Differentially expressed genes for aggressive pecking behaviour in laying hens

BACKGROUND: Aggressive behaviour is an important aspect in the daily lives of animals living in groups. Aggressive animals have advantages, such as better access to food or territories, and they produce more offspring than low ranking animals. The social hierarchy in chickens is measured using the 'pecking order' concept, which counts the number of aggressive pecks given and received. To date, little is known about the underlying genetics of the 'pecking order'. RESULTS: A total of 60 hens from a high feather pecking selection line were divided into three groups: only receivers (R), only peckers (P) and mixed peckers and receivers (P&R). In comparing the R and P groups, we observed that there were 40 differentially expressed genes [false discovery rate (FDR) P < 0.10]. It was not fully clear how the 40 genes regulated aggressive behaviour; however, gene set analysis detected a number of GO identifiers, which were potentially involved in aggressive behavioural processes. These genes code for synaptosomes (GO:0019797), and proteins involved in the regulation of the excitatory postsynaptic membrane potential (GO:0060079), the regulation of the membrane potential (GO:0042391), and glutamate receptor binding (GO:0035254). CONCLUSION: In conclusion, our study provides new insights into which genes are involved in aggressive behaviours in chickens. Pecking and receiving hens exhibited different gene expression profiles in their brains. Following confirmation, the identification of differentially expressed genes may elucidate how the pecking order forms in laying hens at a molecular level

Positron emission tomography for quality assurance in proton therapy

To verify the dose delivery of proton therapy for cancer irradiation, secondary signals need to be measured since the protons stop at the end of their range inside the patient. The most-often used techniques currently are positron emission tomography (PET) and prompt gamma ray imaging. PET is the oldest method used to verify the dose delivery from proton therapy, but its disadvantage is the delayed feedback due to the half-life of the radioactive decay. Imaging of nuclides with a short half-life can overcome this obstacle.In this thesis, imaging of the most-promising short-lived nuclides is investigated. The results of a proof-of-principle experiment of beam-on PET imaging of short-lived 12-N nuclei are presented. A method was developed to subtract the long-lived background signal from the 12-N image by introducing a beam-off period into the cyclotron beam time structure. This allows the isolation of the 12-N contribution. A range shift of 5 mm was measured as 6 +- 3 mm using the 1D 12-N profile. A simulation shows that a large dual panel scanner that images a single spot at the beginning of the dose delivery, can measure a 5 mm range shift with millimeter accuracy.A series of clinically realistic simulation studies was performed to investigate the high-level choices that arise when considering a dose delivery verification system. Based on the simulation of the production of prompt gamma ray and positron emitting nuclides, no imaging modality and protocol can be recommended that will produce the best information on the deviations with respect to the treatment plan for all situations

Ezra Pound: The Genius in the Bughouse: Review of \u3ci\u3e I Cease Not to Yowl : Ezra Pound\u27s Letters to Olivia Rossetti Agresti\u3ci\u3e, ed. Demetres P. Tryphonopoulos and Leon Surette.

I mention this personal encounter because in this volume of letters from Pound to Olivia Rossetti Agresti, mostly written from St. Elizabeths, there is not a single mention of the. conditions under which he was living. He had been confined to the hospital in January 1946 after being adjudged by psychiatrists eccentric, querulous, and egocentric, and unfit to stand trial for treason as a consequence of broadcasting over Rome radio during the war. For a year, he was housed in a barred cell in the criminal ward, then released to a general ward, and finally, toward the end of his imprisonment in 1958 allowed a pnvate room and the freedom of the hospital garden. Pound endured this incarceration with a stoicism and serenity little short of miraculous. He was allowed access to writing materials and books and, later on, unlimited visitors, and he maintained a voluminous correspondence. His visits were like impromptu seminars or, more often, monologues, during which he kept up a ceaseless flow of ideas and homilies

