916 resultados para low food secure


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Leptin is a circulating protein involved in the long-term regulation of food intake and body weight. Cholecystokinin (CCK) is released postprandially and elicits satiety signals. We investigated the interaction between leptin and CCK-8 in the short-term regulation of food intake induced by 24-hr fasting in lean mice. Leptin, injected intraperitoneally (i.p.) at low doses (4–120 μg/kg), which did not influence feeding behavior for the first 3 hr postinjection, decreased food intake dose dependently by 47–83% during the first hour when coinjected with a subthreshold dose of CCK. Such an interaction was not observed between leptin and bombesin. The food-reducing effect of leptin injected with CCK was not associated with alterations in gastric emptying or locomotor behavior. Leptin–CCK action was blocked by systemic capsaicin at a dose inducing functional ablation of sensory afferent fibers and by devazepide, a CCK-A receptor antagonist but not by the CCK-B receptor antagonist, L-365,260. The decrease in food intake which occurs 5 hr after i.p. injection of leptin alone was also blunted by devazepide. Coinjection of leptin and CCK enhanced the number of Fos-positive cells in the hypothalamic paraventricular nucleus by 60%, whereas leptin or CCK alone did not modify Fos expression. These results indicate the existence of a functional synergistic interaction between leptin and CCK leading to early suppression of food intake which involves CCK-A receptors and capsaicin-sensitive afferent fibers.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Elysia timida (Risso, 1818) colonizing the shallow waters of the Mar Menor Lagoon (Spain) exhibit a brown and a green morph. It was hypothesised that these morphs were the result of feeding preferentially on brown and green algae, respectively. E. timida and its potential food sources, Acetabularia acetabulum (Chlorophyta) and Halopteris filicina (Heterokontophyta) were collected by snorkelling during April 2010. Photosynthetic pigments were analysed by HPLC, photo-physiological parameters were estimated by PAM fluorometry and body colour was characterized by spectral reflectance. Digital photography was used to count the number and area of red spots (small red dots on the slug’s surface) on the parapodia of the 2 morphs. In the laboratory, green E. timida was fed with A. acetabulum cultured under 2 light treatments (high light, 600 µmol E m−2 s−1 and low light, 40 µmol E m−2 s−1), and digital photography was used to monitor colour alterations in E. timida. Spectral reflectance confirmed the colour differences, but both morphs showed a pigment composition similar to the green alga A. acetabulum and showed none of the pigments present in the brown alga H. filicina, neither immediately after collection of the slugs in situ, nor after the feeding experiment. A. acetabulum grown under high light intensity changed from green to brown colour and E. timida changed to brown colour when fed with high-light acclimated A. acetabulum. Thus, E. timida colour differences could not be attributed to feeding on different algae groups but was likely the result of feeding on A. acetabulum growing under different light intensities.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The task of ensuring the democratic legitimacy of the euro has been placed high on the agenda. A eurozone subcommittee in the European Parliament is one of the rare concrete proposals to secure this, creating high hopes. Due to legal and political hurdles the idea might nonetheless have minimal results, which might result in suboptimal parliamentary scrutiny of the eurozone. This Policy Brief argues that if a eurozone subcommittee is to be both meaningful and politically feasible, it should combine substantial competences with innovative decision-making.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Goose grazing on arctic tundra vegetation has shown both positive and negative effects on subsequent foraging conditions. To understand the potential of a density-dependent feedback on herbivore population size, the relation between grazing pressure and future foraging conditions is essential. We studied the effect of increasing grazing pressure of barnacle geese (Branta leucopsis) on Spitsbergen. During the establishment of a breeding colony in the period 1992-2004, the proportion of graminoids decreased in the diet of wild geese, while the percentage of mosses increased. Grazing trials with captive geese in an unexploited area showed a similar shift in diet composition. High-quality food plants were depleted within years and over years. Intake rate declined too and as consequence, metabolisable energy intake rate (MEIR) decreased rapidly with increasing grazing pressure. During three successive years of experimental grazing, MEIR decreased at all levels of grazing pressure and declined below minimal energetic requirements when grazing exceeded natural levels of grazing pressure. This suggests that foraging conditions rapidly decline with increasing grazing pressure in these low-productive habitats. The potential for density-dependent feedbacks on local population increase is discussed.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

General account of the various activities of the Food Investigation Organization during the year under review; divided into 2 parts: Report of the Board, surveying the main developments during the year; and: Report of the Director. Also includes the reports of its research stations, <1931>-57: Torry Research Station (on fish); Low Temperature Research Station (on meat, eggs, poultry, and plant tissues); and: Ditton Laboratory (on fruit and vegetbles).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Cadmium is a cumulative nephrotoxicant that is absorbed into the body from dietary sources and cigarette smoking. The levels of Cd in organs such as liver and kidney cortex increase with age because of the lack of an active biochemical process for its elimination coupled with renal reabsorption. Recent research has provided evidence linking Cd-related kidney dysfunction and decreases in bone mineral density in nonoccupationally exposed populations who showed no signs of nutritional deficiency. This challenges the previous view that the concurrent kidney and bone damage seen in Japanese itai-itai disease patients was the result of Cd toxicity in combination with nutritional deficiencies, notably, of zinc and calcium. Further, such Cd-linked bone and kidney toxicities were observed in people whose dietary Cd intakes were well within the provisional tolerable weekly intake (PTWI) set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives of 1 mug/kg body weight/day or 70 mug/day. This evidence points to the much-needed revision of the current PTWI for Cd. Also, evidence for the carcinogenic risk of chronic Cd exposure is accumulating and Cd effects on reproductive outcomes have begun to emerge.