The diversity of influenza A viruses (IAV) is primarily hosted by two highly divergent avian orders: Anseriformes (ducks, swans and geese) and Charadriiformes (gulls, terns and shorebirds). Studies of IAV have historically focused on Anseriformes, specifically dabbling ducks, overlooking the diversity of hosts in nature, including gull and goose species that have successfully adapted to human habitats. This study sought to address this imbalance by characterizing spillover dynamics and global transmission patterns of IAV over 10 years at greater taxonomic resolution than previously considered. Furthermore, the circulation of viral subtypes in birds that are either host-adapted (low pathogenic H13, H16) or host-generalist (highly pathogenic avian influenza—HPAI H5) provided a unique opportunity to test and extend models of viral evolution. Using Bayesian phylodynamic modelling we uncovered a complex transmission network that relied on ecologically divergent bird hosts. The generalist subtype, HPAI H5 was driven largely by wild geese and swans that acted as a source for wild ducks, gulls, land birds, and domestic geese. Gulls were responsible for moving HPAI H5 more rapidly than any other host, a finding that may reflect their long-distance, pelagic movements and their immuno-naïve status against this subtype. Wild ducks, long viewed as primary hosts for spillover, occupied an optimal space for viral transmission, contributing to geographic expansion and rapid dispersal of HPAI H5. Evidence of inter-hemispheric dispersal via both the Pacific and Atlantic Rims was detected, supporting surveillance at high latitudes along continental margins to achieve early detection. Both neutral (geographic expansion) and non-neutral (antigenic selection) evolutionary processes were found to shape subtype evolution which manifested as unique geographic hotspots for each subtype at the global scale. This study reveals how a diversity of avian hosts contribute to viral spread and spillover with the potential to improve surveillance in an era of rapid global change.

Ammonium sulphate fractionation of barley extracts prepared under conditions which obviate enzyme action allows the preparation of a laevorotatory glucosan uncontaminated by pentosan and of a number of pentosan-rich fractions (contami nated by glucosan). The properties of the pentosan materials are consistent with their being mixtures of xylan, araboxylan and araban each at varying degrees of molecular complexity and of solubility. Malting leads to the substantial elimination of the laevorotatory glucosan, but increases somewhat the recoverable yields of highmolecular pentosan, increase being particularly marked with arabinose-based units. The enzymic changes involved in malting lead to a decrease in viscosity of aqueous solutions of the gums, to increased water solubility, and to a conversion of the isolated gums from a fibrous to a pulverulent condition. Both barley and malt contain galactan, but mannan has been detected in barley only.

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Gulls are ubiquitous in urban areas due to a growing reliance on anthropogenic feeding sites, which has led to changes in their abundance, distribution, and migration ecology, with implications for disease transmission. Gulls offer a valuable model for testing hypotheses regarding the dynamics of influenza A virus (IAV) – for which gulls are a natural reservoir in urban areas. We sampled sympatric populations of Ring‐billed (Larus delawarensis), Herring (L. argentatus), and Great Black‐backed Gulls (L. marinus) along the densely populated Atlantic rim of North America to understand how IAV transmission is influenced by drivers such as annual cycle, host species, age, habitat type, and their interplay. We found that horizontal transmission, rather than vertical transmission, played an outsized role in the amplification of IAV due to the convergence of gulls from different breeding grounds and age classes. We detected overlapping effects of age and season in our prevalence model, identifying juveniles during autumn as the primary drivers of the seasonal epidemic in gulls. Gulls accumulated immunity over their lifespan, however short‐term fluctuations in seroprevalence were observed, suggesting that migration may impose limits on the immune system to maintain circulating antibodies. We found that gulls in coastal urban habitats had higher viral prevalence than gulls captured inland, correlating with higher richness of waterbird species along the coast, a mechanism supported by our movement data. The peak in viral prevalence in newly fledged gulls that are capable of long‐distance movement has important implications for the spread of pathogens to novel hosts during the migratory season as well as for human health as gulls increasingly utilize urban habitats.

Comparative studies of the gross yields of unfractionated water-soluble gum-like materials from a number of cereals indicate that barley Is probably the best source of laevorotatory glucosan and rye the best source of pentosan; wheat occupies an intermediate position, but oats and maize are poor sources of pentosan. In the case of some raw materials, and of adjuncts whose manufacture has involved heat or mechanical treatment, the gum-like materials are strongly contaminated with water-