25 research outputs found

    Digestion of timothy silage and hay in reindeer

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    Leafy timothy (Phleum pratense) silage (S), silage mixed with molasses (SM) and hay (H) were fed to nine male reindeer (Rangifer tarandus tarandus) calves in winter to investigate rumen function and digestion. Three calves were given S with 18.5% dry matter (DM), three were given SM (21.9% DM) and three were given H (85.0% DM). The content of water soluble carbohydrates (in % of DM) was 8.2% in S, 16.0% in SM and 8.5% in H. Median (range) daily DM food intake per kg BM was 12.9 (9-2-14.4) g in calves fed S, 19.0 (19-0-21.9) g in calves fed SM and 21.0 (19.2¬21.1) g in calves fed H. In vivo digestion of S and SM DM ranged from 78.5-83.1% compared to only 69-9-72.9% in calves fed H. In vitro DM digestion (IVDMD) of cellulose (median) incubated for 48 hours in rumen fluid was, however, significantly (F = 0.05) lower in calves fed S (24.4%) compared to calves fed SM (42.2%). Median IVDMD of cellulose (48 hours) in calves fed H was 36.4%. Total concentration of VFA (range) in the rumen fluid from reindeer fed H (99.7-113.6 mM) and was significantly (P<0.05) higher compared to animals fed S (57.7-85.9 mM) or SM (51.4-72.0 mM). Likewise, the pH of the rumen fluid (range) was significantly (P<0.05) lower in reindeer fed H (6.40-6.78) compared to animals fed S (6.97-7.30) or SM (6.79-7.27). Based on this study it is concluded that leafy timothy preserved as hay seems to be more suitable as emergency feed compared to silage. Supplementation of molasses to silage seems to stimulate food intake and ruminal cellulose digestion in reindeer. The lower intake of S compared to SM or H by reindeer may be explained by ruminal energy deficiency

    The impact of thermal seasonality on terrestrial endotherm food web dynamics: a revision of the Exploitation Ecosystem Hypothesis

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    Many terrestrial endotherm food webs constitute three trophic level cascades. Others have two trophic level dynamics (food limited herbivores; plants adapted to tackle intense herbivory) or one trophic level dynamic (herbivorous endotherms absent, thus plants compete for the few places where they can survive and grow). According to the Exploitation Ecosystems Hypothesis (EEH), these contrasting dynamics are consequences of differences in primary productivity. The productivity thresholds for changing food web dynamics were assumed to be global constants. We challenged this assumption and found that several model parameters are sensitive to the contrast between persistently warm and seasonally cold climates. In persistently warm environments, three trophic level dynamics can be expected to prevail almost everywhere, save the most extreme deserts. We revised EEH accordingly and tested it by compiling direct evidence of three and two trophic level dynamics and by studying the global distribution of felids. In seasonally cold environments, we found evidence for three trophic level dynamics only in productive ecosystems, while evidence for two trophic level dynamics appeared in ecosystems with low primary productivity. In persistently warm environments, we found evidence for three trophic level dynamics in all types of ecosystems. The distribution of felids corroborated these results. The empirical evidence thus indicates that two trophic level dynamics, as defined by EEH, are restricted to seasonally cold biomes with low primary productivity, such as the artic-alpine tundra and the temperate steppe

    Tales from the outer limits: Archaeological geophysical prospection in lowland peat environments in the British Isles

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    In order to systematically investigate the potential of conventional near surface geophysical techniques to locate waterlogged archaeological targets in peatlands, the authors applied four conventional geophysical methods – earth resistance, ground‐penetrating radar (GPR), magnetic gradiometry and frequency domain electromagnetics (FDEM) – to four lowland peat archaeological test sites in Great Britain. In this article we demonstrate that a Neolithic trackway was identified in the GPR data in Somerset, with likely ‘proxy’ detections of chemical changes showing up in both electrical and magnetic surveys. This was determined by a coring programme and inductively coupled plasma optical emission spectrometry (ICP‐OES) multi‐element analysis of peat samples to determine the relative concentrations of geophysically relevant chemical elements. Though no Bronze Age timbers were detected at Flag Fen, a post‐Bronze Age agricultural landscape was identified in both the GPR and gradiometer surveys. We conclude that GPR has the greatest potential for archaeological geophysical prospection in peatland environments, but that electrical and magnetic methods can usefully be employed as secondary sources of information and should not be discounted from future research. Further, this article argues that better understandings must be developed of the impacts of geochemistry on geophysical data if we are going to realistically pursue ‘whole landscape’ surveys

    Norwegian Sami differs significantly from other Norwegians according to their HLA profile

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    This study reports extensive genomic data for both human leukocyte antigen (HLA) class I and II loci in Norwegian Sami, a native population living in the northwest of Europe. The Sami have a distinct culture and their own languages, which belong to the Uralic linguistic family. Norwegian Sami (n = 200) were typed at the DNA level for the HLA-A, -C, -B, -DRB1 and -DQB1 loci, and compared with a non- Sami Norwegian population (n = 576). The two populations exhibited some common genetic features but also differed significantly at all HLA loci. The most significantly deviating allele frequencies were an increase of HLA-A*03, -B*27, -DRB1*08 and -DQB1*04 and a decrease of HLA-A*01, C*01, -DRB1*04 and -DQB1*02 among Sami compared with non-Sami Norwegians. The Sami showed no deviation from Hardy–Weinberg equilibrium. The hypothesis of selective neutrality was rejected at all loci except for the A- and C- loci for the Sami. HLA haplotype frequencies also differed between the two populations. The most common extended HLA haplotypes were A*02-B*27-C*01-DR*08-DQB1*04 in the Sami and A*01-B*08-C*07-DR*03- DQB1*02 in the other Norwegians. Genetic distance analyses indicated that theNorwegian Sami were highly differentiated from other Europeans and were most closely related to Finns whose language also belongs to the Uralic linguistic family. In conclusion, the Norwegian Sami and the non-Sami Norwegians were significantly different at all HLA loci. Our results can be explained by the fact that the two populations have different origins and that the Sami population has remained smaller and more isolated than its neighbors

    Recommendations for the safety of people and instruments in ground-penetrating radar and near-surface geophysical prospecting

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    This book offers an in-depth overview on the risks associated to Ground-Penetrating Radar (GPR) and Near-Surface Geophysical Prospecting, providing the reader with practical recommendations for the safety of people and instruments. The book stems out from the COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" . It also benefited from the significant contribution of renowned experts not involved in the Action. Among the main topics dealt with in the book, the reader will find: general recommendations for a safe prospecting and minimal safety equipment to be brought in the field; specific advice for experimental campaigns carried out in challenging environmental situations; appropriate precautions related to specific kinds of GPR applications; dangers associated to electromagnetic emissions and European regulations for GPR manufacturers and end-users. The book includes a short medical first aid guide as well, which is specifically conceived for near-surface geophysical prospecting. Suggestions for correct use and safe transport of the equipment are also provided

    Recommendations for the safety of people and instruments in ground-penetrating radar and near-surface geophysical prospecting

    No full text
    This book offers an in-depth overview on the risks associated to Ground-Penetrating Radar (GPR) and Near-Surface Geophysical Prospecting, providing the reader with practical recommendations for the safety of people and instruments. The book stems out from the COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" . It also benefited from the significant contribution of renowned experts not involved in the Action. Among the main topics dealt with in the book, the reader will find: general recommendations for a safe prospecting and minimal safety equipment to be brought in the field; specific advice for experimental campaigns carried out in challenging environmental situations; appropriate precautions related to specific kinds of GPR applications; dangers associated to electromagnetic emissions and European regulations for GPR manufacturers and end-users. The book includes a short medical first aid guide as well, which is specifically conceived for near-surface geophysical prospecting. Suggestions for correct use and safe transport of the equipment are also provided

    The impact of thermal seasonality on terrestrial endotherm food web dynamics:a revision of the Exploitation Ecosystem Hypothesis

    Get PDF
    Abstract Many terrestrial endotherm food webs constitute three trophic level cascades. Others have two trophic level dynamics (food limited herbivores; plants adapted to tackle intense herbivory) or one trophic level dynamic (herbivorous endotherms absent, thus plants compete for the few places where they can survive and grow). According to the Exploitation Ecosystems Hypothesis (EEH), these contrasting dynamics are consequences of differences in primary productivity. The productivity thresholds for changing food web dynamics were assumed to be global constants. We challenged this assumption and found that several model parameters are sensitive to the contrast between persistently warm and seasonally cold climates. In persistently warm environments, three trophic level dynamics can be expected to prevail almost everywhere, save the most extreme deserts. We revised EEH accordingly and tested it by compiling direct evidence of three and two trophic level dynamics and by studying the global distribution of felids. In seasonally cold environments, we found evidence for three trophic level dynamics only in productive ecosystems, while evidence for two trophic level dynamics appeared in ecosystems with low primary productivity. In persistently warm environments, we found evidence for three trophic level dynamics in all types of ecosystems. The distribution of felids corroborated these results. The empirical evidence thus indicates that two trophic level dynamics, as defined by EEH, are restricted to seasonally cold biomes with low primary productivity, such as the artic–alpine tundra and the temperate steppe
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