Crystallization Kinetics of Colloidal Spheres under Stationary Shear Flow

A systematic experimental study of dispersions of charged colloidal spheres is presented on the effect of steady shear flow on nucleation and crystal-growth rates. In addition, the non-equilibrium phase diagram as far as the melting line is concerned is measured. Shear flow is found to strongly affect induction times, crystal growth rates and the location of the melting line. The main findings are that (i) the crystal growth rate for a given concentration exhibits a maximum as a function of the shear rate, (ii) contrary to the monotonous increase of the growth rate with increasing concentration in the absence of flow, a maximum of the crystal growth rate as a function of concentration is observed for sheared systems, and (iii) the induction time for a given concentration exhibits a maximum as a function of the shear rate. These findings will be partly explained on a qualitative level.Comment: 17 pages, 10 figures, accepted in Langmui

The Latte Gold Zone, Kaminak\u27s Coffee Gold Project, Yukon, Canada: Geology, Geochemistry, and Metallogeny

The Latte Gold Zone is hosted within complexly tectonically imbricated metamorphic rocks of the Yukon-Tanana terrane. Snowcap assemblage psammitic schist and amphibolite with exotic Slide Mountain ultramafics overthrusts unidentified arc metavolcanics which in turn overthrust the Late Permian Sulphur Creek orthogneiss. Rapid unroofing of the Dawson Range during the Mid-Cretaceous culminated in dextral movement along the Coffee Creek fault system. A set of stacked, ESE–WNW trending, steeply dipping brittle fault structures served as conduits for gold-bearing fluids. Core-logging, detailed petrography, microprobe analysis, and PIMA investigations indicate that Latte is an epizonal orogenic gold deposit. Gold is hosted within arsenian pyrite in association with dolomite and illite, and was deposited by a CO2-H2O-As-Sb-S-Ag-Au fluid between 220 and 250° C which sulphidized metamorphic mica. Primary gold disseminations are locally remobilized by a CO2-rich fluid and re-deposited within arsenian pyrite in breccias and dolomite-quartz veinlets

A comparative study of the life history and foraging behaviour of aphid hyperparasitoids

