2,488 research outputs found
Evaluation of the gn-->pi-p differential cross sections in the Delta-isobar region
Differential cross sections for the process gn-->pi-p have been extracted
from MAMI-B measurements of gd-->pi-pp, accounting for final-state interaction
effects, using a diagrammatic technique taking into account the NN and piN
final-state interaction amplitudes. Results are compared to previous
measurements of the inverse process, pi-p--> ng, and recent multipole analyses.Comment: 6 pages, 4 figures. v2: Further clarifications and minor changes. A
new figure inserte
Resistance to Digitisation: Curated Memory Cards Artefact
date-added: 2015-03-24 04:16:59 +0000 date-modified: 2015-03-24 04:16:59 +0000date-added: 2015-03-24 04:16:59 +0000 date-modified: 2015-03-24 04:16:59 +0000The act of networking in any context has some element of ceremonial performance attached to it. In an analogue world these performances have historically included the act of exchanging business cards. This ‘ceremony of networking’ has the potential to be altered by the emergence of new media, especially digital technology, displacing the old ceremony of business card exchanges and disrupting what can traditional be seen as networking. The history of business cards have shown that, despite several digital alternatives, they are still resistant to digitisation and so predominantly still physical and tangible. So, we sought to explore the ceremony around giving business cards as the sharing of ‘curated memory’, to better understand how and why we share and co-create curated memories with others. Including the sharing curated memories more generally, and the changing nature of networking, arising from the ever-increasing connectivity and digital embeddedness associated with the information age. Therefore, exploring the ceremony around needing, creating, sharing and using business cards, within different contexts and cultures. Also, identifying the tasks that people are trying to perform and optimise at different stages (before, during, and after) in a range of scenarios. Also, to explore how the ceremonies of networking might be significantly altered as a result of digital media and tools. The approach of using sets of cards around Who, How, Why and Where emerged from the need for a tool that could build narratives around the considerable diversity of the disjointed scenarios of networking we observed. So, the cards provide a reference by which to share general understanding in an entertaining and easily accessible manner. Second, provides a tool to summarise narratives from the scenarios we observed, and that we could then use to create new scenarios to explore insights such as post-meeting curation of ‘shared memories’ when networking. Third, define a number of ‘games’ to help anyone explore how to better understand and utilise aspects of networking in their current approaches, and challenge them to develop new approaches. Therefore, generating debate and self-reflection on the ways players use business cards themselves
Extended Partial-Wave Analysis of piN Scattering Data
We present results from a comprehensive partial-wave analysis of pi+-p
elastic scattering and charge-exchange data, covering the region from threshold
to 2.6 GeV in the lab pion kinetic energy, employing a coupled-channel
formalism to simultaneously fit pi-p-->eta n data to 0.8 GeV. Our main result,
solution SP06, utilizes a complete set of forward and fixed-t dispersion
relation constraints applied to the piN elastic amplitude. The results of these
analyses are compared with previous solutions in terms of their resonance
spectra and preferred values for couplings and low-energy parameters.Comment: 21 pages, 11 figure
Charge-Symmetry Violation in Pion Scattering from Three-Body Nuclei
We discuss the experimental and theoretical status of charge-symmetry
violation (CSV) in the elastic scattering of pi+ and pi- on 3H and 3He.
Analysis of the experimental data for the ratios r1, r2, and R at Tpi = 142,
180, 220, and 256 MeV provides evidence for the presence of CSV. We describe
pion scattering from the three-nucleon system in terms of single- and
double-scattering amplitudes. External and internal Coulomb interactions as
well as the Delta-mass splitting are taken into account as sources of CSV.
