Weighing used for the automatic registration of preferences when testing rats

The preference test is one of the only behavioural test, which gives the animal an opportunity to make a free choice or indicate what it prefers and, therefore, it is widely used to evaluate whether an animal prefers one set-up to another. Providingwhat the experimental animal prefers (eg grids) will reduce stress, good for both experimental reliability and animal welfare.In the present study the rat’s preference for different cages was registered and recorded by digital weights This study showed that this relatively simple set-up was applicable for registration of the preferences for different housing conditions, such as bedding or grid

The application of traditional behavioural and physiological methods for monitoring of the welfare impact of different flooring conditions in rodents

In this study, observations on traditional methods, such as open field test, conicosterone assays and monitoring of barbiturate sleeping time, were performed to validate the impact of housing conditions on the welfare of rats and mice in orderto compare the outcome with observations previously achieved by preference tests and telemetry. These traditional methods failed to demonstrate the impact on the animals caused by grid housing previously shown by telemetry and preference studies, and it is, therefore, concluded that these traditional tests may be less sensitive for monitoring Subtle small environmental impacts on laboratory rodents.Although. the methods were not able to reveal any differences in eortieosterone level and open field test between housing conditions, there were significant differences between mouse strains and sexes. These differences between strains should betaken i nto account when choosing the best suitable strain for a study

Zygotic Genome Activation Occurs Shortly After Fertilization in Maize

The formation of a zygote via the fusion of an egg and sperm cell and its subsequent asymmetric division herald the start of the plant's life cycle. Zygotic genome activation (ZGA) is thought to occur gradually, with the initial steps of zygote and embryo development being primarily maternally controlled, and subsequent steps being governed by the zygotic genome. Here, using maize (Zea mays) as a model plant system, we determined the timing of zygote development and generated RNA-seq transcriptome profiles of gametes, zygotes, and apical and basal daughter cells. ZGA occurs shortly after fertilization and involves similar to 10% of the genome being activated in a highly dynamic pattern. In particular, genes encoding transcriptional regulators of various families are activated shortly after fertilization. Further analyses suggested that chromatin assembly is strongly modified after fertilization, that the egg cell is primed to activate the translational machinery, and that hormones likely play a minor role in the initial steps of early embryo development in maize. Our findings provide important insights into gamete and zygote activity in plants, and our RNA-seq transcriptome profiles represent a comprehensive, unique RNA-seq data set that can be used by the research community

UV friendly T-parity in the SU(6)/Sp(6) little Higgs model

Electroweak precision tests put stringent constraints on the parameter space of little Higgs models. Tree-level exchange of TeV scale particles in a generic little Higgs model produce higher dimensional operators that make contributions to electroweak observables that are typically too large. To avoid this problem a discrete symmetry dubbed T-parity can be introduced to forbid the dangerous couplings. However, it was realized that in simple group models such as the littlest Higgs model, the implementation of T-parity in a UV completion could present some challenges. The situation is analogous to the one in QCD where the pion can easily be defined as being odd under a new $Z_2$ symmetry in the chiral Lagrangian, but this $Z_2$ is not a symmetry of the quark Lagrangian. In this paper we examine the possibility of implementing a T-parity in the low energy $SU(6)/Sp(6)$ model that might be easier to realize in the UV. In our model, the T-parity acts on the low energy non-linear sigma model field in way which is different to what was originally proposed for the Littlest Higgs, and lead to a different low energy theory. In particular, the Higgs sector of this model is a inert two Higgs doublets model with an approximate custodial symmetry. We examine the contributions of the various sectors of the model to electroweak precision data, and to the dark matter abundance.Comment: 21 pages,4 figures. Clarifications added, typos corrected and references added. Published in JHE

Electromagnetic Form Factors of the Nucleon in an Improved Quark Model

Nucleon electromagnetic form factors are studied in the cloudy bag model (CBM) with center-of-mass and recoil corrections. This is the first presentation of a full set of nucleon form factors using the CBM. The center of mass motion is eliminated via several different momentum projection techniques and the results are compared. It is found that the shapes of these form factors are significantly improved with respect to the experimental data if the Lorentz contraction of the internal structure of the baryon is also appropriately taken into account.Comment: revtex, 28 pages, 8 ps figs include

Ponded craters on Vesta

Ponded craters have been predominantly identified on small, dry planetary bodies like (433) Eros and Itokawa. We identified similar features on Vesta, where loose fragmented ponded materials are present on small crater floors. While the morphological details of the ponded features on Vesta and Eros/Itokawa are similar, their production mechanisms may vary, due to differences in gravity or the insolation environment Previous studies conducted on Vesta have provided evidence for volatile outgassing in some regions. In this study, we investigate the morphology of the ponded crater and possible involvement of volatiles outgassing and its interaction with surface material in producing ponded craters on Vesta

Formation of Ejecta and Dust Pond Deposits on Asteroid Vesta

Dust and melt ponds have been studied on planetary bodies including Eros, Itokawa, and the Moon. However, depending on the nature of the regolith material properties and the location of the planetary body, the formation mechanism of the ponded features varies. On Eros and Itokawa, ponded features are formed from dry regolith materials whereas on the Moon similar features are thought to be produced by ejecta melt. On the surface of Vesta, we have identified type 1, ejecta ponds, and type 2, dust ponds. On Vesta type 1 pond are located in the vicinity of ejecta melt of large impact craters. The material is uniformly distributed across the crater floor producing smooth pond surfaces which have a constant slope and shallow depth. The hosting crater of melt-like ponds has a low raised rim and is located on relatively low elevated regions. Whereas, the type 2 ponds on Vesta reveal an undulating surface that is frequently displaced from the crater center or extends toward the crater wall with an abruptly changing slope. We suggested that for the production of the type 2 ponds, localized seismic diffusion and volatile-induced fluidization may be responsible for Vesta. Due to Vesta's large size (in comparison to Eros and Itokawa), the surface may have experienced local-scale rare high-amplitude seismic diffusion which was sufficient to drift fine material. Similarly, short-lived volatile activities were capable to transfer dusty material on to the surface. Segregation and smoothing of transferred material lack further surface activities, hindering the formation of smooth morphology