Fast Radio Bursts

The discovery of radio pulsars over a half century ago was a seminal moment in astronomy. It demonstrated the existence of neutron stars, gave a powerful observational tool to study them, and has allowed us to probe strong gravity, dense matter, and the interstellar medium. More recently, pulsar surveys have led to the serendipitous discovery of fast radio bursts (FRBs). While FRBs appear similar to the individual pulses from pulsars, their large dispersive delays suggest that they originate from far outside the Milky Way and hence are many orders-of-magnitude more luminous. While most FRBs appear to be one-off, perhaps cataclysmic events, two sources are now known to repeat and thus clearly have a longer-lived central engine. Beyond understanding how they are created, there is also the prospect of using FRBs -- as with pulsars -- to probe the extremes of the Universe as well as the otherwise invisible intervening medium. Such studies will be aided by the high implied all-sky event rate: there is a detectable FRB roughly once every minute occurring somewhere on the sky. The fact that less than a hundred FRB sources have been discovered in the last decade is largely due to the small fields-of-view of current radio telescopes. A new generation of wide-field instruments is now coming online, however, and these will be capable of detecting multiple FRBs per day. We are thus on the brink of further breakthroughs in the short-duration radio transient phase space, which will be critical for differentiating between the many proposed theories for the origin of FRBs. In this review, we give an observational and theoretical introduction at a level that is accessible to astronomers entering the field.Comment: Invited review article for The Astronomy and Astrophysics Revie

Fast Radio Bursts

The discovery of radio pulsars over a half century ago was a seminal moment in astronomy. It demonstrated the existence of neutron stars, gave a powerful observational tool to study them, and has allowed us to probe strong gravity, dense matter, and the interstellar medium. More recently, pulsar surveys have led to the serendipitous discovery of fast radio bursts (FRBs). While FRBs appear similar to the individual pulses from pulsars, their large dispersive delays suggest that they originate from far outside the Milky Way and hence are many orders-of-magnitude more luminous. While most FRBs appear to be one-off, perhaps cataclysmic events, two sources are now known to repeat and thus clearly have a longer-lived central engine. Beyond understanding how they are created, there is also the prospect of using FRBs -- as with pulsars -- to probe the extremes of the Universe as well as the otherwise invisible intervening medium. Such studies will be aided by the high implied all-sky event rate: there is a detectable FRB roughly once every minute occurring somewhere on the sky. The fact that less than a hundred FRB sources have been discovered in the last decade is largely due to the small fields-of-view of current radio telescopes. A new generation of wide-field instruments is now coming online, however, and these will be capable of detecting multiple FRBs per day. We are thus on the brink of further breakthroughs in the short-duration radio transient phase space, which will be critical for differentiating between the many proposed theories for the origin of FRBs. In this review, we give an observational and theoretical introduction at a level that is accessible to astronomers entering the field.Comment: Invited review article for The Astronomy and Astrophysics Revie

A turkey raising experiment

In order to obtain some accurate information on the factors governing the profitable rearing of turkeys, an experiment was commenced at the Poultry Research Station, Leederville, on October 12, 1955, using 54 artificially-hatched day-old Bronzewing poults, of which 29 were toms and 25 were hens

Growth of the broiler industry in W.A

THE production of poultry meat in W.A. before 1956 was only a side-line for egg producers or small, mixed farmers. Most of the meat available was made up of culled hens, first cross cockerels and some heavy breed birds

Values of commonly-used protein supplements in broiler rations

THE performances of broiler flocks in the latter part of 1964 were below standard. Low body weights and a high incidence of gizzard erosion were common on farms. It was therefore decided to test the biological valuss of the commonly-used protein supplements and also to try to find a correlation between gizzard erosion and any of the protein supplements

Chick management

A UGUST is the month when most poultry farmers get their chickens. Special attention will be needed in the coming weeks, with nutrition and disease prevention the main considerations

Controlled environment broiler houses in Western Australia

The three main features which contribute to the better returns from controlled environment broiler housing are higher density, better conversion and a reduction in labour. The higher initial cost of housing and higher running costs are more than covered by these three advantages

Comparisons of broiler rations

PELLETS are the most profitable feed for broiler chickens—but when they contain about two-thirds cereal, does it pay a country grower to pay freight on pellets when cereals are plentiful in his district

Poultry : toxic factors in protein supplements

The toxic effect of low quality and/or stale protein supplements can be a problem in the poultry industry. This article describes trials carried out to assess their importance in Western Australia

Knowledge Spillovers and Entrepreneurs’ Export Orientation

We draw on knowledge spillover literature to suggest that a country’s level of foreign direct investment (FDI) and international trade may influence the export orientation of its entrepreneurs, which in turn may relate to the country’s total level of entrepreneurial activity. Macro-level data from 34 countries during 2002–2005 indicate that a country’s outward FDI, export, and import positively affect entrepreneurs’ export orientation, but these effects differ in how fast they manifest themselves. Furthermore, the extent to which a country’s entrepreneurs engage in export-oriented activities affects the subsequent emergence of new businesses. These findings have important implications for research and practice.Export orientation;Knowledge spillovers;Country-level entrepreneurship