Colonies of up to 30 cats, Felis catus, which were partially dependent upon man for direct provis... more Colonies of up to 30 cats, Felis catus, which were partially dependent upon man for direct provisioning with food, were recorded on 82% of 775 English farms. They lived at a mean density of 6.3 per km2. Members of one such colony were observed intermittently from 1978-81. These ...
High-performance liquid chromatography (HPLC)-UV and HPLC-Mass Spectrometry (MS) methods were dev... more High-performance liquid chromatography (HPLC)-UV and HPLC-Mass Spectrometry (MS) methods were developed for the quantitative analysis of the family of Hoodia gordonii steroid glycosides with appetite suppressing properties in dried plant material, in purified and enriched extracts and in various prototype food-products fortified with H. gordonii extracts. For solid materials, e.g. dried plants or for non-fatty foods, extraction of the steroid glycosides is performed using methanol. For products where the steroid glycosides are present in an oil matrix, direct injection of the oil after dilution in tetrahydrofuran is applied. The HPLC separation is performed on an octyl-modified reversed-phase column in the gradient mode with UV detection at lambda = 220 nm. Quantification is performed against an external calibration line prepared using either one of the pure steroid glycosides or geranyl-tiglate. Short- and long-term repeatabilities of the methods are better than 3 and 6%, respectively. Recoveries are better than 85%, even in the analysis of the least abundant steroid glycosides in a complex yoghurt drink. Linearity is better than 3-4 orders of magnitude and the detection limits are below approximately 2 microg g(-1) for the individual steroid glycosides in dried plant material and food products. HPLC-MS is used to confirm that the steroid glycosides contain the characteristic steroid core, the carbohydrate chain and the tigloyl group.
Introduction - mammals and behaviour birth and infancy - beginnings and becomings food and water ... more Introduction - mammals and behaviour birth and infancy - beginnings and becomings food and water - the bare necessities strategies for survival - outwitting the enemy social life - bonds and boundaries communication - signalling and sensing reproduction - closing the cycle.
Wild Ways brings together all the latest studies of the behaviour of southern Africa?s rich and a... more Wild Ways brings together all the latest studies of the behaviour of southern Africa?s rich and accessible mammal fauna, describing not only what mammals do, but also the often surprising reasons why they do it, and covers species as diverse as fruit bats, pangolins, lions, rats and whales. Well-established as an invaluable resource for visitors to parks and reserves, hikers, hunters, farmers and outdoor enthusiasts, this classic guide has now been thoroughly updated and revised, has a fresh, lively design, and is packed with new and engrossing detail.
The orthodox view of mammalian chemical communication is that individuals exchange information wi... more The orthodox view of mammalian chemical communication is that individuals exchange information with members of their own species, but there is now a growing body of evidence that carnivores also send messages to members of different species. A camera trapping study in northern Botswana captured video of 21 species of carnivore, of which 18 scent marked a total of 105 times. Seventeen marks countermarked scent from the same species, and 24 marks countermarked scent from a different species. Of the 39 species of carnivore in southern Africa, 24 are involved in some kind of interspecific scent marking, and smaller webs of interspecific scent marking are found among carnivores in Europe, Australia, north and central America, and the Himalayas. Interspecific scent communication has been missed in the past due to an almost exclusive focus on single-species studies, and because the tool that is essential to study it; camera trapping, has come into widespread use only in the past decade. Now we know that interspecific scent marking is common and widespread, we need to take a closer look at it to understand its role in carnivore guild ecology.
ABSTRACT A sample inlet, based on the static solvent effect has been designed and constructed. Th... more ABSTRACT A sample inlet, based on the static solvent effect has been designed and constructed. The inlet can handle samples up to 20 μl which allows for the detection, using an F. I. D., of constituents in the parts per billion range. The reproducibility of the inlet in terms of peak percentage area is around 1% relative standard deviation over a range of chemical types.
