2,553 research outputs found
Crystallization and melting of bacteria colonies and Brownian Bugs
Motivated by the existence of remarkably ordered cluster arrays of bacteria
colonies growing in Petri dishes and related problems, we study the spontaneous
emergence of clustering and patterns in a simple nonequilibrium system: the
individual-based interacting Brownian bug model. We map this discrete model
into a continuous Langevin equation which is the starting point for our
extensive numerical analyses. For the two-dimensional case we report on the
spontaneous generation of localized clusters of activity as well as a
melting/freezing transition from a disordered or isotropic phase to an ordered
one characterized by hexagonal patterns. We study in detail the analogies and
differences with the well-established Kosterlitz-Thouless-Halperin-Nelson-Young
theory of equilibrium melting, as well as with another competing theory. For
that, we study translational and orientational correlations and perform a
careful defect analysis. We find a non standard one-stage, defect-mediated,
transition whose nature is only partially elucidated.Comment: 13 Figures. 14 pages. Submitted to Phys. Rev.
Augmented-reality template guided transorbital approach for intradural tumors.
For minimally invasive approaches to a deep-lying skull base lesion, the bone opening must be precisely placed and adequately wide to accomplish the surgical goal. Surgical rehearsal in virtual reality (VR) can generate navigation-integrated augmented reality (AR) templates to ensure precise surgical openings. In this video, the authors used AR templates for the transpalpebral, transorbital approach for intradural tumors. VR renderings of patient-specific anatomy were used in surgical rehearsal. The optimal openings were saved and, at surgery, projected into the eyepiece of the navigation-tracked microscope. The template enhanced the planning of the incision and soft-tissue exposure and guided the drill toward the target. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21172
Правові засади здійснення діяльності зі спільного інвестування
We describe the expression of the bispecific antibody biscFv2429 in transgenic suspension culture cells and tobacco plants. biscFv2429 consists of two single chain antibodies, scFv24 and scFv29, connected by the Trichoderma reesi cellobiohydrolase I linker. biscFv2429 binds two epitopes of tobacco mosaic virus (TMV): the scFv24 domain recognizes neotopes of intact virions, and the scFv29 domain recognizes a cryptotope of the TMV coat protein monomer. biscFv2429 was functionally expressed either in the cytosol (biscFv2429-cyt) or targeted to the apoplast using a murine leader peptide sequence (biscFv2429-apoplast). A third construct contained the C-terminal KDEL sequence for retention in the ER (biscFv2429-KDEL). Levels of cytoplasmic biscFv2429 expression levels were low. The highest levels of antibody expression were for apoplast targeted biscFv2429-apoplast and ER retained biscFv2429-KDEL, which reached a maximum expression level of 1.65% total soluble protein in transgenic plants. P lant expressed biscFv2429 retained both epitope specificities, and bispecificity and bivalency were confirmed by ELISA and surface plasmon resonance analysis. This study establishes plant cells as an expression system for bispecific single chain antibodies for use in medical and biological applications
Territorial Tactics: The Socio-spatial Significance of Private Policing Strategies in Cape Town
This paper analyses the policing strategies of private security companies operating in urban space. An existing literature has considered the variety of ways that territory becomes of fundamental importance in the work of public police forces. However, this paper examines territory in the context of private security companies. Drawing on empirical research in Cape Town, it examines how demarcated territories become key subjects in private policing. Private security companies are responsible for a relatively small section of the city, while in contrast the public police ultimately have to see city space as a whole. Hence, private policing strategy becomes one of displacement, especially of so-called undesirables yielding a patchworked public space associated with private enclaves of consumption. The conclusions signal the historical resonances and comparative implications of these political-legal-security dynamics. © 2013 Urban Studies Journal Limited
Graph isomorphism for (H1,H2)-free graphs : an almost complete dichotomy.
