There is evidence indicating that using the current UK energy feeding system to ration the present sheep flocks may underestimate their nutrient requirements. The objective of the present study was to address this issue by developing updated maintenance energy requirements for the current sheep flocks and evaluating if these requirements were influenced by a range of dietary and animal factors. Data (n = 131) used were collated from five experiments with sheep (5 to 18 months old and 29.0 to 69.8 kg BW) undertaken at the Agri-Food and Biosciences Institute of the UK from 2013 to 2017. The trials were designed to evaluate the effects of dietary type, genotype, physiological stage and sex on nutrient utilization and energetic efficiencies. Energy intake and output data were measured in individual calorimeter chambers. Energy balance (Eg) was calculated as the difference between gross energy intake and a sum of fecal energy, urine energy, methane energy and heat production. Data were analysed using the restricted maximum likelihood analysis to develop the linear relationship between Eg or heat production and metabolizable energy (ME) intake, with the effects of a range of dietary and animal factors removed. The net energy (NEm) and ME (MEm) requirements for maintenance derived from the linear relationship between Eg and ME intake were 0.358 and 0.486 MJ/kg BW0.75, respectively, which are 40% to 53% higher than those recommended in energy feeding systems currently used to ration sheep in the USA and the UK. Further analysis of the current dataset revealed that concentrate supplement, sire type or physiological stage had no significant effect on the derived NEm values. However, female lambs had a significantly higher NEm (0.352 v. 0.306 or 0.288 MJ/kg BW0.75) or MEm (0.507 v. 0.441 or 0.415 MJ/kg BW0.75) than those for male or castrated lambs. The present results indicate that using present energy feeding systems in the UK developed over 40 years ago to ration the current sheep flocks could underestimate maintenance energy requirements. There is an urgent need to update these systems to reflect the higher metabolic rates of the current sheep flocks.

The three-dimensional flow characteristics of the compressible vortex ring generated by under-expanded circular jets with two typical pressure ratios, i.e.  $n=1.4$ (moderate) and 4.0 (high), are investigated numerically with the use of large-eddy simulations. Our results illustrate that these two pressure ratios correspond to different shock structures (shock cell and Mach disc, respectively) within the jet. These two typical types of flow structures and characteristics are discussed and validated with experiments, and the different generation mechanisms of the secondary vortex rings are compared. Moreover, detailed information about the evolution of the secondary vortex ring, primary vortex ring and turbulence transition features, including the radial and azimuthal modes, is investigated. The geometric features and mixing effects of the jets are also explored.

Recent studies have shown that modes of evolution, namely directional trend, random walk, and stasis, vary across morphologic traits and over the geographic range of a taxon. If so, is it possible that our interpretation of evolutionary modes is actually driven by our selection of traits in a study? In an attempt to answer this question, we have restudied the middle Miocene planktonic foraminifera Fohsella lineage, an iconic example of gradual morphologic evolution. In contrast to previous studies that have focused on the gross morphology as embodied by the edge view of tests, we analyze here multiple phenotypic traits chosen because their biologic and ecologic significance is well understood in living populations. We find that traits in the lineage did not evolve in concert. The timing and geographic pattern of changes in shape, coiling direction, size, and ecology were different. The evolution of this lineage is a mosaic combination of different evolutionary modes for different traits. We suggest that overemphasis on the evolution of some single trait, such as the edge-view outline, from narrow geographic ranges has significantly underestimated the dynamic evolutionary history of this group.

The Multiemployer Pension Reform Act (MPRA) allows multiemployer plans facing insolvency to apply for approval from the Treasury to cut accrued benefits of plan members to prolong plan solvency—a departure from the benefit protections of Employee Retirement Income Security Act. To assess the law's impact, this paper models Central States Teamsters – by far the largest – plan to have applied under the new law to reduce benefits. Using a stochastic model of future investment returns, the probability of insolvency within 10 years drops from 50% (without cuts) to 6% (with cuts). While benefit cuts increase the overall welfare of participants by extending the plan's life, the welfare of younger retirees (under age 75) worsens and welfare of workers improves.