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The textures of yogurt made from ultra-high temperature (UHT) treated and conventionally treated milks at high total solids were investigated. The yogurt premixes, fortified with low-heat skim milk powder to 16%, 18%, and 20% total solids, were UHT processed at 143 degreesC for 6 s and heated at 85 degreesC for 30 min using the conventional method. The onset of gelation was delayed in the UHT-processed milk compared with conventionally heated milk. During fermentation, the viscosity of yogurt made, from UHT-treated milk at 20% total solids was close to that of yogurt made from conventionally treated milk with 16% total solids. However, after storage for greater than or equal to1 d, the yogurt made from UHT-treated milk had lower viscosity and gel strength than the yogurt made from conventionally treated milk. The solids level had no influence on yogurt culture growth.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Coccidoxenoides perminutus achieves only low levels of parasitism of its host Planococcus citri in southeast Queensland citrus. Two possible causes were investigated. Adult survival under natural conditions was assessed to determine whether providing adult food sources could enhance survival. Behavioural changes of hosts, induced by C perminutus parasitism, was also investigated to establish if parasitised P. citri move from their feeding site to seek protected shelters some distance away and are thus not accounted for in field assessments of parasitism rates. Unparasitised mealybugs placed in the field for two periods were retrieved before the effects of parasitism were manifested and parasitism rates were still low (0.3% at 5 days and 1.2% at 10 days). Levels of locomotion of P. citri exposed to C perminutus were compared with those of unexposed ones. Parasitised mealybugs, regardless of instar, undergo behavioural changes. In comparison to unparasitised controls, the mealybugs become highly active 7-14 days after exposure to wasps. All parasitised mealybugs undergo physical changes, their body becomes cylindrical, their legs go so rigid that the mealybugs become immobile, and this signifies the typical mummy appearance. All mealybugs that became mummies eventually fell from the host lemon fruit because of impaired locomotion and were caught on sticky traps that had been placed beneath the lemons. Consequently, their final site of mummification was not established. C perminutus adults provided with nectar or honey survived longer (about 5 days) in the field than those without food (about a day). Nectar from two plant species, Alpinia zerumbet and Datura candida, proved to be good sources of food for the adult wasps, and were comparable in quality to honey. The low level of parasitism achieved by C perminutus in southeast Queensland citrus thus appears to be a consequence of the short adult life and the negative effects of a harsh environment. Provision of a suitable food source (e.g., nectar) may well enhance levels of parasitism in the field. (c) 2005 Elsevier Inc. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The authors assessed the contribution of food irrigated with arsenic-contaminated water to human exposure to arsenic in Bangladesh. An intervention trial was conducted in a village in the Jessore District of Bangladesh, where irrigation water had been field-tested in March 2000 and was found to contain arsenic with concentrations ranging from 100 to 500 mu g/l. In May 2000, a random sample of 63 households was selected from the village, and I eligible person from each household was recruited to the study and randomized to an intervention or control group. The intervention group received food purchased from a village where irrigation water was found to contain 100 mu g/l arsenic. Pre- and postintervention urine samples were collected for urinary arsenic speciation assays. Preintervention, the mean urinary total arsenic concentrations were 139.25 mu g/l and 129.15 mu g/l for the intervention and control groups, respectively. These concentrations did not change significantly following intervention. Arsenic concentrations in samples of selected raw and cooked foods from the low-contamination area did not contain less arsenic than samples from the high-contamination area. Further studies to investigate the arsenic content of food grown in areas with high and low arsenic contamination of irrigation water are recommended.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Understanding the particularly low intake of fruits and vegetables among socioeconomically disadvantaged groups is an important issue for public health. This study investigated whether access to retail outlets is similar across areas of varying socioeconomic disadvantage in an Australian urban setting, in terms of distance, the numbers of local shops, and their opening hours. This ecological cross-sectional study used 50 randomly sampled census collection districts and their nearby shopping environment (i.e. within 2.5 km), and generally found minimal or no socioeconomic differences in shopping infrastructure. Important methodological and social/economic issues may explain this contrast with overseas findings.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The antibacterial activities of water, ethanol and hexane extracts of five Australian herbs (Backhousia citriodora, Anetholea anisata, Eucalyptus staigerana, Eu. olida and Prostanthera incisa) against seven food-related bacteria (Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Enteritidis, Sal. Typhimurium and Staphylococcus aureus) were determined by the microtitre broth microdilution assay. The water extracts of all the herbs displayed no or low antimicrobial activity against all of the bacteria tested with the exception of S. aureus. Relatively high levels of activity (minimum inhibitory concentrations of 125-15.6 mu g ml(-1)) against this pathogen were present in water extracts from all herbs except P. incisa. The ethanol and hexane extracts of all herbs displayed some activity against a number of the bacteria tested, with no one particular herb displaying an obviously higher level or range of activity. Staphylococcus aureus proved to be the most sensitive of the bacteria tested against the solvent extracts with all extracts displaying activity ranging from 125 to 7.8 mu g ml(-1), while E. coli and L. monocytogenes, on the other hand, proved the least sensitive with only five of 15 herb/extract combinations displaying any activity against these pathogens. The extracts of the Australian native herbs examined in this study have potential for application in foods to increase shelf-life or promote safety. (c) 2005 Elsevier Ltd. All rights reserved.