Energy allocation and behaviour in the growing broiler chicken

Broiler chickens are increasingly at the forefront of global meat production but the consequences of fast growth and selection for an increase in body mass on bird health are an ongoing concern for industry and consumers. To better understand the implications of selection we evaluated energetics and behaviour over the 6-week hatch-to-slaughter developmental period in a commercial broiler. The effect of posture on resting metabolic rate becomes increasingly significant as broilers grow, as standing became more energetically expensive than sitting. The proportion of overall metabolic rate accounted for by locomotor behaviour decreased over development, corresponding to declining activity levels, mean and peak walking speeds. These data are consistent with the inference that broilers allocate energy to activity within a constrained metabolic budget and that there is a reducing metabolic scope for exercise throughout their development. Comparison with similarly sized galliforms reveals that locomotion is relatively energetically expensive in broilers

The local iron age pottery from selected strata at Tel Yin'am, eastern lower Galilee, Israel

Tel Yin’am and nearby Khirbet Beit Gan are the only excavated sites in the Yavne’el Valley, which constituted part of an ancient international highway that connected the hinterland of the Hauran (modern-day Syria) with the Mediterranean coast. As one of the few multi-occupational, small rural sites excavated in the Eastern Lower Galilee, Tel Yin’am, which was occupied intermittently from the Neolithic period to the Roman period (6500 BCE-325 CE), provides a critical link in the occupation history and material culture of northern (modern-day) Israel. Concentrating on critical selected Iron Age strata (1200-732 BC), this study focuses on the mostly unpublished domestic pottery assemblages, subjecting the various ceramic forms to classification and development analysis, and comparing them to contemporary pottery assemblages from proximate and distant, rural and urban sites in Cisjordan and Transjordan. Through diachronic and synchronic analyses, I succeeded in: 1) developing a picture of the ceramic history of domestic types at Tel Yin’am during the Iron Age; 2) providing both relative and absolute dates for this ceramic assemblage; 3) placing the assemblage into the broader ceramic context of the Iron Age in northern Cisjordan and Transjordan; 4) highlighting the important role of roads and ancient highways and how they impacted on the history of Tel Yin’am and its material culture in the Iron Age, thereby closing a gap in the knowledge of the history of rural life and culture in the Yavne’el Valley in the Iron Age; and 5) gaining an understanding of the approximately 500-year history of consistent and changing points of contact between Tel Yin’am and other sites that lay along the highways traversing the northern Lower Galilee.Middle Eastern Studie

Ferromagnetic Kitaev interaction and the origin of large magnetic anisotropy in α-RuCl3

$\alpha$-RuCl$_3$ is drawing much attention as a promising candidate Kitaev quantum spin liquid. However, despite intensive research efforts, controversy remains about the form of the basic interactions governing the physics of this material. Even the sign of the Kitaev interaction (the bond-dependent anisotropic interaction responsible for Kitaev physics) is still under debate, with conflicting results from theoretical and experimental studies. The significance of the symmetric off-diagonal exchange interaction (referred to as the $\Gamma$ term) is another contentious question. Here, we present resonant elastic x-ray scattering data that provides unambiguous experimental constraints to the two leading terms in the magnetic interaction Hamiltonian. We show that the Kitaev interaction ($K$) is ferromagnetic, and that the $\Gamma$ term is antiferromagnetic and comparable in size to the Kitaev interaction. Our findings also provide a natural explanation for the large anisotropy of the magnetic susceptibility in $\alpha$-RuCl$_3$ as arising from the large $\Gamma$ term. We therefore provide a crucial foundation for understanding the interactions underpinning the exotic magnetic behaviours observed in $\alpha$-RuCl$_3$.Comment: 5 pages, two-column, 3 figure