Tropical glaciers constitute an important source of water for downstream populations. However, our understanding of glacial melt processes is still limited. One observed process that has not yet been quantified for tropical glaciers is the enhanced melt caused by the longwave emission transfer. Here, we use high-resolution surface temperatures obtained from the thermal infrared imagery of the Cuchillacocha Glacier, in the Cordillera Blanca, Peru in June 2014 to calculate a margin longwave flux. This longwave flux, reaching the glacier margin from the adjacent exposed rock, varies between 81 and 120 W m−2 daily. This flux is incorporated into a physically-based melt model to assess the net radiation budget at the modeled glacier margin. The simulation results show an increase in the energy available for melt by an average of 106 W m−2 during the day when compared with the simulation where the LW margin flux is not accounted for. This value represents an increase in ablation of ~1.7 m at the glacier margin for the duration of the dry season. This study suggests that including the quantification of the glacier margin longwave flux in physically-based melt models results in an improved assessment of tropical glacier energy budget and meltwater generation.

European pig production continues to encounter economic and environmental challenges. To address these issues, methods have been developed to assess performances of pig production systems. Recent studies indicate that considering variability in performances among pigs improves the accuracy and reliability of results compared with modelling an average animal. Our objective was to develop a pig fattening unit model able to (i) simulate individual pig performances, including their variability in interaction with farmers’ practices and management, and (ii) assess their effects on technical, economic and environmental performances. Farmer practices included in the model were chosen from a typology generated from on-farm surveys focused on batch management, pig allocation to pens, pig feeding practices, practices of shipping to the slaughterhouse, and management of the remaining pigs. Pigs are represented using an individual-based model adapted from the InraPorc® model. To illustrate the model’s abilities, four scenarios were simulated that combine two feed rationing plans (ad libitum, restricted to 2.5 kg/day) and two feed sequence plans (two-phase, 10-phase). Analysis of variance was performed on the simulated technical, economic and environmental indicators (calculated via Life Cycle Assessment). The feed rationing plan and feed sequence plan significantly affected all indicators except for the premium per pig, for which the feed sequence plan did not have a significant effect. The ‘restricted 10-phase’ scenario maximised gross margin of the fattening unit (14.2 €/pig) and minimised environmental impacts per kg of pig produced. In contrast, the ‘ad libitum two-phase’ scenario generated the lowest margin (8.20 €/pig) and the highest environmental impacts. The model appears to be a promising tool to assess effects of farmers’ practices, pig characteristics and farm infrastructure on technical, economic and environmental performances of the fattening unit, and to investigate the potential of improvement. However, further work is needed, based on virtual experiments, in order to evaluate the effects of a larger diversity of practices.

Ice flow numerical models are essential for predicting the evolution of ice sheets in a warming climate. Recent research emphasizes the need for higher-order and even full-Stokes flow models, instead of the traditional shallow-ice approximation, whose assumptions are not valid in certain critical areas. These higher-order models are, however, computationally intensive and difficult to use at the continental scale. Here we present a new technique, the Tiling method, to couple ice flow models of varying orders of complexity. The goal of the method is to limit the spatial extent of where higherorder models are applied to reduce the computational cost, while maintaining the model precision. We apply this method on synthetic geometries to demonstrate its practical use. We first use a geometry for which all models yield the same results to check the consistency of the method. Then we apply our method to a geometry for which a full-Stokes model is required in the vicinity of the ice front. Our results show that the hybrid models present significant improvements over mono-model approaches and reduce computational times.

Interferometric radar images collected by ERS-1, ERS-2 and RADAR- SAT-1 are used to observe the rupture tip of rifts that propagate along Hemmen Ice Rise on the Ronne Ice Shelf, Antarctica. Interferograms generated in 1992 and 1997 allow for the observation of ice deformation accumulated over 9 and 24 days respectively. These interferograms are combined, in order to separate the continuous process of creep deformation from the more cyclic motion caused by variations in ocean tide. An examination of local gradients in creep deformation reveals the pattern of ice deformation around and near the rupture tips and rifts with great precision (up to 10 cm a-1). We compare the observations with a deformation model for ice and obtain the following results: (1) The tidal oscillation of the Ronne Ice Shelf only yields small deformations along the rifts and near the rupture tips. (2) Along the ice front, the rifts and at the rupture tips, vertical bending is observed which is well explained by a model of viscous deformation of ice. Furthermore, the model indicates that the deformation pattern observed at the rupture tips is a sensitive indicator of the propagation state of the rifts (i.e. active vs inactive). (3) The viscous adjustment of ice is the dominant mode of deformation, masking the deformation pattern predicted by linear elastic fracture mechanics (LEFM). (4) Yet, at a spatial scale equivalent to the length of a rift, the propagation rate is well predicted by LEFM.

