The effects of feeding Karlodinium veneficum (PLY # 103; Gymnodinium veneficum Ballantine) to the blue mussel Mytilus edulis

The effects of exposure to the type species for Karlodinium veneficum (PLY # 103) on immune function and histopathology in the blue mussel Mytilus edulis were investigated. Mussels from Whitsand Bay, Cornwall (UK) were exposed to K. veneficum (PLY # 103) for 3 and 6 days. Assays for immune function included total and differential cells counts, phagocytosis and release of extra cellular reactive oxygen species. Histology was carried out on digestive gland and mantle tissues. The toxin cell quota for K. veneficum (PLY #103) was measured by liquid chromatography-mass spectrometry detecting two separable toxins KvTx1 (11.6 ± 5.4 ng/ml) and KvTx2 (47.7 ± 4.2 ng/ml). There were significant effects of K. veneficum exposure with increasing phagocytosis and release of reactive oxygen species following 6 days exposure. There were no significant effects on total cell counts. However, differential cell counts did show significant effects after 3 days exposure to the toxic alga. All mussels produced faeces but not pseudofaeces indicating that algae were not rejected prior to ingestion. Digestive glands showed ingestion of the algae and hemocyte infiltration after 3 days of exposure, whereas mantle tissue did not show differences between treatments. As the effects of K. veneficum were not observed in the mantle tissue it can be hypothesized that the algal concentration was not high enough, or exposure long enough, to affect all the tissues. Despite being in culture for more than 50 years the original K. veneficum isolate obtained by Mary Parke still showed toxic effects on mussels.

Gothic Territory : una aproximación a la estética burtoniana

Aquest treball té com a objectiu l'anàlisi de l'estètica cinematogràfica del director Tim Burton. Es desenvoluparà fent un recorregut pels moviments artístics que han servit d'influència al director i les experiències vitals que l'han inspirat a l'hora de construir la seva filmografia. En aquest sentit, la seva biografia és vital per entendre les temàtiques a les que sol recórrer a l'hora de realitzar un film.

Effect of chronic ethanol feeding on rat hepatocytic glutathione. Compartmentation, efflux, and response to incubation with ethanol.

Hepatocytes from rats that were fed ethanol chronically for 6-8 wk were found to have a modest decrease in cytosolic GSH (24%) and a marked decrease in mitochondrial GSH (65%) as compared with pair-fed controls. Incubation of hepatocytes from ethanol-fed rats for 4 h in modified Fisher's medium revealed a greater absolute and fractional GSH efflux rate than controls with maintenance of constant cellular GSH, indicating increased net GSH synthesis. Inhibition of gamma-glutamyltransferase had no effect on these results, which indicates that no degradation of GSH had occurred during these studies. Enhanced fractional efflux was also noted in the perfused livers from ethanol-fed rats. Incubation of hepatocytes in medium containing up to 50 mM ethanol had no effect on cellular GSH, accumulation of GSH in the medium, or cell viability. Thus, chronic ethanol feeding causes a modest fall in cytosolic and a marked fall in mitochondrial GSH. Fractional GSH efflux and therefore synthesis are increased under basal conditions by chronic ethanol feeding, whereas the cellular concentration of GSH drops to a lower steady state level. Incubation of hepatocytes with ethanol indicates that it has no direct, acute effect on hepatic GSH homeostasis.

Effect of chronic ethanol feeding on glutathione and functional integrity of mitochondria in periportal and perivenous rat hepatocytes.

Chronic ethanol feeding selectively impairs the translocation of cytosol GSH into the mitochondrial matrix. Since ethanol-induced liver cell injury is preferentially localized in the centrilobular area, we examined the hepatic acinar distribution of mitochondrial GSH transport in ethanol-fed rats. Enriched periportal (PP) and perivenous (PV) hepatocytes from pair- and ethanol-fed rats were prepared as well as mitochondria from these cells. The mitochondrial pool size of GSH was decreased in both PP and PV cells from ethanol-fed rats either as expressed per 10(6) cells or per microliter of mitochondrial matrix volume. The rate of reaccumulation of mitochondrial GSH and the linear relationship of mitochondrial to cytosol GSH from ethanol-fed mitochondria were lower for both PP and PV cells, effects observed more prominently in the PV cells. Mitochondrial functional integrity was lower in both PP and PV ethanol-fed rats, which was associated with decreased cellular ATP levels and mitochondrial membrane potential, effects which were greater in the PV cells. Mitochondrial GSH depletion by ethanol feeding preceded the onset of functional changes in mitochondria, suggesting that mitochondrial GSH is critical in maintaining a functionally competent organelle and that the greater depletion of mitochondrial GSH by ethanol feeding in PV cells could contribute to the pathogenesis of alcoholic liver disease.

