798 research outputs found
Pitcairn before the mutineers: Revisiting the isolation of a Polynesian Island
The myth of Pitcairn, building on the destiny of the Bounty mutineers, focuses on the recent history of this island as the epitome of marginality and isolation. Human occupation of the island, however, occurred long before the Bounty settlement, and Pitcairn provides a fascinating example of Polynesian sustainability that is little known to the general public. Located at the eastern fringe of Central Eastern Polynesia, the Pitcairn group includes the volcanic island of Pitcairn (4.5 square kilometres), the elevated limestone island of Henderson (37.2 square kilometres) and the two small atolls of Oeno and Ducie (Figure 2.1). Situated approximately 400 kilometres east of the Gambier Islands and 1,700 kilometres west of Rapa Nui/Easter Island, this island group is one of the world’s most geographically isolated
Normalized solutions to mass supercritical Schroedinger equations with negative potential
We study the existence of positive solutions with prescribed L-2-norm for the mass supercritical Schrodinger equation -delta u+lambda u - V(x)u = |u|(p-2)u u is an element of H-1(R-N), lambda is an element of R, where V >= 0, N >= 1 and p is an element of(2+4/N, 2*), 2*: = 2N/N-2 if N >= 3 and 2* : = +infinity if N = 1,2. We treat two cases. Firstly, under an explicit smallness assumption on V and no condition on the mass, we prove the existence of a mountain pass solution at positive energy level, and we exclude the existence of solutions with negative energy. Secondly, requiring that the mass is smaller than some explicit bound, depending on V, and that V is not too small in a suitable sense, we find two solutions: a local minimizer with negative energy, and a mountain pass solution with positive energy. Moreover, a nonexistence result is proved
Intake by Lactating Goats Browsing on Mediterranean Shrubland
In Mediterranean regions goat feeding systems are mainly based on shrubland that contain a wide variety of species. There are only a few equations for predicting feed intake of stall-fed goats (Luo et al., 2004). The objective of this study was to develop a model for predicting the intake of lactating goats browsing on Mediterranean shrubland
Effect of different pastures on CLA content in milk and sheep cheese
It is known that milk composition included conjugated linoleic acid (CLA) is affected by animal feeding system (Cabiddu et al., 2001). In Sardinia dairy sheep feeding is mainly based on pastures. Most of them are characterised by self-regenerating species, like annual ryegrass (Lolium rigidum Gaudin) and burr medic (Medicago polymorpha L.). Non conventional species belonging to the Compositae family such as (Chrysanthemum coronarium L.) seem interesting for sheep feeding when other herbages decrease in quality (late spring- early summer). It was observed that C. coronarium establishes rapidly, can be grazed early in the growing season and persist where other pasture species
may disappear; for these reasons it can be considered a valuable source of food. Moreover a preliminary
study with dairy sheep fed fresh forage of C. coronarium showed relatively high levels of CLA in milk
(Molle G. pers. com.) The aim of the present work was to study the influence of different pastures on milk composition, with particular reference to CLA and its precursors
Grassland resources for extensive farming systems in marginal lands: major drivers and future scenarios
Evidence for membrane affinity of the C-terminal domain of bovine milk PP3 component
AbstractComponent PP3 is a phosphoglycoprotein isolated from bovine milk with unknown biological function, which displays in its C-terminal region a basic amphipathic α-helix, a feature often involved in membrane association. According to that, the behaviour of PP3 and of a synthetic peptide from the C-terminal domain (residues 113–135) was investigated in lipid environment. Conductance measurements indicated that the peptide was able to associate and form channels in planar lipid bilayers composed of neutral or charged phospholipids. Electrostatic interactions seemed to promote voltage-dependant channel formation but this was not absolutely required since the pore-forming ability of the 113–135 C-terminal peptide was also detected with the zwitterionic lipid bilayer. Additionally, a spectroscopic study using circular dichroism argues that the peptide adopts an α-helical conformation in interaction with neutral or charged micelles. Thus, the conducting aggregates in bilayers might be composed of a bundle of peptides in helical conformation. Besides, similar conductance measurements performed with the whole PP3 protein did not induce any channel fluctuations. However, with the latter, an early breakdown of the bilayers occurred, a finding that can be tentatively explained by a massive incorporation of PP3. In the light of the present results, it could be inferred that PP3 membrane attachment may be achieved by oligomerization of the C-terminal amphipathic helical region
Compilation of a Database of Research Information on Legume Based Grazing Systems; a Part of the Leggraze Research Project
The establishment of a publicly accessible web-resident database of published and current European research on agronomy, animal production and environmental impact of legume based grazing systems is reported. This database facilitates the sharing of information among the partners of the Low input animal production based on forage legumes for grazing systems (Leggraze), a research project funded by the UE (QL K5 CT-2001-02328). It also forms an important tool for transferring the results of the project to the wider research community and to end users in the agricultural sector and to policy makers at national and community level
A Systems Approach to Assessing the Viability of Grazing Legume Systems Across Europe
Forage legumes are important in grassland farming throughout much of the world because of their ability to fix atmospheric nitrogen, and hence they are expected to play an increasingly prominent role in low- input grazing farming systems in Europe. Nevertheless, the socio-economic impact of the adoption of the new legume based grazing technologies have been poorly researched (Rochon et al., 2004). Thus a methodology has been developed to:
* Assess the on-farm costs and benefits of including different legume crops for animal production;* Determine the types of management systems and environmental conditions under which forage legumes may play a major part as grazing crops in production systems in Europe;* and Determine the wider social, economic and environmental implication of widespread adoption of the new technologies
A review on the effects of part-time grazing herbaceous pastures on feeding behaviour and intake of cattle, sheep and horses
Part-time grazing (PTG) is the grazing technique based on the time-restricted access to pasture of farmed herbivores, usually supplemented indoors. This review evaluates the effects of the duration of access to pasture on the functional responses of grazing time and herbage intake rate in cattle, sheep and horses and the implications of these responses on diet selection, diet digestibility, energy expenditure, animal welfare, the performance of ruminants and the quality of their products (milk and meat).
Ruminants with restricted access time to pasture display compensatory behaviour through increased intake rate, achieving similar levels of intake and performance compared with 24 h-grazing ruminants, particularly if access time is in the range 6-8 h/d. This can depend on the reduction of locomotion energy expenditure, and, sometimes, on the selection of a better quality diet than that on offer. Nevertheless, due to lower ingestive fibre trituration, fibre digestibility could be reduced, particularly with access time <4 h/d. Moreover, milk content of FA regarded as beneficial for consumers' health, such as n-3 PUFA and rumenic acid, is usually higher in PTG than stall-fed ruminants, with a minimum access to grass pasture of 6 h/d in cows supplemented with total mixed rations or 4 h/d in sheep supplemented with concentrate and hay. Timing the grazing session of ruminants in the afternoon and evening hours is a good strategy to match pasture quality and animal attitude to forage intensively and efficiently, favouring intake, performance and produce quality.
Horses show on average lower intake rates scaled to metabolic weight than ruminants, probably due to their lower energy requirements but also for the need to spend part of the time outdoor performing physical activity and social behavior. Therefore, they probably need longer access time than ruminants. However, access should be time restricted or avoided during periods of the year and day hours (from midday to evening) when herbage content of non structural carbohydrates (sum of starch and water soluble carbohydrates) is high (> 15 % DM) since it can be conducive to equine metabolic syndrome and laminitis.
In general, PTG can improve ruminant and horse welfare as compared with stall-feeding with reference to appropriate behavior and freedom from some pathologies, although further research is needed to quantify these effects on a wider range of animal species and welfare indicators
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