Les hyperparasitoïdes sont des guêpes parasitoïdes des parasitoïdes primaires. Au sein d’un écosystème, ils occupent le quatrième niveau trophique. Une meilleure connaissance de la biologie et du comportement des hyperparasitoïdes est indispensable pour comprendre leur relation avec les parasitoïdes et leur rôle dans les écosystèmes. Dans cette étude, quatre espèces d’hyperparasitoïdes de pucerons différant quant à leur phylogénie, mode de développement (koinobionte vs. idiobionte), stades d’hôte attaqués, et spécificité parasitaire ont été choisies: Dendrocerus carpenteri (Curtis) (Megaspilidae), Asaphes suspensus Walker (Pteromalidae), Alloxysta victrix (Westwood) (Alloxystidae) et Syrphophagus aphidivorus (Mayr) (Encyrtidae). Au laboratoire, j’ai comparé leurs paramètres d’histoire de vie et comportements de recherche par une approche comparative directe au sein du système trophique: pomme de terre (Solanum tuberosum L.); puceron de la pomme de terre, Macrosiphum euphorbiae (Thomas); parasitoïde hôte Aphidius nigripes Ashmead. Les résultats ont révélé une grande variation interspécifique des paramètres d’histoire de vie des hyperparasitoïdes. Cette variation n’a pu être attribuée exclusivement à la dichotomie du mode de développement (koinobionte ou idiobionte), tel que démontré pour les parasitoïdes primaires. L’hyperparasitoïde S. aphidivorus est atypique, ayant la capacité d’attaquer soit la larve parasitoïde dans le puceron vivant, soit sa pupe après la momification du puceron. Les femelles préféraient cet hôte, lequel s’est également avéré le plus convenable au développement. Des tests d’olfactométrie et des observations comportementales ont révélé que les femelles hyperparasitoïdes en quête d’hôtes ne seraient pas attirées à distance par des odeurs. Toutefois, elles utilisent des stimuli de contact sur la plante afin de localiser leur hôte. À ce niveau, le miellat de puceron est apparu comme l’un des principaux stimuli utilisés par les femelles, lesquelles discriminaient entre le miellat de puceron et celui de cochenille, Coccus hesperidum, n’abritant pas d’hôtes potentiels. Par contre, les femelles hyperparasitoïdes n’ont pas distingué le miellat de pucerons sains non-parasités, et celui de pucerons parasités par A. nigripes. Cette étude indique que plusieurs facteurs influencent simultanément l’histoire de vie des hyperparasitoïdes de pucerons. Leur subdivision habituelle en endoparasitoïdes koinobiontes de larves parasitoïdes dans les pucerons vivants, et ectoparasitoïdes idiobiontes de pupes de parasitoïdes dans les pucerons momifiés ne traduit pas toutes les différences interspécifiques observées. Des différences d’ordre phylogénique seraient également importantes, ces espèces provenant de taxons différents. A bien des égards, les paramètres de vie et le comportement des hyperparasitoïdes de pucerons diffèrent de ceux des parasitoïdes primaires de pucerons.Hyperparasitoids are parasitic wasps that attack primary parasitoids. They constitute the fourth trophic level in many ecosystems. A better understanding of hyperparasitoid biology and behaviour is needed to unravel the nature of parasitoid - hyperparasitoid interactions and their role in the functioning of communities and ecosystems. In this thesis, the life history traits and host searching behaviour of aphid hyperparasitoids are studied using a direct comparative approach. Four species were chosen that differ in development mode (koinobiont or idiobiont), host stage attacked and host range: Dendrocerus carpenteri (Curtis) (Megaspilidae), Asaphes suspensus Walker (Pteromalidae), Alloxysta victrix (Westwood) (Alloxystidae) et Syrphophagus aphidivorus (Mayr) (Encyrtidae) have been studied on the same potato (Solanum tuberosum L.), potato aphid (Macrosiphum euphorbiae (Thomas)) and primary parasitoid (Aphidius nigripes Ashmead) system. The results revealed a large variation in life history traits between species, which could not be explained simply by dichotomy in development mode, as proposed for primary parasitoids. The hyperparasitoid S. aphidivorus is special because females can attack the parasitoid host in the still-living aphid, or in the mummified aphid. Female S. aphidivorus had a preference for aphid mummies, which also contain the most profitable host stage for hyperparasitoid development. Olfactometer tests and behavioural observations indicated that searching hyperparasitoid females were not attracted by olfactory cues. However, they clearly reacted to host-related contact cues while searching on a plant. Here, honeydew was one of the principal contact cues used by female hyperparasitoids to locate hosts. Females discriminated between honeydew from an aphid host and that from a non-host, the soft brown scale, Coccus hesperidum, but made no difference between honeydew from healthy, unparasitised aphids, and those parasitised by A. nigripes. This study indicates that several factors probably act simultaneaously on life history strategies. The simple classification of aphid hyperparasitoids as koinobiont endoparasitoids of parasitoid larvae in living aphids, or idiobiont ectoparasitoids of parasitoid pupae in mummified aphids does not explain all observed interspecific differences. Lineage specific effects must also be important, as the species belong to different taxa. Finally, in many aspects, the life history parameters and behaviour of aphid hyperparastoids differ from those reported for primary aphid parasitoids

Anisotropic de Gennes narrowing in confined fluids

The collective diffusion of dense fluids in spatial confinement was studied by combining high-energy (21 keV) x-ray photon correlation spectroscopy and small-angle x-ray scattering from colloid-filled microfluidic channels. We found the structural relaxation in confinement to be slower compared to bulk. The collective dynamics is wave vector dependent, akin to de Gennes narrowing typically observed in bulk fluids. However, in stark contrast to bulk, the structure factor and de Gennes narrowing in confinement are anisotropic. These experimental observations are essential in order to develop a microscopic theoretical description of collective diffusion of dense fluids in confined geometries.Comment: 5 pages, 2 figures, accepted for publication in Phys Rev Let