Reasonable agreement between our theoretical calculations and the experimental
data is obtained for Tpi = 180, 220, and 256 MeV. For these energies, it is
found that the Delta-mass splitting and the internal Coulomb interaction are
the most important contributions for CSV in the three-nucleon system. The CSV
effects are rather sensitive to the choice of pion-nuclear scattering
mechanisms, but at the same time, our theoretical predictions are much less
sensitive to the choice of the nuclear wave function. It is found, however,
that data for r2 and R at Tpi = 142 MeV do not agree with the predictions of
our model, which may indicate that there are additional mechanisms for CSV
which are important only at lower energies.Comment: 26 pages of RevTeX, 16 postscript figure
Microscopic activity patterns in the Naming Game
The models of statistical physics used to study collective phenomena in some
interdisciplinary contexts, such as social dynamics and opinion spreading, do
not consider the effects of the memory on individual decision processes. On the
contrary, in the Naming Game, a recently proposed model of Language formation,
each agent chooses a particular state, or opinion, by means of a memory-based
negotiation process, during which a variable number of states is collected and
kept in memory. In this perspective, the statistical features of the number of
states collected by the agents becomes a relevant quantity to understand the
dynamics of the model, and the influence of topological properties on
memory-based models. By means of a master equation approach, we analyze the
internal agent dynamics of Naming Game in populations embedded on networks,
finding that it strongly depends on very general topological properties of the
system (e.g. average and fluctuations of the degree). However, the influence of
topological properties on the microscopic individual dynamics is a general
phenomenon that should characterize all those social interactions that can be
modeled by memory-based negotiation processes.Comment: submitted to J. Phys.
Progress on Neutron-Target Multipoles above 1 GeV
We report a new extraction of nucleon resonance couplings using pi-
photoproduction cross sections on the neutron. The world database for the
process gn-->pi-p above 1 GeV has quadrupled with the addition of new
differential cross sections from the CEBAF Large Acceptance Spectrometer (CLAS)
at Jefferson Lab in Hall B. Differential cross sections from CLAS have been
improved with a new final-state interaction determination using a diagrammatic
technique taking into account the SAID phenomenological NN and piN final-state
interaction amplitudes. Resonance couplings have been extracted and compared to
previous determinations. With the addition of these new cross sections,
significant changes are seen in the high-energy behavior of the SAID cross
sections and amplitudes.Comment: 4 pages, 3 figures, 1 table; talk given at 12th International
Workshop on Meson Production, Properties and Interaction (MESON2012), 31 May
- 5 June 2012, Krakow, Poland; will be published online in European Journal
Web of Conference
Anomalous density dependence of static friction in sand
We measured experimentally the static friction force on the surface of
a glass rod immersed in dry sand. We observed that is extremely sensitive
to the closeness of packing of grains. A linear increase of the grain-density
yields to an exponentially increasing friction force. We also report on a novel
periodicity of during gradual pulling out of the rod. Our observations
demonstrate the central role of grain bridges and arches in the macroscopic
properties of granular packings.Comment: plain tex, 6 pages, to appear in Phys.Rev.
Discovery of TUG-770: a highly potent free fatty acid receptor 1 (FFA1/GPR40) agonist for treatment of type 2 diabetes
Free fatty acid receptor 1 (FFA1 or GPR40) enhances glucose-stimulated insulin secretion from pancreatic β-cells and currently attracts high interest as a new target for the treatment of type 2 diabetes. We here report the discovery of a highly potent FFA1 agonist with favorable physicochemical and pharmacokinetic properties. The compound efficiently normalizes glucose tolerance in diet-induced obese mice, an effect that is fully sustained after 29 days of chronic dosing
Simulations of the Static Friction Due to Adsorbed Molecules
The static friction between crystalline surfaces separated by a molecularly
thin layer of adsorbed molecules is calculated using molecular dynamics
simulations. These molecules naturally lead to a finite static friction that is
consistent with macroscopic friction laws. Crystalline alignment, sliding
direction, and the number of adsorbed molecules are not controlled in most
experiments and are shown to have little effect on the friction. Temperature,
molecular geometry and interaction potentials can have larger effects on
friction. The observed trends in friction can be understood in terms of a
simple hard sphere model.Comment: 13 pages, 13 figure
Pre-Congestion Notification marking
Pre-Congestion Notification (PCN) builds on the concepts of RFC 3168, "The addition of Explicit Congestion Notification to IP". However, Pre-Congestion Notification aims at providing notification before any congestion actually occurs. Pre-Congestion Notification is applied to \ud
real-time flows (such as voice, video and multimedia streaming) in DiffServ networks. As described in [CL-DEPLOY], it enables "pre" congestion control through two procedures, flow admission control and flow pre-emption. The draft proposes algorithms that determine when a \ud
PCN-enabled router writes Admission Marking and Pre-emption Marking in a packet header, depending on the traffic level. The draft also proposes how to encode these markings. We present simulation results with PCN working in an edge-to-edge scenario using the marking algorithms described. Other marking algorithms will be investigated in the future. \u
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