We almost completely resolve the computational complexity
of Graph Isomorphism for classes of graphs characterized by two forbidden
induced subgraphs H1 and H2. Schweitzer settled the complexity of
this problem restricted to (H1;H2)-free graphs for all but a nite number
of pairs (H1;H2), but without explicitly giving the number of open cases.
Grohe and Schweitzer proved that Graph Isomorphism is polynomialtime
solvable on graph classes of bounded clique-width. By combining
known results with a number of new results, we reduce the number of
open cases to seven. By exploiting the strong relationship between Graph
Isomorphism and clique-width, we simultaneously reduce the number of
open cases for boundedness of clique-width for (H1;H2)-free graphs to
ve
The reaction and the magnetic dipole moment of the resonance
The reaction has been measured with
the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI for
energies between = 1221--1331 MeV. Cross sections differential in
angle and energy have been determined for all particles in the final state in
three bins of the excitation energy. This reaction channel provides access to
the magnetic dipole moment of the resonance and, for the
first time, a value of has been extracted
Photoproduction of eta-mesic 3He
The photoproduction of eta-mesic 3He has been investigated using the TAPS
calorimeter at the Mainz Microtron accelerator facility MAMI. The total
inclusive cross section for the reaction gamma+3He->eta+X has been measured for
photon energies from threshold to 820 MeV. The total and angular differential
coherent eta cross sections have been extracted up to energies of 745 MeV. A
resonance-like structure just above the eta production threshold with an
isotropic angular distribution suggests the existence of a resonant quasi-bound
state. This is supported by studies of a competing decay channel of such a
quasi-bound eta-mesic nucleus into pi^0+p+X. A binding energy of (-4.4+-4.2)
MeV and a width of (25.6+-6.1) MeV is deduced for the quasi-bound eta-mesic
state in 3He.Comment: v1: 4 pages, 4 figures, submitted to PRL; v2: minor revisions and
corrections, new figure added, 4 pages, 5 figs; v3: minor change
In-medium modifications of the interaction in photon-induced reactions
Differential cross sections of the reactions
and have been measured for several
nuclei (H,C, and Pb) at an incident-photon energy of
=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS
spectrometer. A significant nuclear-mass dependence of the
invariant-mass distribution is found in the channel. This
dependence is not observed in the channel and is
consistent with an in-medium modification of the interaction in the
==0 channel. The data are compared to -induced measurements and to
calculations within a chiral-unitary approach
Children of prisoners: exploring the impact of families' reappraisal of the role and status of the imprisoned parent on children's coping strategies
Qualitative data from a larger study on the impact of parental imprisonment in four countries found that children of prisoners face fundamentally similar psychological and social challenges. The ways that children cope, however, are influenced by the interpretative frame adopted by the adults around them, and by how issues of parental imprisonment are talked about in their families. This article argues that families have to reappraise their view of the imprisoned parent and then decide on their policy for how to deal with this publicly. Their approach may be based on openness and honesty or may emphasise privacy and secrecy, or a combination of these. Children are likely to be influenced by their parents'/carers' views, although these may cause conflict for them. Where parents/carers retain a positive view of the imprisoned parent, children are likely to benefit; where parents/carers feel issues of shame and stigma acutely, this is likely to be transmitted to their children. This is important for social workers and practitioners involved in supporting prisoners' families and for parenting programmes
Planning and Leveraging Event Portfolios: Towards a Holistic Theory
This conceptual paper seeks to advance the discourse on the leveraging and legacies of events by examining the planning, management, and leveraging of event portfolios. This examination shifts the common focus from analyzing single events towards multiple events and purposes that can enable cross-leveraging among different events in pursuit of attainment and magnification of specific ends. The following frameworks are proposed: (1) event portfolio planning and leveraging, and (2) analyzing events networks and inter-organizational linkages. These frameworks are intended to provide, at this infancy stage of event portfolios research, a solid ground for building theory on the management of different types and scales of events within the context of a portfolio aimed to obtain, optimize and sustain tourism, as well as broader community benefits
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