Feeding increases 5-hydroxytryptamine and norepinephrine within the hypothalamus of chicks

It is thought that hypothalamic 5-hydroxytryptamine (5HT) and norepinephrine (NE) are involved in the regulation of feeding in chicks. The present study was conducted to elucidate changes in the levels of extracellular 5HT and NE in the hypothalamus during feeding of chicks. In order to measure 5HT, NE and 4-hydroxy-3-methoxyphenylglycol (MHPG), which is a major metabolite of NE, we used brain microdialysis and high-pressure liquid chromatography with an electrochemical detector. After collecting samples to determine the basal levels of 5HT, NE and MHPG, food-deprived birds were given access to food. 5HT levels in the medial hypothalamus (MH) and lateral hypothalamus (LH) increased during the first 30 min of feeding, and then returned to basal levels. NE and MHPG in the LH increased during feeding, and remained elevated throughout the experiment. This study supports an idea that hypothalamic monoamines in the chick brain are involved in the regulation of feeding.     

Feeding ecology of indigenous and non-indigenous fish species within the family Sphyraenidae

The feeding ecology of two common indigenous (Sphyraena viridensis and Sphyraena sphyraena) and one abundant non-indigenous sphyraenid species, Sphyraena chrysotaenia, of Indo-Pacific Ocean origin, was investigated in an area of the eastern Mediterranean Sea. The stomach contents of 738 individuals of varying size, collected during the period December 2008 to August 2009, were examined. The dietary analyses revealed that all three species were specialized piscivores with a diet consisting of >90% fish, both by number and mass. Concurrent sampling of the fish assemblage made it possible to calculate selectivity as well as diet breadth and overlap of these strict piscivores. Even though several prey species were found in the stomachs of the three predators examined, selectivity towards Atherina boyeri was highly significant. For all species examined, >70% of the diet by mass was made up by three indigenous species of commercial value: Spicara smaris, Boops boops and A. boyeri. Diet breadth and size of prey increased with increasing body size for all predators. With increased body size, the diet overlap between indigenous and non-indigenous species decreased. This could be attributed to increased diet breadth and the specific life-history characteristics of indigenous species developing into larger individuals. During winter, the condition factor of the non-indigenous species was significantly lower than that of the indigenous, indicating that winter conditions in the Mediterranean Sea may limit its further expansion north and westward. With this study, the gap in knowledge of the feeding preferences of the most abundant piscivorous species found in coastal areas of the study region is filled. Additionally, the results indicate that non-indigenous species familial affiliation to indigenous ones does not facilitate invasion success.     

In vitro tests within the REACH information strategies

Tonnage-based information requirements are specified in the proposal on the regulation on the Registration, Evaluation and Authorisation of Chemicals (REACH) in the European Union. The hazard assessment for toxic endpoints should be performed by using a tiered approach, i.e. as an information strategy (IS), starting with an evaluation of all of the data already available, including animal in vivo and in vitro data, and human evidence and case reports, as well as data from (Quantitative)-Structure Activity Relationships ([Q]SARs) or read-across, before any further testing is suggested. To contribute to the implementation of the REACH system, the Nordic countries launched two projects: 1) a review of currently used testing strategies, including a comparison with the REACH requirements; and 2) the development of detailed ISs for skin and eye irritation/corrosion. The review showed that the ISs and classification criteria for the selected endpoints are inconsistent in many cases. In the classification criteria, human data and in vivo test results are usually the prerequisites. Other types of information, such as data from in vitro studies, can sometimes be used, but usually as supportive evidence only. This differs from the REACH ISs, where QSARs, read-across and in vitro testing are important elements. In the other part of the project, an IS for skin and eye irritation/corrosion was proposed. The strategy was "tested" by using four high production volume (HPV) chemicals: hydrogen peroxide, methyl tertiary-butyl ether (MTBE), trivalent chromium, and diantimony trioxide, but only MTBE and trivalent chromium are dealt with in this paper. The "test" revealed that in vivo data, human case reports and physical-chemical data were available and could be used in the evaluation. Classification could be based on the proposed IS and the existing data in all cases, except for the eye irritation/corrosion of trivalent chromium. Weight-of-evidence analysis appeared to be a useful step in the ISs proposed, and including it in the REACH strategies should be considered. For these chemicals, few in vitro and (Q)SAR data were available--more of these data would be generated, if the relevant guidance and legislation on classification were updated.     

Estimating the twist of beta-strands embedded within a regular parallel beta-barrel structure

The parallel beta-barrel is a recurrent structural motif found in a large variety of different enzymes belonging to the family of alpha/beta-proteins. It has been shown previously that the hyperboloid can be considered as a scaffold describing the parallel beta-barrel structure. To assess restraints on beta-strand twist imposed by a given scaffold geometry, the notion of scaffold twist, Ts, is introduced. From Ts, the beta-strand twist (Tw beta) expected for a given scaffold geometry can be derived and it is verified that this computed twist can be used to identify beta-barrels characterized by good hydrogen bonding. It is noted that Tw beta is only slightly affected for beta-barrels differing in the number (N) of beta-strands, suggesting that restraints on main-chain conformation of beta-strands are not likely to account for the N = 8 invariability observed in natural parallel beta-barrels thereby strengthening previous work rationalizing this constancy.     

