3,298 research outputs found
Alien Registration- Prosser, James E. (Monticello, Aroostook County)
https://digitalmaine.com/alien_docs/34061/thumbnail.jp
Ammonia oxidation is not required for growth of Group 1.1c soil Thaumarchaeota
© FEMS 2015. FUNDING EBW is funded by Centre for Genome Enabled Biology and Medicine, University of Aberdeen.Peer reviewedPublisher PD
Tunable entanglement distillation of spatially correlated down-converted photons
We report on a new technique for entanglement distillation of the bipartite
continuous variable state of spatially correlated photons generated in the
spontaneous parametric down-conversion process (SPDC), where tunable
non-Gaussian operations are implemented and the post-processed entanglement is
certified in real-time using a single-photon sensitive electron multiplying CCD
(EMCCD) camera. The local operations are performed using non-Gaussian filters
modulated into a programmable spatial light modulator and, by using the EMCCD
camera for actively recording the probability distributions of the
twin-photons, one has fine control of the Schmidt number of the distilled
state. We show that even simple non-Gaussian filters can be finely tuned to a
~67% net gain of the initial entanglement generated in the SPDC process.Comment: 12 pages, 6 figure
On the reformulation of vehicle routing problems and scheduling problems
We can reformulate a vehicle routing problem (VRP) as an open shop scheduling problem (SSP) by representing visits as activities, vehicles as resources on the factory floor, and travel as set up costs between activities. In this paper we present two reformulations: from VRP to open shop, and the inverse, from SSP to VRP. Not surprisingly, VRP technology performs poorly on reformulated SSP's, as does scheduling technology on reformulated VRP's. We present a pre-processing transformation that "compresses" the VRP, transforming an element of travel into the duration of the visits. The compressed VRP's are then reformulated as scheduling problem, to determine if it is primarily distance in the VRP that causes scheduling technology to degrade on the reformulated problem. This is a step towards understanding the features of a problem that make it more amenable to one technology rather than another
Defining in the doing: listening and reflecting in a community–university collaboration
Defining in the doing is an approach developed by the Community University Partnership Programme (CUPP) at the University of Brighton, UK. It prioritises action and recognises the importance of practice in developing partnerships, drawing from both academic and practitioner principles in community development, community-based research and theories of social learning. This article will draw on this approach to reflect on a community–university collaboration, sustained during the Covid-19 global pandemic, between a community music organisation, a sound archive project and a doctoral researcher. Between 2019 and 2022, these practitioners brought together their expertise in sound heritage, music making, listening and sound methods, and community engagement to deliver three interlinked projects: Sounds to Keep, Sound Mosaics and Remix the Archive (RiTA). This partnership created mutual benefits by bringing together practitioner and academic knowledge and experiences. Through shared reflections, we draw out in this article the ways that the pandemic generated difficult working conditions, while also opening up space for creativity, flexibility and curiosity. But we also highlight how a defining in the doing approach is not commonly supported by the funding and administrative conditions within which we work
Graph transformations for the vehicle routing and job shop scheduling problems
The vehicle routing problem (VRP) and job shop scheduling problem (JSP) are two common combinatorial problems that can be naturally represented as graphs. A core component of solving each problem can be modeled as finding a minimum cost Hamiltonian path in a complete weighted graph. The graphs extracted from VRPs and JSPs have different characteristics however, notably in the ratio of edge weight to node weight. Our long term research question is to determine the extent to which such graph characteristics impact the performance of algorithms commonly applied to VRPs and JSPs. As a preliminary step, in this paper we investigate five transformations for complete weighted graphs that preserve the cost of Hamiltonian paths. These transformations are based on increasing node weights while reducing edge weights or the inverse. We demonstrate how the transformations affect the ratio of edge to node weight and how they change the relative weights of edges at a node. Finally, we conjecture how the different transformations will impact the performance of existing VRP and JSP solving techniques
A Parallel Branch and Bound Algorithm for the Maximum Labelled Clique Problem
The maximum labelled clique problem is a variant of the maximum clique
problem where edges in the graph are given labels, and we are not allowed to
use more than a certain number of distinct labels in a solution. We introduce a
new branch-and-bound algorithm for the problem, and explain how it may be
parallelised. We evaluate an implementation on a set of benchmark instances,
and show that it is consistently faster than previously published results,
sometimes by four or five orders of magnitude.Comment: Author-final version. Accepted to Optimization Letter
Decay of the Relative Error in the Formation of Acoustic Bullets
In a previous paper, the authors showed how to construct certain solutions of the acoustic and electromagnetic wave equations in three dimensions, which are constrained asymptotically to a narrow conical sector of an outgoing spherical shell, i.e., which behave like “bullets.” In this paper, it is shownthat, in the acoustic case, the magnitude of the relative error between the true solution and its asymptotic form decays in time according to an inverse square root law. Read More: https://epubs.siam.org/doi/10.1137/015302
The effects of heat versus cold disinfection on the Wesley-Jessen Durasoft 4 Litetint soft contact lens
An evaluation of the Wesley-Jessen 74% water Durasoft 4 LiteTint soft contact lens was made using 18 lenses on nine subjects and two pairs of control lenses. Five subjects cold disinfected the lenses and four subjects heat disinfected the lenses using Softmate PS regimens. One pair of control lenses was disinfected with each system . The results of the study show that heat disinfection can damage these lenses. Three of five pairs of lenses that were heat disinfected showed discoloration upon completion of the study. This includes one pair of control lenses which were heated once daily for 6 months, the duration of the study. All cold disinfected lenses remained normal. Other results show problems with Durasoft 4 lenses not attributable to the type of disinfection used. These problems include: difficulty in handling and determining whether inside-out or not, discomfort and severe drying symptoms, a rapid decrease in wearing time, and a tendency to accumulate deposits rapidly. Only one subject remained in the study for the 6 month duration. All others left early due to lens discomfort. Each subject was seen on a follow-up schedule and normal clinical methods were used to evaluate symptomology, fitting characteristics, and refractive changes. The results suggest that dehydration in these high water content lenses is the primary problem leading to discomfort
A model of hyphal tip growth involving microtubule-based transport
We propose a simple model for mass transport within a fungal hypha and its
subsequent growth. Inspired by the role of microtubule-transported vesicles, we
embody the internal dynamics of mass inside a hypha with mutually excluding
particles progressing stochastically along a growing one-dimensional lattice.
The connection between long range transport of materials for growth, and the
resulting extension of the hyphal tip has not previously been addressed in the
modelling literature. We derive and analyse mean-field equations for the model
and present a phase diagram of its steady state behaviour, which we compare to
simulations. We discuss our results in the context of the filamentous fungus,
Neurospora crassa.Comment: 5 pages, 5 figure
- …