Unusual Features of Varying Speed of Light Cosmologies

We contrast features of simple varying speed of light (VSL) cosmologies with inflationary universe models. We present new features of VSL cosmologies and show that they face problems explaining the cosmological isotropy problem. We also find that if c falls fast enough to solve the flatness and horizon problems then the quantum wavelengths of massive particle states and the radii of primordial black holes can grow to exceed the scale of the particle horizon. This may provide VSL cosmologies with a self-reproduction property. The constraint of entropy increase is also discussed. The new problems described in the this letter provide a set of bench tests for more sophisticated VSL theories to pass.Comment: expanded version, 12 page

A Strong Constraint on Ever-Present Lambda

We show that the causal set approach to creating an ever-present cosmological 'constant' in the expanding universe is strongly constrained by the isotropy of the microwave background. Fluctuations generated by stochastic lambda generation which are consistent with COBE and WMAP observations are far too small to dominate the expansion dynamics at z<1000 and so cannot explain the observed late-time acceleration of the universe. We also discuss other observational constraints from the power spectrum of galaxy clustering and show that the theoretical possibility of ever-present lambda arises only in 3+1 dimensional space-times.Comment: 5 pages, minor additions, published versio

Simple Types of Anisotropic Inflation

We display some simple cosmological solutions of gravity theories with quadratic Ricci curvature terms added to the Einstein-Hilbert lagrangian which exhibit anisotropic inflation. The Hubble expansion rates are constant and unequal in three orthogonal directions. We describe the evolution of the simplest of these homogeneous and anisotropic cosmological models from its natural initial state and evaluate the deviations they will create from statistical isotropy in the fluctuations produced during a period of anisotropic inflation. The anisotropic inflation is not a late-time attractor in these models but the rate of approach to a final isotropic de Sitter state is slow and is conducive to the creation of observable anisotropic statistical effects in the microwave background. The statistical anisotropy would not be scale invariant and the level of statistical anisotropy will grow with scale.Comment: 8pages, 3 figs v2:refs added, typos fixe

Moduli constraints on primordial black holes

The amount of late decaying massive particles (e.g., gravitinos, moduli) produced in the evaporation of primordial black holes (PBHs) of mass \Mbh\la10^9 g is calculated. Limits imposed by big-bang nucleosynthesis on the abundance of these particles are used to constrain the initial PBH mass fraction $\beta$ (ratio of PBH energy density to critical energy density at formation), as: \beta\la 5\times10^{-19} (\xp/6 10^{-3})^{-1} (\Mbh/10^9 {\rm g})^{-1/2} (\bar{\Yp}/10^{-14}); \xp is the fraction of PBH luminosity going into gravitinos or moduli, \bar{\Yp} is the upper bound imposed by nucleosynthesis on the number density to entropy density ratio of gravitinos or moduli. This notably implies that such PBHs should never come to dominate the cosmic energy density.Comment: 8 page

Key staff recruitment in small firms in the UK : a survey by Cranfield School of Management

School of Managemen

Common exercise prescription for management of weight and osteoarthritis : a systematic review : a thesis presented in partial fulfilment of the requirements for the degree of Master of Sport and Exercise at Massey University, Wellington, New Zealand

Background: Obesity and osteoarthritis are two debilitating conditions that are increasing in prevalence. Obese populations are at an increased risk for developing osteoarthritis in later life. Exercise has been shown to be successful in improving both weight status and musculoskeletal pain, yet it remains unclear if there is an exercise intervention that results in improved weight status while preventing the development of osteoarthritis. Objective: The purpose of this systematic review is to investigate the existence of a natural overlap in exercise prescription for obese and osteoarthritic populations and recommend an evidence-based exercise intervention for the management of weight and prevention of musculoskeletal pain. Methods: A structured electronic review was conducted using the following electronic databases: MEDLINE, PubMed, and SPORTDiscus. Two searches were performed using the search strings “obes*” AND “exercise” AND “interven*” AND “musculoskeletal pain OR knee pain OR hip pain” and “osteoarth*” AND “exercise” AND “interven*” AND “musculoskeletal pain OR knee pain OR hip pain”. Studies were then reviewed using inclusion/exclusion criteria (exclusion criteria: menopausal, cancer, review, obesity related co-morbidities, animal studies; inclusion criteria: studies had to be randomised controlled trials, participants aged 18-50, include non-exercise control, and outcomes must include physical function or musculoskeletal pain). Included studies were ranked by change in measured outcome variables (descending order); a summary of recommended exercise prescription was based on common prescription used in the interventions with greatest change. A Downs and Black checklist was completed for all studies included in this review to assess methodological quality. Results: Twenty-one studies met inclusion criteria and were included in this review (obesity n = 11; OA n = 7; obesity & OA n= 3). Exercise significantly improved weight status and/or musculoskeletal pain. Similarities in exercise intensity (40-80% VO2max), frequency (3 times per week), duration (30-60 minutes), and exercise mode (treadmill, cross-trainer, stationary bike, aquatic exercise) were observed between studies. Conclusion: Substantial overlap in exercise prescription for obese and OA populations exist. These findings suggest that moderate intensity exercise for 30-60 minutes, 3 times per weeks can achieve effective improvements in weight and musculoskeletal pain. Exercise and weight loss are effective treatments for obesity and musculoskeletal symptoms and should be recommended to all at-risk individuals