Colonies of up to 30 cats, Felis catus, which were partially dependent upon man for direct provis... more Colonies of up to 30 cats, Felis catus, which were partially dependent upon man for direct provisioning with food, were recorded on 82% of 775 English farms. They lived at a mean density of 6.3 per km2. Members of one such colony were observed intermittently from 1978-81. These ...
High-performance liquid chromatography (HPLC)-UV and HPLC-Mass Spectrometry (MS) methods were dev... more High-performance liquid chromatography (HPLC)-UV and HPLC-Mass Spectrometry (MS) methods were developed for the quantitative analysis of the family of Hoodia gordonii steroid glycosides with appetite suppressing properties in dried plant material, in purified and enriched extracts and in various prototype food-products fortified with H. gordonii extracts. For solid materials, e.g. dried plants or for non-fatty foods, extraction of the steroid glycosides is performed using methanol. For products where the steroid glycosides are present in an oil matrix, direct injection of the oil after dilution in tetrahydrofuran is applied. The HPLC separation is performed on an octyl-modified reversed-phase column in the gradient mode with UV detection at lambda = 220 nm. Quantification is performed against an external calibration line prepared using either one of the pure steroid glycosides or geranyl-tiglate. Short- and long-term repeatabilities of the methods are better than 3 and 6%, respectively. Recoveries are better than 85%, even in the analysis of the least abundant steroid glycosides in a complex yoghurt drink. Linearity is better than 3-4 orders of magnitude and the detection limits are below approximately 2 microg g(-1) for the individual steroid glycosides in dried plant material and food products. HPLC-MS is used to confirm that the steroid glycosides contain the characteristic steroid core, the carbohydrate chain and the tigloyl group.
Introduction - mammals and behaviour birth and infancy - beginnings and becomings food and water ... more Introduction - mammals and behaviour birth and infancy - beginnings and becomings food and water - the bare necessities strategies for survival - outwitting the enemy social life - bonds and boundaries communication - signalling and sensing reproduction - closing the cycle.
Wild Ways brings together all the latest studies of the behaviour of southern Africa?s rich and a... more Wild Ways brings together all the latest studies of the behaviour of southern Africa?s rich and accessible mammal fauna, describing not only what mammals do, but also the often surprising reasons why they do it, and covers species as diverse as fruit bats, pangolins, lions, rats and whales. Well-established as an invaluable resource for visitors to parks and reserves, hikers, hunters, farmers and outdoor enthusiasts, this classic guide has now been thoroughly updated and revised, has a fresh, lively design, and is packed with new and engrossing detail.
The orthodox view of mammalian chemical communication is that individuals exchange information wi... more The orthodox view of mammalian chemical communication is that individuals exchange information with members of their own species, but there is now a growing body of evidence that carnivores also send messages to members of different species. A camera trapping study in northern Botswana captured video of 21 species of carnivore, of which 18 scent marked a total of 105 times. Seventeen marks countermarked scent from the same species, and 24 marks countermarked scent from a different species. Of the 39 species of carnivore in southern Africa, 24 are involved in some kind of interspecific scent marking, and smaller webs of interspecific scent marking are found among carnivores in Europe, Australia, north and central America, and the Himalayas. Interspecific scent communication has been missed in the past due to an almost exclusive focus on single-species studies, and because the tool that is essential to study it; camera trapping, has come into widespread use only in the past decade. Now we know that interspecific scent marking is common and widespread, we need to take a closer look at it to understand its role in carnivore guild ecology.
ABSTRACT A sample inlet, based on the static solvent effect has been designed and constructed. Th... more ABSTRACT A sample inlet, based on the static solvent effect has been designed and constructed. The inlet can handle samples up to 20 μl which allows for the detection, using an F. I. D., of constituents in the parts per billion range. The reproducibility of the inlet in terms of peak percentage area is around 1% relative standard deviation over a range of chemical types.
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