A cartography of the Van der Waals territory

The distribution of distances from atoms of a particular element E to a probe atom X (oxygen in most cases), both bonded and intermolecular non-bonded contacts, has been analyzed. In general, the distribution is characterized by a maximum at short EX distances corresponding to chemical bonds, followed by a range of unpopulated distances the van der Waals gap and a second maximum at longer distances the van der Waals peak superimposed on a random distribution function that roughly follows a d3 dependence. The analysis of more than five million interatomic"non-bonded" distances has led to the proposal of a consistent set of van der Waals radii for most naturally occurring elements, and its applicability to other element pairs has been tested for a set of more than three million data, all of them compared to over one million bond distances.

Feeding of nauplii, copepodites and adults of Calanipeda aquaedulcis (Calanoida) in Mediterranean salt marshes

Feeding of the different developmental stages of Calanipeda aquaedulcis on natural particles (bacterio-, phyto- and microzooplankton) was measured in a Mediterranean salt marsh (Empordà wetlands, NE Iberian Peninsula). Bottle incubations were performed in the field both in autumn and spring. The results showed differences in the diet of the different developmental stages due to both prey type and size. In general, the size of the ingested prey increased with increasing size of the C. aquaedulcis stage. While C. aquaedulcis adults had high ingestion rates and selection coefficients for large prey (micro- and nanoplankton), nauplii preferentially consumed smaller prey items (picoplankton). Copepodites showed the widest prey size range, including pico-, nano- and microplankton. Nevertheless, the lower size limit for particle capture was similar for all stages, i.e. between 1.7 and 2.1 μm. Omnivory was observed in all stages of C. aquaedulcis. Heterotrophic prey (picoplankton, dinoflagellates and ciliates) were the most ingested items. The ability to partition the available food among the different developmental stages could represent an advantage in times of ood scarcity because it may reduce intraspecific competition. This may explain how C. aquaedulcis is able to predominate in the zooplankton community for several weeks during spring and summer ven in situations of low food availability

Applying precision feeding techniques in growing-finishing pig operations

The high cost of feed ingredients, the use of non-renewable sources of phosphate and the dramatic increase in the environmental load resulting from the excessive land application of manure are major challenges for the livestock industry. Precision feeding is proposed as an essential approach to improve the utilization of dietary nitrogen, phosphorus and other nutrients and thus reduce feeding costs and nutrient excretion. Precision feeding requires accurate knowledge of the nutritional value of feedstuffs and animal nutrient requirements, the formulation of diets in accordance with environmental constraints, and the gradual adjustment of the dietary nutrient supply to match the requirements of the animals. After the nutritional potential of feed ingredients has been precisely determined and has been improved by the addition of enzymes (e.g. phytases) or feed treatments, the addition of environmental objectives to the traditional feed formulation algorithms can promote the sustainability of the swine industry by reducing nutrient excretion in swine operations with small increases in feeding costs. Increasing the number of feeding phases can also contribute to significant reductions in nutrient excretion and feeding costs. However, the use of precision feeding techniques in which pigs are fed individually with daily tailored diets can further improve the efficiency with which pigs utilize dietary nutrients. Precision feeding involves the use of feeding techniques that allow the provision of the right amount of feed with the right composition at the right time to each pig in the herd. Using this approach, it has been estimated that feeding costs can be reduced by more than 4.6%, and nitrogen and phosphorus excretion can both be reduced by more than 38%. Moreover, the integration of precision feeding techniques into large-group production systems can provide real-time off-farm monitoring of feed and animals for optimal slaughter and production strategies, thus improving the environmental sustainability of pork production, animal well-being and meat-product quality.

Multi-scale effects of nestling diet on breeding performance in a terrestrial top predator inferred from stable isotope analysis

