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Nutritional Consequences (nutritional + consequence)
Selected AbstractsEthanol Consumption Alters Electroretinograms and Depletes Neural Tissues of Docosahexaenoic Acid in Rhesus Monkeys: Nutritional Consequences of a Low n-3 Fatty Acid DietALCOHOLISM, Issue 12 2001Robert J. Pawlosky Background: Alcohol amblyopia is a rare neuropathy characterized by the development of blurred vision and a reduction in visual acuity. Further diagnostic details of this condition have shown abnormalities in the electroretinogram (ERG) that include an increase in implicit times in the a- and b-waves and a depression of b-wave amplitude. Methods: Periodically, the ERGs and the fatty acyl composition of nervous tissue were analyzed from alcohol-consuming rhesus monkeys (Macaca mulatta) (mean consumption 2.6 g kg/day over a 5-year period) and controls that were maintained on a nutritionally sufficient diet that had low, yet adequate, amounts of linoleic acid but very low ,-linolenic acid. Results: Animals consuming alcohol had increased a- and b-wave implicit times and decreased b-wave amplitudes in their electroretinograms compared with those of the dietary control group at 2.5 and 5 years. The fatty acyl composition of brain specimens obtained by surgical biopsy at baseline, 2.5 years, and 5 years demonstrated that docosahexaenoic acid (DHA) had decreased in both groups of animals compared with baseline values. In the brains of the alcohol-treated animals, DHA was even further decreased (2.5 years: ,20%; 5 years: ,33%) compared with the diet controls. In the retinas of the alcohol-consuming animals at 5 years, there was a similar decrease in DHA (-35%) compared with controls. Generally, the n-6 fatty acid, docosapentaenoic acid (DPAn-6) increased in these tissues, apparently compensating for the loss of DHA. Conclusions: A reciprocal change in the DHA/DPAn-6 ratio is known to be associated with abnormal electroretinograms in a number of species. Thus, a marginal intake of n-3 fatty acids in some alcohol abusers may, in part, be responsible for the biochemical changes that underlie the diminished retinal function associated with the visual abnormalities observed in alcohol-amblyopic patients. [source] Nutritional consequences of a change in diet from native to agricultural fruits for the Samoan fruit batECOGRAPHY, Issue 4 2000Suzanne L. Nelson The Samoan fruit bat Pteropus samoensis Peak, an endemic flying fox that inhabits the Samoan archipelago, prefers to forage on native fruit species. This species has recently been subjected to extreme population threats including hunting and severe storms, as well as large-scale habitat degradation. If habitat destruction continues at its present rate, P. samoensis may be forced to forage more within an agricultural matrix. In this study, we analyzed sixteen species of native fruits and four species of agricultural fruits for five organic components and eight minerals to test whether native fruits provided a higher quality diet or more varied diet than agricultural fruits. Within native fruits, we also focused on four species of figs, because these fruits are often considered an important food item for tropical frugivores. Overall, native fruits provided more variation and had higher average values for several nutrients than agricultural fruits. Native fruits were especially high in biologically important minerals (calcium, iron, and sodium), and provided up to 5 times more calcium, 10.5 times more iron, and 8 times more sodium than agricultural fruits. Figs were found to be an especially rich source of many nutrients, particularly for calcium. Thus. P. samoensis. a sequential specialist, may be better able to adjust its diet to obtain higher levels of minerals when consuming a variety of native fruits than when restricted to the consumption of only agricultural fruits. These findings suggest a need to preserve native habitat and to create parks to sustain the long term health and viability of P. samoensis. [source] Does the pelleting process affect the nutritive value of a pre-starter diet for suckling piglets?JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2010Ex vivo studies on mineral absorption Abstract BACKGROUND: The effects of pelleting on the extent of the Maillard reaction (MR) and on calcium, magnesium and zinc solubility and absorption were analysed in a conventional pre-starter diet for suckling piglets. Development was tested measuring colour, absorbance (280/420 nm), fluorescence, residual free lysine, furosine, hydroxymethylfurfural (HMF) and furfural contents before and after pelleting. Fluorescence, absorbance and mineral solubility were also measured after in