588 research outputs found
The phase free, longitudinal, magnetic component of vacuum electromagnetism
A charge moving in a reference laboratory system with constant velocity
{\bf V} in the -axis produces in the -axis a longitudinal, phase free,
vacuum magnetic field which is identified as the radiated field
of Evans, Vigier and others.Comment: ReVTeX file, 7pp., no figure
Cyclical strain improves artificial equine tendon constructs in vitro
Tendon injuries are a common cause of morbidity in humans. They also occur frequently in horses and the horse provides a relevant, large animal model in which to test novel therapies. To develop novel cell therapies that can aid tendon regeneration and reduce subsequent reâinjury rates, the mechanisms that control tendon tissue regeneration and matrix remodelling need to be better understood. Whilst a range of chemical cues have been explored (growth factors, media etc.), the influence of the mechanical environment on tendon cell culture has yet to be fully elucidated. To mimic the in vivo environment, in this study we have utilised a novel and affordable, customâmade bioreactor to apply a cyclical strain to tendonâlike constructs generated in 3âdimensional (3D) culture by equine tenocytes. Dynamic shear analysis (DSA), dynamic scanning calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy were used to determine the mechanical and chemical properties of the resulting tendonâlike constructs. Our results demonstrate that equine tenocytes exposed to a 10% cyclical strain have an increased amount of collagen gel contraction after 7 and 8 days of culture compared to cells cultured in 3D in the absence of external strain. While all the tendonâlike constructs have a very similar chemical composition to native tendon, the application of strain improves their mechanical properties. We envisage these results will contribute towards the development of improved biomimetic artificial tendon models for the development of novel strategies for equine regenerative therapies
Spurious states in the Faddeev formalism for few-body systems
We discuss the appearance of spurious solutions of few-body equations for
Faddeev amplitudes. The identification of spurious states, i.e., states that
lack the symmetry required for solutions of the Schroedinger equation, as well
as the symmetrization of the Faddeev equations is investigated. As an example,
systems of three and four electrons, bound in a harmonic-oscillator potential
and interacting by the Coulomb potential, are presented.Comment: 11 pages. REVTE
Continuous Spectrum of Automorphism Groups and the Infraparticle Problem
This paper presents a general framework for a refined spectral analysis of a
group of isometries acting on a Banach space, which extends the spectral theory
of Arveson. The concept of continuous Arveson spectrum is introduced and the
corresponding spectral subspace is defined. The absolutely continuous and
singular-continuous parts of this spectrum are specified. Conditions are given,
in terms of the transposed action of the group of isometries, which guarantee
that the pure-point and continuous subspaces span the entire Banach space. In
the case of a unitarily implemented group of automorphisms, acting on a
-algebra, relations between the continuous spectrum of the automorphisms
and the spectrum of the implementing group of unitaries are found. The group of
spacetime translation automorphisms in quantum field theory is analyzed in
detail. In particular, it is shown that the structure of its continuous
spectrum is relevant to the problem of existence of (infra-)particles in a
given theory.Comment: 31 pages, LaTeX. As appeared in Communications in Mathematical
Physic
Structural and dynamical properties of superfluid helium: a density functional approach
We present a novel density functional for liquid 4He, properly accounting for
the static response function and the phonon-roton dispersion in the uniform
liquid. The functional is used to study both structural and dynamical
properties of superfluid helium in various geometries. The equilibrium
properties of the free surface, droplets and films at zero temperature are
calculated. Our predictions agree closely to the results of ab initio Monte
Carlo calculations, when available. The introduction of a phenomenological
velocity dependent interaction, which accounts for backflow effects, is
discussed. The spectrum of the elementary excitations of the free surface and
films is studied.Comment: 37 pages, REVTeX 3.0, figures on request at [email protected]
Dietary and/or physical activity interventions in women with overweight or obesity prior to fertility treatment : protocol for a systematic review and individual participant data meta-analysis