Inter-individual diet variation within populations is likely to have important ecological and evolutionary implications. The diet-fitness relationships at the individual level and the emerging population processes are, however, poorly understood for most avian predators inhabiting complex terrestrial ecosystems. In this study, we use an isotopic approach to assess the trophic ecology of nestlings in a long-lived raptor, the Bonelli"s eagle Aquila fasciata, and investigate whether nestling dietary breath and main prey consumption can affect the species" reproductive performance at two spatial scales: territories within populations and populations over a large geographic area. At the territory level, those breeding pairs whose nestlings consumed similar diets to the overall population (i.e. moderate consumption of preferred prey, but complemented by alternative prey categories) or those disproportionally consuming preferred prey were more likely to fledge two chicks. An increase in the diet diversity, however, related negatively with productivity. The age and replacements of breeding pair members had also an influence on productivity, with more fledglings associated to adult pairs with few replacements, as expected in long-lived species. At the population level, mean productivity was higher in those population-years with lower dietary breadth and higher diet similarity among territories, which was related to an overall higher consumption of preferred prey. Thus, we revealed a correspondence in diet-fitness relationships at two spatial scales: territories and populations. We suggest that stable isotope analyses may be a powerful tool to monitor the diet of terrestrial avian predators on large spatio-temporal scales, which could serve to detect potential changes in the availability of those prey on which predators depend for breeding. We encourage ecologists and evolutionary and conservation biologists concerned with the multi-scale fitness consequences of inter-individual variation in resource use to employ similar stable isotope-based approaches, which can be successfully applied to complex ecosystems such as the Mediterranean.

Activity patterns and foraging behaviour of Audouin's gulls at the Ebro Delta, NW Mediterranean.

Twenty Audouin´s gulls, Larus audouinii, breeding in the Ebro Delta (NW Mediterranean) were radio-tracked in 1998 to study their foraging behaviour and activity patterns. Some detrimental effects of tagging on the breeding success of the birds were detected, especially when both members of the pair were tagged. The results were actually constrained by the low number of locations due to natural breeding failure and failure in tag emission, as well as the adverse effect of tagging. However, through a combination of aircraft surveys at sea and a fixed station for automatic tracking of the presence of the birds at the colony, novel individual-based information of home ranges and activity patterns was obtained. Trawler fishing activity seemed to influence both the foraging range and habitat use: while trawlers operated, gulls overlapped their fishing grounds with vessels, probably to scavenge on discards. Very few locations were obtained during a trawling moratorium period, although they were all recorded in coastal bays and terrestrial habitats. During the trawling activity period, gulls ranged over a minimum convex polygon area of 2900 km2. Gulls were tracked up to 40 km from the colony, but some individuals were observed beyond 150 km while still breeding. Arrivals and departures from the colony were in accordance with the trawling timetable. However, most birds also showed some nocturnal foraging activity, probably linked to active fishing of clupeoids (following diel migrations) or to the exploitation of purse-seine fishing activity. Foraging trips lasted on average 15 hours: males performed significantly shorter trips than females, which spent more time outside the colony. The proportion of nocturnal time involved in the foraging trips was the same for males and females, but whilst all males initiated their trips both during the day and at night, some females only initiated their trips during the day. Hatching success was found to be related to foraging effort by males. Gulls spent on average ca. 38% of their time budget outside the nesting territory, representing the time devoted mainly to flying, foraging and other activities.

Influence of the feeding mechanism on deposits of square particles

In a previous paper [Hidalgo et al., Phys. Rev. Lett. 103, 118001 (2009)] it was shown that square particles deposited in a silo tend to align with a diagonal parallel to the gravity, giving rise to a deposit with very particular properties. Here we explore, both experimentally and numerically, the effect on these properties of the filling mechanism. In particular, we modify the volume fraction of the initial configuration from which the grains are deposited. Starting from a very dilute case, increasing the volume fraction results in an enhancement of the disorder in the final deposit characterized by a decrease of the final packing fraction and a reduction of the number of particles oriented with their diagonal in the direction of gravity. However, for very high initial volume fractions, the final packing fraction increases again. This result implies that two deposits with the same final packing fraction can be obtained from very different initial conditions. The structural properties of such deposits are analyzed, revealing that, although the final volume fraction is the same, their micromechanical properties notably differ.

Feeding habits of Ophichthus rufus (Anguilliformes, Ophichthidae) in the western Mediterranean

Ophichthus Rufus is a Mediterranean benthic fish with nocturnal habits. It lives in sand or mud bottoms at depths between 50 and 150m. Until now, nothing about its feeding habits was known. Stomach contents of 689 individuals, collected between 1985 and 1987, were analysed. The diet is basically composed of benthic organisms, among which the decapods processa canaliculata and Alpheus glaber and the teleost fish Callionymus maculatus are prominent. Young of both sexes and adult males have a euryphagic carnivorous diet, whereas adult females are closer to a stenophagic piscivorous diet

Observations on the feeding habits of the narrow mouthed cat shark Schroederichthys bivius (Chondrichthyes, Scyliorhinidae) in the Beagle Channel

The study of the stomach contents of 97 specimens of the narrow mouthed cat shark Schroederichthys bivius shows that their basic food consists of crabs, mainly Munida subrugosa. No significant variations were observed between size classes. The strongly developed sexual dimorphism in Touch morphology and mouth shape was not correlated with the diet of males and females