Feeding mechanisms in bats: variation within the constraints of flight

By any standard, bats are a successful group of mammals andthe evolution of flight and echolocation were certainly keyinnovations behind their success. That is only part of the story,however. Bats have diversified into trophic niches that rangefrom insectivory to feeding on blood, fruit, or nectar. Whileflight places fundamental constraints on the shape of the postcranialskeleton, skull shape in bats is remarkably diverse. Morphologicalstudies of individual families and sympatric assemblages demonstratethat variation in skull shape is clearly associated with trophicspecialization. Field experiments demonstrate that species-specificbiting behaviors during feeding are common and analyses indicatethat the evolution of cranial morphology and feeding behaviorare correlated. Modeling experiments further suggest that feeding(loading) behaviors and skull shape are functionally linked.If the skulls of bats are under selective pressure for minimalmass because of the energetic demands of flight, then they maybe more "optimized" to meet mechanical demands than are theskulls of other mammals. This would make bats a unique modelsystem for studying the evolution of diversity in skull shapeand its functional implications for the evolution of feedingstrategies in mammals.     

Performance of cyprinids in non-reversing mirrors versus regular mirrors in tests of aggressiveness

Journal of Ethology - Mirror tests have been used to test aggressiveness because they reduce the variability of the real opponent and allows for repeated measurements. Regular mirrors have also...     

Feeding tests with ducklings,Turkey chicks and rabbits and the effects of aflatoxin on these animals

The effects of feeding animals with a toxic strain ofA. flavus was examined. The animals examined were ducklings, turkeys and rabbits. All of them showed loss of weight and mortality after feeding with aflatoxin.The livers of those animals showed that aflatoxin caused pathological changes. This damage of the liver is the lethal effect of the aflatoxin.

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Zusammenfassung Die Wirkung der Fütterung von Tieren mit einem toxischen Stamm vonA. flavus wurde untersucht. Die Tiere sind Entchen, Truthähnchen und Hasen. Alle zeigten einen Gewichtverlust und eine Mortalität nach Aflatoxin-Fütterung. Die Leber der Tiere zeigte, daß Aflatoxin pathologische Veränderung herbeiführte. Die Leberschädigung ist die tötliche Wirkung des Aflatoxins.

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Research supported by grant number FG-Is-161 of the United States Department of Agriculture to whom the author is indebted.     

Feeding by the Whitebacked Planthopper,Sogatella furcifera,within susceptible and resistant rice varieties

Prise de nourriture par Sogatella furcifera sur des variétés de riz sensibles ou résistantes Des déterminations des taux d'ingestion et des sites de prise de nourriture par Sogatella furcifera, faites indirectement par des estimations du pH. du contenu en acides aminés libres et de la quantité de miellat excrété par cet Homoptère sur une variété sensible (TN1) et une variété résistante (IR2035-117-3) de riz. Oriza sativa L., suggèrent que le taux d'ingestion de sève est 267 fois plus élevé sur la variété TN1, bien que le site principal de la prise de nourriture sur les 2 variétés semble se situer au niveau de la sève élaborée des tubes criblés du liber (phloème). Ces résultats sont comparés à ceux publiés antérieurement sur la cicadelle du riz. Nephotettix virescens, dont le taux d'ingestion est semblable sur des variétés de riz sensibles ou résistantes, mais dont les sites de prise de nourriture sont différents. Cette cicadelle se nourrirait principalement de la sève élaborée du phloème chez la variété TN1, tandis qu'elle absorberait surtout de la sève brute provenant des vaisseaux du bois (xylème) chez des variétés de riz résistantes aux attaques de ce déprédateur.     

Excluded volume effect within the continuous model for the fluorescence energy transfer

We consider and discuss the transfer of electronic energy between donor and acceptor molecules, both continuously distributed in an infinite space. In particular, the ensemble-average fluorescence intensity decay for the donor was calculated, taking into account the excluded volume. The latter may be associated either with finite molecular size or any other spatial restrictions, which are imposed on fluorophore distribution by a superstructure. Results show that in a system using excluded volume, the time dependence in donor decay is more complex compared to that predicted by a simplified stretched exponential model. We identify a crossover between two distinct time regimes in the refined decay and demonstrate its correlation with two competing parameters: r(m), which characterizes the minimal distance between interacting molecules, and R(0), which is related to the strength of the molecular interactions. In this context, the "apparent dimensionality" of the energy transfer recovered from the stretched exponential model ignores the crossover, and may be quite misleading. Basic theoretical considerations to that end are provided.     

Understanding FDA regulation of DTC genetic tests within the context of administrative law

How the FDA should regulate direct-to-consumer genetic tests is fiercely contested. Passing a rule or issuing an order is only one down in the series. There is more to the regulatory game.     

Feeding competition within a feral goat population on the Isle of Rum, NW Scotland

This study investigated feeding competition within and between different age–sex classes of feral goats (Capra hircus) on the Isle of Rum (northwest Scotland) from August to November 2000 (inclusive). Although contests in a feeding context were common, most were relatively passive: little overt agonistic behaviour was observed between opponents and the distance between feeding animals involved did not change significantly after an interaction. Month (but not sex or habitat type) had a significant effect on feeding interaction rates, and the proportion of interactions involving more intense forms of conflict was highest in November when forage availability was beginning to decline. The results show that the initiator won most feeding encounters, with adult males being dominant over females. The ability to win conflicts increased with age for both males and females. However, it decreased sharply for adult males older than 5 years, which may, in part, explain the reduced overwinter survival of these individuals.