed homeworkers affects their experience of work, focusing particularly on where work is carried out, how the work/non-work boundary is managed, and people's experiences of social and professional isolation. Positively, their use enhanced people's sense of spatio-temporal freedom by allowing them to leave the home without compromising their work availability. This also helped reduce people's feelings of social isolation. More negatively, their use enhanced people's sense of 'perpetual contact', creating a sense that work was difficult to escape from. However, the extent to which mobile ICTs were used, and the extent to which their impact on people's experiences of work were understood, were found to vary significantly, highlighting the agency that users have with regard to technology use. The findings are framed by combining Nippert-Eng's boundary work theory, with an 'emergent process' perspective on socio-technical relations