Perceptions and experience of employment regulation in UK small firms

The view that excessive regulation constrains small business growth has been a persistent theme within business and policy communities, although recent studies have demonstrated the actual effects of regulation to be relatively modest. A prior small-scale study proposed four reasons why employment legislation does 'not damage' small firms. We attempt to assess the robustness of these propositions in a large-scale survey of 16 779 small firms. Results provide empirical support for three propositions. Firstly, perceived dissatisfaction masks actual effects. Secondly, competitive conditions mediate regulatory effects; however, even resource-constrained firms reported few negative effects. Thirdly, informality eases regulatory impact. Results failed to confirm that older laws are 'routinised'. Length of time as a business owner was found to be more influential than age of regulation, with owners who have been in business for many years having a longer 'window of exposure' increasing their likelihood of experiencing negative and positive effects

Cooper pair dispersion relation for weak to strong coupling

Cooper pairing in two dimensions is analyzed with a set of renormalized equations to determine its binding energy for any fermion number density and all coupling assuming a generic pairwise residual interfermion interaction. \ Also considered are Cooper pairs (CPs) with nonzero center-of-mass momentum (CMM)--usually neglected in BCS theory--and their binding energy is expanded analytically in powers of the CMM up to quadratic terms. A Fermi-sea-dependent {\it linear} term in the CMM dominates the pair excitation energy in weak coupling (also called the BCS regime) while the more familiar quadratic term prevails in strong coupling (the Bose regime). The crossover, though strictly unrelated to BCS theory {\it per se,} is studied numerically as it is expected to play a central role in a model of superconductivity as a Bose-Einstein condensation of CPs where the transition temperature vanishes for all dimensionality $d\leq 2$ for quadratic dispersion, but is {\it nonzero} for all $d\geq 1$ for linear dispersion.Comment: 11 pages plus 3 figures, revised version accepted in Physical Review

Linear to quadratic crossover of Cooper pair dispersion relation

Cooper pairing is studied in three dimensions to determine its binding energy for all coupling using a general separable interfermion interaction. Also considered are Cooper pairs (CPs) with nonzero center-of-mass momentum (CMM). A coupling-independent {\it linear} term in the CMM dominates the pair excitation energy in weak coupling and/or high fermion density, while the more familiar quadratic term prevails only in the extreme low-density (i.e., vacuum) limit for any nonzero coupling. The linear-to-quadratic crossover of the CP dispersion relation is analyzed numerically, and is expected to play a central role in a model of superconductivity (and superfluidity) simultaneously accommodating a BCS condensate as well as a Bose-Einstein condensate of CP bosons.Comment: 13 pages plus 2 figure

Ratios of Elastic Scattering of Pions from 3H and 3He

We have measured the elastic-scattering ratios of normalized yields for charged pions from 3H and 3He in the backward hemisphere. At 180 MeV, we completed the angular distribution begun with our earlier measurements, adding six data points in the angular range of 119 deg to 169 deg in the pi-nucleus center of mass. We also measured an excitation function with data points at 142, 180, 220, and 256 MeV incident pion energy at the largest achievable angle for each energy between 160 deg and 170 deg in the pi-nucleus center of mass. This excitation function corresponds to the energies of our forward-hemisphere studies. The data, taken as a whole, show an apparent role reversal of the two charge-symmetric ratios r1 and r2 in the backward hemisphere. Also, for data > 100 deg we observe a strong dependence on the four-momentum transfer squared (-t) for all of the ratios regardless of pion energy or scattering angle, and we find that the superratio R data match very well with calculations based on the forward-hemisphere data that predicts the value of the difference between the even-nucleon radii of 3H and 3He. Comparisons are also made with recent calculations incorporating different wave functions and double scattering models.Comment: RevTex 8pages, 12 figure file

Gravitational collapse of a Hagedorn fluid in Vaidya geometry

The gravitational collapse of a high-density null charged matter fluid, satisfying the Hagedorn equation of state, is considered in the framework of the Vaidya geometry. The general solution of the gravitational field equations can be obtained in an exact parametric form. The conditions for the formation of a naked singularity, as a result of the collapse of the compact object, are also investigated. For an appropriate choice of the arbitrary integration functions the null radial outgoing geodesic, originating from the shell focussing central singularity, admits one or more positive roots. Hence a collapsing Hagedorn fluid could end either as a black hole, or as a naked singularity. A possible astrophysical application of the model, to describe the energy source of gamma-ray bursts, is also considered.Comment: 14 pages, 2 figures, to appear in Phys. Rev.

Mosquito Net Use in an Artisanal East African Fishery

Widespread, anecdotal reports of the use of bed nets designed for malaria control (“mosquito nets”) in artisanal fisheries have led to concern from health and natural resource management sectors. However, mosquito net fishing (MNF) may play an important role in the livelihoods of artisanal fishers, an aspect not yet investigated. At a coastal Kenyan site among Giriama fishers, nearly half of homesteads interviewed used mosquito nets as fishing gear, targeting juvenile fish and prawns for subsistence and sale. The majority of mosquito net (MN) fishers here were men, suggesting that the assumption that MNF is a female activity is not valid in this case. However, MN use for fishing at this site is unlikely to impact malaria protection as fishers used old or surplus nets. Respondents perceived both positive aspects of MNF (e.g., food and income) and negative aspects (e.g., impact on fishery). As mosquito nets are widely available, they may enable new entrants to access fisheries. There is a critical need to review current management responses, which predominately focus on banning the practice, and instead promote integrated strategies for sustainable livelihoods

Fitting the integrated Spectral Energy Distributions of Galaxies

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters