To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Magic squares have long been popular in recreational mathematics. Their potential for introducing students to ideas in linear algebra was recognised over forty years ago in  and later in . More recently they have proved to be a fascinating topic for undergraduate exploration, especially when students have access to a computer algebra package . Some results on powers of magic square matrices can be found in ,  and . (Readers who google the title ‘Odd magic powers’ of Thompson’s paper  will be treated to a wide variety of non-mathematical exotica!)
The Glasgow area has a combination of highly variable superficial deposits and a legacy of heavy industry, quarrying and mining. These factors create complex foundation and hydrological conditions, influencing the movement of contaminants through the subsurface and giving rise locally to unstable ground conditions. Digital geological three-dimensional models developed by the British Geological Survey are helping to resolve the complex geology underlying Glasgow, providing a key tool for planning and environmental management. The models, covering an area of 3200km2 to a depth of 1.2km, include glacial and post-glacial deposits and the underlying, faulted Carboniferous igneous and sedimentary rocks. Control data, including 95,000 boreholes, digital mine plans and published geological maps, were used in model development. Digital outputs from the models include maps of depth to key horizons, such as rockhead or depth to mine workings. The models have formed the basis for the development of site-scale high-resolution geological models and provide input data for a wide range of other applications from groundwater modelling to stochastic lithological modelling.
Recently a friend kindly made me a birthday card whose background consisted of rows and rows of digits, some 3000 in all. There appeared to be no discernible pattern in the digits. Perhaps they had been taken from a table of random numbers. They were certainly not the opening digits of the decimal parts of π or , although they might, so far as I knew, have been consecutive digits of either number in some section remote from the decimal point.
On thinking about this, I realised that they must be the opening digits of the decimal part of the square root of some whole number. Indeed, they must be the opening digits of the decimal parts of the square roots of infinitely many positive integers. It is remarkably easy to prove this and the argument is simple enough to be appreciated and understood in school classrooms at GCSE level.
A QTL (TM-QTL) identified on ovine chromosome 18 (Walling et al., 2004), which increases loin muscle depth by 4-8% in UK Texel sheep, is of interest for the sheep industry as a potential means to increase carcass value. Since the contribution of Texel genes to the UK slaughter generation is generally through use of Texel sires to produce crossbred slaughter lambs (e.g. Texel x Mule lambs), it is necessary to verify the effects of the TM-QTL on loin muscularity and other carcass traits in such crossbred progeny of Texel sires before explotiation of the TM-QTL in commercial sheep populations.
Muscularity of lamb carcasses, which is defined as the depth of muscle relative to dimensions of the skeleton (De Boer et al., 1974), is a commercially important trait in many countries. An objective index of muscularity was defined by Purchas et al. (1991) based on the weights of the muscles around a bone and the bone length. Jones et al. (2002) proposed an objective index to assess in vivo the shape of the muscle in the hind leg using X-ray Computed Tomography (CT), which had a phenotypic correlation of 0.63 with dissection measures of muscularity, as described by Purchas et al. (1991).
X-ray computed tomography (CT) measurements of live sheep have been used to predict carcass composition very accurately (Macfarlane et al., 2006). The utilisation of spiral CT scans (SCTS) for quantifying muscle volumes and weights, using automatic image analysis procedures has also been shown to be very accurate in sheep (Navajas et al., 2006). Although the limiting size of the CT gantry prevents CT scanning of live beef cattle, beef primal joints are small enough to be scanned. Hence, SCTS could be used to quantify beef carcass composition, and provide valuable information for breeding programmes including composition faster than by anatomical dissection. The objective of this study was to develop a CT image analysis procedure to assess fat, muscle and bone weights of beef carcasses and to evaluate its accuracy.
Recent CAP reforms for the sheep sector are likely to partially shift the emphasis from intensive to lower input, ‘easy care’ husbandry systems. The ability of sheep to lamb unaided would be crucial to the success of these systems. Dystocia is the most common cause of parturient lamb mortality, and pelvic dimensions are important factors in causing dystocia in ewes (Quinlivan, 1971). This study uses pelvimetry, based on both external and in vivo measures obtained by computed tomography (CT), to undertake preliminary studies on the associations among the incidence of dystocia, and other factors including maternal behaviour score (MBS) (Lambe et al., 2001).
Good bone quality in breeding ewes is important for the mineralisation of foetal skeletons and to sustain maternal dentition, as tooth loss is the main reason for culling sheep in the UK. Among other functions, bone is a storage depot for calcium and other key minerals that are mobilised to meet major demands such as during lactation. As other studies in humans and poultry have shown, there is substantial genetic variation (h2 between 0.5 and 0.8) for bone properties, suggesting a similar situation in ewes. These properties, e.g. bone density, are key to successful production and nurturing of healthy lambs, which can be used in selective breeding strategies to extend breeding ewes’ productive lives. CT has been shown to be a useful method of assessing bone properties in sheep (Rubin et al., 2001). This study quantifies the main bone types in Scottish Blackface ewes and investigates environmental factors affecting bone quality.
The amount and distribution of different body tissues changes as lambs grow and mature. Ratios of muscle to bone and of fat to muscle increase with growth post-weaning, as does muscularity (Jones et al., 2002), with the rate of change differing between breeds. Growth patterns have also been found to affect carcass composition (e.g. Thatcher and Gaunt, 1992). This preliminary study investigated the effects of growth rate on in vivo body composition and shape measurements and their relationships, in two contrasting breeds of lambs.