vitro digestion of diets. The effects on mineral absorption were tested using Caco-2 cells. RESULTS: MR indexes confirmed the development of the reaction during the pelleting of this particular diet compared with the meal diet. The CIE-Lab colour parameters showed a decrease in luminosity (L*) and progress of the colour to the red zone (a*) in the pelleted diet. A 36% decrease in free lysine content was observed. Significant correlations were observed between fluorescence intensity and furosine levels, HMF and furfural. The pelleting process did not modify calcium and magnesium solubility after in vitro digestion, but soluble zinc increased. The efficiency of calcium and zinc transport across Caco-2 cell monolayers was greater in the pelleted diet. CONCLUSIONS: Evidence of MR development is shown, resulting in various nutritional consequences. Optimisation of pelleting could result in a better formulation of diets for feedstuffs. Copyright © 2010 Society of Chemical Industry [source] Orchid mycorrhiza: implications of a mycophagous life styleOIKOS, Issue 3 2009Hanne N. Rasmussen Orchid mycorrhiza probably affects about 25,000 plant species and thus roughly one tenth of all higher plants. Histologically, this symbiosis resembles other kinds of endomycorrhiza, the fungal hyphae growing within living plant cells. Considerable evidence, however, suggests that it is not a two-way exchange relationship and thus not potentially mutualistic, such as the wide-spread endomycorrhiza between plants and Glomalean fungi, known as arbuscular mycorrhiza. During the achlorophyllous seedling stage orchids are obligately dependent on the fungi; some species remain so through life, while others establish photosynthesis but to varying degrees remain facultatively dependent of /responsive to fungal infection as adults. None of the fungi involved are so far known to depend on the symbiosis with orchids. Transfer of organic carbon compounds from hyphae to the orchid has been demonstrated repeatedly, but it is not clear to what extent this takes place during a biotrophic phase while the intracellular hyphae remain intact, or during the subsequent extensive degradation of the hyphal coils. The advantage of viewing orchid mycorrhiza basically as a unilateral mycophagous relationship, in spite of hypothetical beneficial spin-offs to the mycobiont, is that it provides a conceptual framework similar to that of other parasitic or fungivore relationships; mechanisms known in such relationships could be searched for in future studies of the orchid,fungus symbiosis. These could include mechanisms for recognition, attraction and selection of fungi, physiological regulation of internal hyphal growth, breakdown, and material transfer, nutritional consequences of the plant's preference(s) and trophic changes, fungal avoidance mechanisms, and consequences at population and ecosystem levels. A whole range of possible life strategies becomes apparent that could support divergent evolution and lead to the proliferation of species that has indeed occurred in the orchid family. We outline some of the possible physiological mechanisms and ecological implications of this approach. [source] Defense mechanisms against grazing: a study of trypsin inhibitor responses to simulated grazing in the sedge Carex bigelowiiOIKOS, Issue 9 2007Åsa Lindgren Trypsin inhibitors have been suggested to constitute an inducible defense in the sedge Carex bigelowii, and some former studies suggest that this might be a cause for the cyclic population dynamics in many alpine and arctic small mammals, for example lemmings (Lemmus lemmus). We investigated this further by using a method of simulated grazing (clipping) at different intensities, in three different habitats with varying resource availability, with different harvest times (hours after clipping), and two different stages of ramets (reproductive/vegetative) in a study from the Swedish mountain range. Our results do not indicate that C. bigelowii has an inducible defense constituted by an increase in trypsin inhibitor activity (TIA), but rather that the amount of soluble plant proteins (SPP) is lowered in wounded plants. The responses were somewhat different in the three habitats, with ramets growing in the marsh showing the highest ratio of TIA to SPP, due to low amounts of SPP. We did not find any significant effects of harvest time, or of the stage of the ramet that could support the hypothesis of an inducible defense. To conclude, we could not find any evidence for an inducible defense consisting of trypsin inhibitors in Carex bigelowii ramets, but we did find variations in the amount of SPP that may have nutritional consequences for herbivores. [source] | ||||||||||