3,407 research outputs found
Witnessing history: a personal view of half a century in public health
Former Chief Medical Officer Sir Kenneth Calman recently celebrated 50
years in medicine. It was a period which saw the evolution of the public
health agenda from communicable diseases to diseases of lifestyle, the
change from a hospital-orientated health service to one dominated by
community-based services, and the increasing recognition of inequalities as a
major determinant of health. This paper documents selected highlights from
his career including the Aberdeen typhoid outbreak, AIDS, bovine spongiform encephalopathy,
foot and mouth disease, radioactive fallout, the invention of computerised tomography and
magnetic resonance imaging, and draws parallels between the development of the modern
understanding of public health and the theoretical background to the science 100 years earlier
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Subaltern geographies in the plurinational state of Bolivia: the TIPNIS conflict
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Water supplies on wheatbelt farms : a general picture
In good rainfall years, farm dams provide water fo more than 50 per cent of the total stock in the wheatbelt.
Other sources include ground water supplies and the piped Comprehensive Water Scheme.
The March 1970 census included questions on farm water supplies including how farmers coped in the 1969-70 drought
Multifrequency VLA observations of the FR I radio galaxy 3C 31: morphology, spectrum and magnetic field
We present high-quality VLA images of the FR I radio galaxy 3C 31 in the
frequency range 1365 to 8440 MHz with angular resolutions from 0.25 to 40
arcsec. Our new images reveal complex, well resolved filamentary substructure
in the radio jets and tails. We also use these images to explore the spectral
structure of 3C 31 on large and small scales. We infer the apparent magnetic
field structure by correcting for Faraday rotation. Some of the intensity
substructure in the jets is clearly related to structure in their apparent
magnetic field: there are arcs of emission where the degree of linear
polarization increases, with the apparent magnetic field parallel to the ridges
of the arcs. The spectral indices are significantly steeper (0.62) within 7
arcsec of the nucleus than between 7 and 50 arcsec (0.52 - 0.57). The spectra
of the jet edges are also slightly flatter than the average for their
surroundings. At larger distances, the jets are clearly delimited from
surrounding larger-scale emission both by their flatter radio spectra and by
sharp brightness gradients. The spectral index of 0.62 in the first 7 arcsec of
3C 31's jets is very close to that found in other FR I galaxies where their
jets first brighten in the radio and where X-ray synchrotron emission is most
prominent. Farther from the nucleus, where the spectra flatten, X-ray emission
is fainter relative to the radio. The brightest X-ray emission from FR I jets
is therefore not associated with the flattest radio spectra, but with a
particle-acceleration process whose characteristic energy index is 2.24. The
spectral flattening with distance from the nucleus occurs where our
relativistic jet models require deceleration, and the flatter-spectra at the
jet edges may be associated with transverse velocity shear. (Slightly abridged)Comment: 17 pages, 13 figures, accepted for publication in MNRA
Farm dams in the wheatbelt
Of the estimated 76 000 farm dams in the wheatbelt, about 8 per cent either leak or are salt affected. The remaining 70 000 dams are capable of holding water for livestock use and can be regarded as sercicable dams.
A great many of the serviceable dams are unreliable water supplies due to the combined effects of lack of runoff from catchments, shallow depth of storage and small size of storage in relation to expected demand from livestock and evaporation loss
Cost of farm water supplies : conclusions from surveys
The Department of Agriculture, in conjunction with the Farm Water Supply Advisory Committee, has conducted farm wster supply surveys in many districts in the wheatbelt.
The aim of the surveys was to collect data to assess the existing water supplies, the potential for further water supply developments and to compare the relative difficulty of water supply development in different localities
Improved catchments for farm dams
The amounts and frequency of runoff from unimproved farmland catchments in Western Australia\u27s cereal and sheep districts are notoriously variable and unreliable. As a result many farmers have constructed improved catchments to ensure better reliability of farm dams for livestock and homestead water supplies.
Improved catchments which are used extensively on these farms are all of the compacted or bare-earth type. These include roaded catchments, flat batter dams and, to a lesser extent, scraped catchments. This article mainly discusses roaded catchments, the most common of the improved catchment types on farms
West Midlands development : water supplies in the West Midlands
IF it is practical and economic to develop both surface and underground supplies, the aim on each farm should be to provide half the farm water requirement from dams, and the other half from bores
Reducing evaporation from farm dams : a progress report December 1969
IN most seasons in the Western Australian Wheatbelt evaporation reduction techniques rate a low priority due to either the expense or the relative inefficiency of the techniques.
It is generally agreed that a similar investment in deepening or enlarging existing dams, or making new dams larger from the outset, is likely to be more profitable
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