The development of genetic markers and their application to farm animals has progressed rapidly, opening new prospects for identifying chromosomal regions that control quantitative traits (quantitative trait loci or QTL). However, there is less activity in QTL identification in sheep than in other livestock species. Surprisingly few QTL have been published for traits of direct relevance to sheep meat production, apart from studies of individual major genes such as the callipyge locus (Freking et al, 2002). This suggests there may be more QTL effects still to be found in sheep. Hence, this study aims to identify QTL for carcass composition and meat quality traits. This will provide a basis for targeting genomic regions to verify QTL in independent sheep populations.
Selection objectives in sheep breeding are changing as the nature of the pressures upon the sheep industry change. Sheep breeders particularly need to address product quality traits, as these will determine consumer acceptance of lamb. Critical traits determining product quality are carcass composition and meat quality. New measurement technology, such as Computer Tomography (CT), offers the potential for more accurate measurement of carcass traits in the live animal and consequently improved genetic gains. On the other hand, meat quality traits pose particular problems for improvement, as measurement is generally restricted to the slaughtered animal. The present study was designed to investigate carcass composition (as measured by CT) and meat quality traits, determine the inheritance of these traits, relationships between them, and investigate the prediction of meat quality traits from CT measurements. At a later stage, these data will form the basis for QTL studies for carcass and meat quality traits.
A new approach is proposed to analyze Bremsstrahlung X-rays that are emitted from laser-produced plasmas (LPP) and are measured by a stack type spectrometer. This new method is based on a spectral tomographic reconstruction concept with the variational principle for optimization, without referring to the electron energy distribution of a plasma. This approach is applied to the analysis of some experimental data obtained at a few major laser facilities to demonstrate the applicability of the method. Slope temperatures of X-rays from LPP are determined with a two-temperature model, showing different spectral characteristics of X-rays depending on laser properties used in the experiments.
Nutritional impact of the Tick front-of-pack labelling programme was evaluated by investigating nutrient changes to the purchased food supply and the nutritional quality of Tick v. non-Tick products. Factors influencing manufacturers’ decisions to develop and license Tick products were also explored.
Observational, cross-sectional and change over time data.
New Zealand food supply, 2011–2013.
Forty-five newly licensed Tick products from five food categories were analysed: Edible Oil Spreads, Yoghurt & Dairy Desserts, Frozen Desserts, Ready Meals and Processed Poultry. Four manufacturers of these products were interviewed.
Eligible products (31 % of all Tick products in these categories) removed 4·1 million megajoules of energy, 156·0 tonnes of saturated fat, 15·4 tonnes of trans-fat and 4·0 tonnes of sodium from food products sold in New Zealand over three years. In each food category, these Tick products were, on average, 14–76 % lower in energy, saturated fat, trans-fat and sodium than non-Tick products, indicating healthier options. Participating manufacturers reported that international market trends and consumer demand for tasty, healthy foods primarily influenced Tick product development and sales. Tick was used as part of their marketing strategy as it was perceived as a credible, well-recognised logo for New Zealand consumers. Tick was cited as the primary initiative encouraging saturated fat reduction.
The Tick Programme is continuing to encourage manufacturers to make meaningful improvements to the nutritional quality of the New Zealand food supply. Over time, these changes are likely to influence population nutrient intakes and reduce CVD risk factors.
This paper describes a preliminary series of observations of the Sun made at a frequency of 80 MHz with the 3 km radioheliograph of the Culgoora Observatory. The instrument records, at one-second intervals, pictures of the solar image in the form of 60 (E-W) × 48 (N-S) points, each separated in angle by half the Rayleigh limit (2’ arc in the zenith). At the time of the present observations the instrument was incomplete in three main respects : (a) the facilities for recording opposite senses of circular polarization were not available; (b) the automatic image compensation for zenith-angle foreshortening was not available—hence the optical disk of the Sun appears elliptical; and (c) the phase and amplitude calibration procedures had not been fully established, resulting in a higher sidelobe level than that specified in the design—the effects are sometimes evident in the pictures as spoke-like brightenings.
During the Skylab period from June 1973 to January 1974 approximately 1500 type III metre-wave radio bursts or burst groups were reported (Solar Geophysical Data Prompt Reports). The longitudinal distribution of these type III bursts closely resembles that of sunspots and of the coronal transients observed above 2 R⊙ by the white-light coronagraph on Skylab. White light ejection transients appear as large loop or blob-like structures which carry material outward from the Sun and rearrange the corona. In front of the main, bright structures there are weak enhancements of brightness, termed forerunners (Jackson and Hildner 1978; Jackson 1978). In this paper we enquire into whether or not type III bursts are in any way related to the onset of solar mass ejections indicated by coronal transients.
On 17 June 1968 we observed a flare event with the 80 MHz Culgoora radioheliograph consisting of a sequence of two type II bursts followed by enhanced emission possibly of type IV. In this paper we shall attempt to summarize some ofthe profuse data collected by the radioheliograph during this event and relate it to data from the radiospectrograph and Hα films of the associated flare (the Hα films were kindly made available by the Division of Physics, CSIRO).