A Proton Synchrotron Blazar Model for Flaring in Markarian~501

(abr.) The spectral energy distribution (SED) of blazars typically has a double-humped appearance usually interpreted in terms of synchrotron self-Compton models. In proton blazar models, the SED is instead explained in terms of acceleration of protons and subsequent cascading. We discuss a variation of the Synchrotron Proton Blazar model, first proposed by M\"ucke & Protheroe (1999), in which the low energy part of the SED is mainly synchrotron radiation by electrons co-accelerated with protons which produce the high energy part of the SED mainly asproton synchrotron radiation. Using a Monte Carlo/numerical technique to simulate the interactions and subsequent cascading of the accelerated protons, we are able to fit the observed SED of Markarian 501 during the April 1997 flare. We find that the emerging cascade spectra initiated by gamma-rays from $\pi^0$ decay and by $e^\pm$ from $\mu^\pm$ decay turn out to be relatively featureless. Synchrotron radiation produced by $\mu^\pm$ from $\pi^\pm$ decay, and even more importantly by protons, and subsequent synchrotron-pair cascading, is able to reproduce well the high energy part of the SED. For this fit we find that synchrotron radiation by protons dominates the TeV emission, pion photoproduction being less important with the consequence that we predict a lower neutrino flux than in other proton blazar models.Comment: 28 pages, 8 Figures, accepted for publication in Astropart.Phy

Neutrino Emission from HBLs and LBLs

The Synchrotron Proton Blazar model is a promising model to explain high energy emission from gamma-ray loud BL Lac objects like Mkn 421. In contrast to leptonic models, the hadronic explanation of gamma-ray emission predicts ultrahigh energy neutrinos. The predicted neutrino spectra from a typical High-energy cutoff BL Lac Object (HBL) and a Low-energy cutoff BL Lac Object (LBL) are presented. We find that cooling due to muon synchrotron radiation causes a cutoff of the neutrino spectrum at $\sim 10^{18}$ eV, with the exception of $\nu_\mu$ from kaon decay which may extend to higher energies if meson production takes place in the secondary resonance region of the cross section. The impact of the neutrino output from both source populations to the diffuse neutrino background is discussed.Comment: 4 pages, 3 figures, to appear in: Proc. 27th Int. Cosmic Ray Conf., Hamburg/German

Sex Tourism and the Ethics of Contingent Responsibility

Sitting in the garden of the bar Chez Angeline in the perfumed island of Nosy Bé in Madagascarperfumed literally by culture of the Ylang-Ylang flowerI was transfixed by the singing of a raggedy minstrel with a home-made vahila, the Madagascan guitar. It was a song of warning, about AIDS, and the words were as follows: Vazaha Vazaha Vazaha Malagasy Malagasy Malagasy Hélas Hélas Hélas après le plaisir de lamour SIDA il est là Oh quelle chose SIDA SIDA nous guette SIDA nous cherche SIDA nous trouv

What Makes a Carpet Fly? Cultural Studies in the Indian Ocean

This paper aims to open up a cultural studies conversation on the Indian Ocean. Knowledge of the Indian Ocean should be born of the problems encountered in situ, rather than viewed and assessed from afar in erstwhile colonial centres. Networks and institutional links have to be created to sustain an interdisciplinary conversation leading to this decolonisation of knowledge. In investigating the interplay of commerce and culture, this paper abandons the critical separation of the two in favour of a critical engagement with forces of globalisation. As a precolonial global economy, the Indian Ocean offers considerable historical depth to the current ranking of economic powers. But within a general problematic of the theory of value, there is no doubt that cultural forms (narratives, myths religious beliefs, artefacts) are fundamental to the organising forces of trade, and not just ‘adding value’ in market transactions

Identifying gaps in primary care services: reaching the ‘unreached’

In an equitable system, the health needs of communities are matched by the services provided. Whilst a recent review of the performance of the health systems of seven countries by the Commonwealth Fund reported that ‘Australia and the U.K. continue to demonstrate superior performance’, it is important that health services provided to Australians are able to be utilised by all who need them. This RESEARCH ROUNDup investigates the concept of equity in health, endeavours to describe those who are most likely to be ‘unreached’ by primary health care services, and how they may be identified

Créolité and Réunionese Maloya: From ‘in-between’ to ‘Moorings’

At the beginning of October 2009, UNESCO announced that the culture of maloya, a genre of song and dance from the island of Réunion, would henceforth become an international heritage item. The Geneva committee, in placing this endangered form of culture under their protection, defined it as a ‘type of music, song and dance native to the island of Réunion’. There is nothing unusual in the fact that a marginal item of ‘immaterial’ culture, originating from a tiny speck of France in the Indian Ocean, should be noticed by an international organisation and ‘protected’ in this way. This discussion paper investigates versions of creole and créolité and the role of theory in the kind of advocacy that promoted maloya. It argues that ‘moorings’ (Vergès and Marimoutou), as a concept for creolisation studies, is more robust, concrete and precise than Bhabha’s ‘in-between’

A Touching and Contagious Captain Cook: Thinking History through Things

For how long can history, as it is conceived in ‘the West’, continue to attach itself to an exhausted humanism, where ‘man’ is central and all the natural and inanimate objects surrounding humans (and linked intimately to human activity) are relegated to the function of support act?This essay argues from anthropological theory that there are fundamentally different sorts of relationships that humans can entertain with non-humans, and that these relationships can have a magical force. When a monument is placed at the spot where an explorer first touched the land, does this impart a contiguous magic? On the other hand, where the stuff of history seems animated, and spreading out without clear connection to impart some small part of the aura to a doll representing the historical figure, are we not dealing with a sympathetic, contagious magic? This essay will experiment with these nonrepresentational forms of energy as they are transferred in domains associated with the figure of Lt. James Cook.What, then, is Cook when he is displaced from ‘western’ history and spread around cultures like a virus? How precarious or robust, then, are the historical certainties associated with Cook-monumentalised Kurnell and its place in time as ‘the birthplace of modern Australia’

Avoiding hospitalisation: effective primary care interventions

Ambulatory care sensitive conditions (ACSCs) “represent a range of conditions for which hospitalisation should be able to be avoided because the disease or condition has been prevented from occurring, or because individuals have had access to timely and effective primary care”. This RESEARCH ROUNDup investigates the factors that may predict avoidable hospital admissions. It also provides an overview of interventions that may be effective in reducing avoidable hospitalisations, and follows from a previous issue that examined the scope of ACSCs in Australia, and their reliability as a measure of primary health care (PHC) performance

Local community reporting models for regional primary health care organisations

Community reporting models used by primary health care organisations (PHCOs) in New Zealand, Canada (Ontario), England and Scotland were reviewed. The roles, functions and mandated community engagement requirements for these PHCOs varied, shaping the scope of their reporting. All countries included in this report recognised the importance of engaging the community in healthcare and the value of communication between service providers, service commissioners and the public. All countries were involved in receiving information from the community to inform decisions relating to the planning, design and implementation of health care services. It was, however, difficult to ascertain the extent of this involvement, and how well disadvantaged groups were included in this process