Images of Peru: a national cinema in crisis

A brief look at the major trends in the history of the national cinema of Peru suggests that the relationship between the development of the moving image and the onset of modernity in that country has always been awkward. Many have argued that the advent of cinema coincided in most parts of the world with the decades when modernity was already ‘at full throttle . . . a watershed moment in which a series of sweeping changes in technology and culture created distinctive new modes of thinking about and experiencing time and space’. However, the reality for the majority of Latin American countries was quite different. As Ana M. López points out, it simply is not possible to link the rise of cinema in that part of the world to ‘previous large-scale transformations of daily experience resulting from urbanization, industrialization, rationality and the technological transformation of modern life’. Such developments were only just starting to emerge, so that as cinema was launched across the world, modernity in Latin America ‘was above all a fantasy and a profound desire.

New configurations for Peruvian cinema: the rising star of Claudia Llosa

After a decade-long hiatus during which the existence of a home-grown cinema in Peru had been threatened by a lack of government and public support, a new generation of directors broke onto the scene in the twenty-first century with a distinctive approach to both the production and circulation of their films, as well as to their relationship with the ‘national’, in terms of policy, funding and audience engagement. This study takes one of those directors, Claudia Llosa, as the main case study, and considers the development of her profile as an internationally recognized Peruvian film-maker whose award-winning debut works (Madeinusa, 2006 and La Teta Asustada/Milk of Sorrow, 2009) sparked controversy and critical debate for their challenging portrayals of the Quechua culture of Peru. This article examines her successes on the international festival and commercial exhibition circuits, considers some of the scholarly and critical responses to her work, and asks what impact Llosa has had on the development of cinema in Peru through her engagement with the transnational

Deconstructive humour: subverting Mexican and Chicano stereotypes in ‘Un Día Sin Mexicanos’

a long time, US cinema developed unshakeable stereotypes of Mexican ‘otherness’, with characters of Mexican cultural and ethnic heritage stigmatised as criminals or as sensual objects of desire. Filmmakers in Mexico, meanwhile, treated Mexican Americans as misfits who belonged nowhere, or ignored them and their complex experience completely. The emergence of a distinct ‘Chicano cinema’ in the 1960s allowed for the development of a more powerful set of images of Mexican Americans, exploiting the very tool of communication that had been used against them, and for the circulation of a more productive and reflective dialogue around the questions of identity, agency and resistance that arise. This article focuses on the use of humour as a subversive tool to deconstruct certain myths and stereotypes of Mexican and, to a certain extent, Mexican American (or, Chicano) identity in Sergio Arau’s popular debut feature, Un Día Sin Mexicanos (2004). The “Mexicans” referred to in the film’s title and used in much of its dialogue stand metonymically for all Hispanic immigrants, whether recently arrived, or born in the US and of Hispanic descent, including Chicanos. Its narrative was inspired by the introduction of controversial anti-immigration legislation in California in 1994, and the Californian State is here made representative of anywhere in the US where there is a Mexican or Chicano population. This essay situates the film within the context of a growing Chicano population in the US and a high level of immigration from Mexico itself. It asks to what extent the feature version, which takes the form of satire, offers a critique of the Mexican immigrant experience, and of discrimination more broadly against Hispanic minorities. In so doing, it explores the ways in which the politics of resistance that are so often aligned with these experiences are inscribed in its narrative form

The Copernican Principle in Compact Spacetimes

Copernicus realised we were not at the centre of the universe. A universe made finite by topological identifications introduces a new Copernican consideration: while we may not be at the geometric centre of the universe, some galaxy could be. A finite universe also picks out a preferred frame: the frame in which the universe is smallest. Although we are not likely to be at the centre of the universe, we must live in the preferred frame (if we are at rest with respect to the cosmological expansion). We show that the preferred topological frame must also be the comoving frame in a homogeneous and isotropic cosmological spacetime. Some implications of topologically identifying time are also discussed.Comment: 5 page