Search results for "PRI"

Elevated oxidative stress in pied flycatcher nestlings of eumelanic foster fathers under low rearing temperatures

2019

Striking variation in melanin coloration within natural populations is likely due to the different fitness outcomes of alternative phenotypes in varying environmental conditions. There are two types of melanin: eumelanins yield blackish hues, whereas pheomelanins yield reddish hues. The production of eumelanins requires low levels of glutathione (GSH), which is the most important intracellular antioxidant, whereas the production of pheomelanins requires high levels of GSH. We investigated the oxidative status of male pied flycatchers (Ficedula hypoleuca) with different degrees of melanin coloration under different temperatures during the nestling period. Moreover, we assessed the oxidative …

Chemical fingerprints suggest direct familiarisation rather than phenotype matching during olfactory recognition in Australian sea lions (Neophoca ci…

2019

International audience; Olfaction is one of the most commonly used senses for communication among animals and is of particular importance to mother-offspring recognition in mammals. The use of smell in offspring recognition has been well studied, however, we often lack information about the underlying mechanistic basis for olfactory recognition. Using gas chromatography–mass spectrometry (GC–MS), we examine chemical profiles of two different colonies of Australian sea lions (Neophoca cinerea) and assess similarity of chemical fingerprints in mother-pup pairs. This analysis allows us to examine whether a chemical base for phenotype matching exists in this species. Our results showed no GC-de…

High-pressure processing of meat and meat products

2016

International audience; High pressure (HP) was first introduced at the end of the nineteenth century in the field of materials chemistry. The first application of high pressure in the food industry was proposed by Hite in 1899 to pasteurize milk and fruit products. The high hydrostatic pressure (HHP) treatment is considered as a nonthermal process, alternative to heat treatments, as it enables inactivation of pathogenic and spoilage microorganisms in foods. This technology is based on two principles that determine the behavior of foods under pressure. The first is an important principle that underlies the effects on reaction equilibria is known as the principle of Le Chatelier, and the seco…

Differential expression and costs between maternally and paternally derived immune priming for offspring in an insect

2011

1. When parasitized, both vertebrates and invertebrates can enhance the immune defence of their offspring, although this transfer of immunity is achieved by different mechanisms. In some insects, immune-challenged males can also initiate trans-generational immune priming (TGIP), but its expressions appear qualitatively different from the one induced by females similarly challenged. 2. The existence of male TGIP challenges the traditional view of the parental investment theory, which predicts that females should invest more into their progeny than males. However, sexual dimorphism in life-history strategies and the potential costs associated with TGIP may nevertheless lead to dissymmetric in…

Relationship between maternal transfer of immunity and mother fecundity in an insect.

2012

Trans-generational immune priming (TGIP) corresponds to the plastic adjustment of offspring immunity as a result of maternal immune experience. TGIP is expected to improve mother's fitness by improving offspring individual performance in an environment where parasitism becomes more prevalent. However, it was recently demonstrated that maternal transfer of immunity to the offspring is costly for immune-challenged female insects. Thus, these females might not provide immune protection to all their offspring because of the inherent cost of other fitness-related traits. Females are therefore expected to adjust their investment to individual offspring immune protection in ways that maximize the…

Aggressive interactions between juvenile swordfishes and blue sharks in the Western Mediterranean: a widespread phenomenon?

2019

There are numerous reports of billfishes spearing objects, marine organisms, and even humans. Whether or not this behaviour is intentional and, if so, what is its functional meaning, are open questions. In 2016, an adult blue shark (Prionace glauca) was found to be killed by a juvenile swordfish (Xiphias gladius) in the western Mediterranean. Here we report on three more recent cases involving both species in the same area. In February 2017, an adult male blue shark was found stranded in Garrucha (Spain) with a fragment of a juvenile swordfish’s rostrum (18cm long x 2cm wide at proximal end) inserted in its cranium. In March 2017, an adult pregnant female blue shark was stranded alive on th…

Analysis of trematode parasite communities in fish eye lenses by pyrosequencing of naturally pooled DNA.

2011

Infections by multiple parasite species are common in nature and have important consequences for between species interactions and coevolutionary dynamics with the host populations. For example ecological and evolutionary factors underlying the structure of parasite communities determine the range of hosts a parasite can infect and set the basis for both evolution of host defences and parasite virulence as well as management of diseases. Studies investigating these factors have been facilitated in the recent past by genetic methods which surmount difficulties of traditional morphological taxonomy in identifying individual parasite species. Here we take a step further and present a novel meth…

Bioluminescent-like squamation in the galeomorph shark Apristurus ampliceps (Chondrichthyes: Elasmobranchii)

2018

Galeomorph sharks constitute the most taxonomically and ecologically diverse superorder of living selachians. Despite comprising several typically deep-water taxa, no bioluminescent species have been reported in this group so far. Interestingly, the study of shark squamation has been revealed in recent years to be a good proxy for inferring some ecological aspects of poorly known species. In particular, the high morphological specificity of the dermal denticles and the squamation patterns of all currently-known bioluminescent sharks could constitute a potential tool for predicting bioluminescence in both fossil and living taxa. Following this idea, we provide the first evidence supporting t…

2017

The genus Dipsacus is characterized by a remarkable bidirectional flowering sequence and a rare phyllotactic pattern. Considering that flower initiation and flowering sequence may be interconnected, we document the development of the head meristem in Dipsacus fullonum. Our results indicate a gradual change in the geometry of the head meristem beginning with a dome shaped stage, continuing with a remarkable widening in the middle part of the head meristem and ending in a spindle-like form. Quantitative data confirm that meristem expansion is higher in the middle part than at the base of the meristem. Likewise, the size of the flower primordia in the middle part of the young head is significa…

Biochemical Composition of Spring Barley Grain Pearled to Varying Degrees

2017

Abstract Differences in biochemical composition in dehulled and pearled grain samples affected by the various degrees of pearling were studied for spring barley (Hordeum vulgare L.). Twelve covered spring barley and two hulless genotypes were examined. Commercial samples of pearled barley were included for comparison. Covered barley grain samples were pearled using a small-scale barley pearler to obtain dehulled and pearled barley grain products with pearling percentage of 12% and 30%, respectively. Significant differences were observed in the chemical composition between dehulled grain and pearled grain. As the outer layers of the covered grain were removed to a greater degree by pearling,…