Calcareous nannoplankton diversity varied greatly during the Paleogene. From extremely reduced values (~10 species) in the early Paleocene (circa 66.4 to 66 Ma, age estimates from Berggren, Kent and Flynn, 1985) following the terminal Cretaceous extinctions, diversity increased progressively throughout the late Paleocene and early Eocene and reached a maximum (~120 species) in the early middle Eocene (circa 52–48 Ma). This was followed by a step-like decrease until the early Oligocene (circa 35 Ma) when minimal values (~37 species) were reached once again. After a stable low during the remainder of the early Oligocene, a moderate, increase occurred near the early/late Oligocene boundary (circa 30 Ma).

Temperature has been regarded as the most important factor controlling the distribution of the calcareous nannoplankton following the characterisation of five temperature-controlled assemblages of living Coccolithophoridae in the Atlantic Ocean. Studies relative to variations in diversity in the calcareous nannoplankton throughout the Mesozoic and Cenozoic and among the extinct late Paleocene to Pliocene group Discoaster, and to changing biogeographic patterns during the Cenozoic have revealed an apparent relationship between composition of calcareous nannofossil assemblages and temperature as deduced from isotopic studies. This relationship, which is currently used to infer Paleogene climatic and oceanographic evolution from quantitative analyses of calcareous nannofossil assemblages, is however not a simple one as indicated by the fact that maximum diversity during the Paleogene (i.e., the early middle Eocene) did not occur during (but subsequently to) the warmest time (i.e., the latest Paleocene-earliest Eocene).

Diversity changes in the Paleogene calcareous nannoplankton are strikingly similar to diversity changes in the Paleogene planktonic foraminifera, which have been shown to reflect fluctuations in nutrient availibility as indicated by oxygen and carbon isotopes. The parallel evolution in the two groups thus suggests that trophic levels in the photic zone played an important role in the Paleogene diversification of the calcareous nannoplankton. In the present day ocean, the calcareous nannoplankton (Coccolithophoridae) dominate the phytoplankton under oligotrophic conditions and tropical waters are characterized by highly diversified associations with strong vertical specific stratification. Only few species occur under meso- and eutrophic conditions, and there is no vertical stratification. Extremely low diversity during the earliest Paleocene followed by increasing diversity through the Paleocene and earliest Eocene is interpreted as reflecting the change from an essentially mesotrophic to an oligotrophic ocean, increased rates of speciation resulting from niche partitioning occasioned by increased oligotrophy, leading to strong vertical stratification of species in the photic zone. Decrease in diversity from middle Eocene to early Oligocene reflects, on the other hand, progressive eutrophication of the ocean as a result of climatic deterioration.

The Côa rock art covers 17 km of the river valley and extends along the banks of the Douro, downstream of the confluence between the two rivers. A total of 194 different panels with Palaeolithic zoomorphic motifs have already been identified. Later prehistoric and historic periods, especially the Iron Age, are also represented. Settlement of the valley in Upper Palaeolithic times is documented by residential sites dating to the Gravettian, the Solutrean and the Magdalenian periods. Results of stylistic analysis, whose chronological predictions have been independently confirmed by superposition patterns derived from the figurative stratigraphies observed in the numerous palimpsests known, indicate that all these periods are also represented in the art. The outdoor location of the Palaeolithic art, the size of the territory, the number and aesthetic quality of the motifs represented and the almost uninterrupted continuity to the present of the artistic use of the region's rock faces concur to the uniqueness of this complex of sites. Accordingly, an Archaeological Park was established in the area, the construction of the dam that threatened to flood the rock art has been abandoned and the valley is to be included in UNESCO's World Heritage List.

The origin of the wide range of morphologies observed in planetary nebulae (PNe) is not well established. The influence of a binary companion of the central star can naturally explain this variety of morphologies, but very few PNe have known binary central stars. The evolution of the binary system with mass loss may result in the displacement of the central star from the nebular center. The large sample of PNe observed by HST is being used to search for de-centered central stars. Preliminary results indicate that the occurrence of de-centered central stars is widespread among all morphological types of PNe.

Because the paleontologic concept of Coccolithophoridae species is restricted and far removed from the biologic concept, which itself is not yet satisfactorily established, calcareous nannofossil taxonomy remains in an unsatisfactory state. This situation is clearly reflected by various authors' widely different interpretations of the phylogenetic relationships among species in a given genus and among genera. Examples taken from the extant genus Helicosphaera suggest that because of parallel evolution, delineation of phylogenetic relationships among coccolith morphospecies using morphologic data alone are hazardous, as is delineation of phylogenetic relationships among closely related genera.