Funding Information: This project is partly supported by the Centre for Research Excellence in Women's Health in Reproductive Life (app1171592) through a project support grant. RW is supported by a National Health and Medical Research Council (NHRMC) Investigator grant (2009767). LM is supported by a Heart Foundation Future Leader Fellowship. Funding Information: AH reports consultancy for Ferring with respect to the development of a lifestyle app. BWM is supported by an NHMRC Investigator grant (GNT1176437). BWM reports personal fees from ObsEva and Merck, and travel support from Merck, outside the submitted work. RW reports grants from the NHMRC. TM is supported by a Future Leader in Diabetes Award from the European Foundation for the Study of Diabetes/Novo Nordisk Foundation (NNF19SA058975) and grants from the regional health authority in Central Norway. ATK reports personal fees from Merck for lectures. The other authors do not have competing interest to declare. Funding Information: This project is partly supported by the Centre for Research Excellence in Womenâs Health in Reproductive Life (app1171592) through a project support grant. RW is supported by a National Health and Medical Research Council (NHRMC) Investigator grant (2009767). LM is supported by a Heart Foundation Future Leader Fellowship. Publisher Copyright: © Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Peer reviewedPublisher PD
Young and Intermediate-age Distance Indicators
Distance measurements beyond geometrical and semi-geometrical methods, rely
mainly on standard candles. As the name suggests, these objects have known
luminosities by virtue of their intrinsic proprieties and play a major role in
our understanding of modern cosmology. The main caveats associated with
standard candles are their absolute calibration, contamination of the sample
from other sources and systematic uncertainties. The absolute calibration
mainly depends on their chemical composition and age. To understand the impact
of these effects on the distance scale, it is essential to develop methods
based on different sample of standard candles. Here we review the fundamental
properties of young and intermediate-age distance indicators such as Cepheids,
Mira variables and Red Clump stars and the recent developments in their
application as distance indicators.Comment: Review article, 63 pages (28 figures), Accepted for publication in
Space Science Reviews (Chapter 3 of a special collection resulting from the
May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space
Age
20 years of the Atlantic Meridional Transect - AMT
The AMT (www.amt-uk.org) is a multidisciplinary programme which undertakes biological, chemical, and physical oceanographic research during an annual voyage between the UK and a destination in the South Atlantic such as the Falkland Islands, South Africa, or Chile. This transect of >12,000 km crosses a range of ecosystems from subpolar to tropical, from euphotic shelf seas and upwelling systems, to oligotrophic mid-ocean gyres. The year 2015 has seen two milestones in the history of the AMT: the achievement of 20 years of this unique ocean going programme and the departure of the 25th cruise on the 15th of September. Both of these events were celebrated in June this year with an open science conference hosted by the Plymouth Marine Laboratory (PML) and will be further documented in a special issue of Progress in Oceanography which is planned for publication in 2016. Since 1995, the 25 research cruises have involved 242 sea-going scientists from 66 institutes representing 22 countries. AMT was designed from the outset to be a collaborative programme. It was originally conceived by Jim Aiken, Patrick Holligan, Roger Harris, and Dave Robins with Chuck McClain and Chuck Trees at NASA to test and ground truth satellite algorithms of ocean color. The opportunities offered by this initiative meant that this series of repeated biannual cruises rapidly developed into a coordinated study of ocean biodiversity, biogeochemistry, and ocean/atmosphere interactions
Engineering serendipity: high-throughput discovery of materials that resist bacterial attachment
Controlling the colonisation of materials by microorganisms is important in a wide range of industries and clinical settings. To date, the underlying mechanisms that govern the interactions of bacteria with material surfaces remain poorly understood, limiting the ab initio design and engineering of biomaterials to control bacterial attachment. Combinatorial approaches involving high-throughput screening have emerged as key tools for identifying materials to control bacterial attachment. The hundreds of different materials assessed using these methods can be carried out with the aid of computational modelling. This approach can develop an understanding of the rules used to predict bacterial attachment to surfaces of non-toxic synthetic materials. Here we outline our view on the state of this field and the challenges and opportunities in this area for the coming years
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