Host genetics determine susceptibility to avian influenza infection and transmission dynamics

Host-genetic control of influenza virus infection has been the object of little attention. In this study we determined that two inbred lines of chicken differing in their genetic background, Lines 0 and C-B12, were respectively relatively resistant and susceptible to infection with the low pathogenicity influenza virus A/Turkey/England/647/77 as defined by substantial differences in viral shedding trajectories. Resistant birds, although infected, were unable to transmit virus to contact birds, as ultimately only the presence of a sustained cloacal shedding (and not oropharyngeal shedding) was critical for transmission. Restriction of within-bird transmission of virus occurred in the resistant line, with intra-nares or cloacal infection resulting in only local shedding and failing to transmit fully through the gastro-intestinal-pulmonary tract. Resistance to infection was independent of adaptive immune responses, including the expansion of specific IFNγ secreting cells or production of influenza-specific antibody. Genetic resistance to a novel H9N2 virus was less robust, though significant differences between host genotypes were still clearly evident. The existence of host-genetic determination of the outcome of influenza infection offers tools for the further dissection of this regulation and also for understanding the mechanisms of influenza transmission within and between birds

Form-stable benzoxazine-urethane alloys for thermally reversible light scattering materials

Thermally reversible light scattering (TRLS) materials based solely on benzoxazine-urethane (BA-a/PU) alloys were successfully fabricated and demonstrated in this work. The alloys displayed the opaque state below 40 °C. The alloys were transformed to the transparent state upon exposing to the transition temperature of 60–130 °C, depending on the molecular weights and mass concentrations of urethane prepolymers in the BA-a/PU alloys. The optical state transitions were reversible with small hystereses. BA-a/PU alloys exhibited a good optical contrast with 0%T at the light scattering state and almost 100%T at the transparent state. The alloys were glassy and form-stable up to 250 °C, due to the synergistic behavior in the glass transition temperatures. The reaction-induced phase separation effectuated by the incorporation of urethane prepolymer into thermosetting polybenzoxazine, the sizes and local concentrations of the phase-separated urethane microdomains in the supporting polybenzoxazine matrix, and the reversible dissolution and demixing of urethane microdomains and polybenzoxazine phase played crucial roles on TRLS properties of the developed benzoxazine-urethane alloys

Avian Influenza Virus

Avian influenza is a disease caused by influenza A virus (IAV) that mainly affects domestic poultry but poses a serious zoonotic threat due to direct transmission from poultry to mammals including human beings. While the high pathogenic avian influenza (HPAI) mainly caused by H5 and H7 subtypes of IAVs lead to high mortality, the low pathogenic avian influenza (LPAI) caused by all the 16 haemagglutinin subtypes lead to high production losses. Wild aquatic birds serve as reservoir hosts as the virus cause productive subclinical infections in them. Reported for the first time in 1878 in Italy, the IAVs have so far caused three pandemics in humans. The H5N1 virus currently circulating for over two decades throughout the world has caused outbreaks in over 60 countries including India. LPAI viruses are transmitted amongst terrestrial poultry via respiratory droplets and aerosols and the HPAI viruses are transmitted via faecal route. Pathogenesis of IAVs is markedly different between wild water birds, terrestrial poultry and humans. Clinical diagnosis of AI is very difficult and often confused with other respiratory diseases of poultry. Diagnosis of AI involves isolation, identification and characterization of the virus. Current molecular techniques particularly the RT-PCR and real-time RT-PCR are recommended for rapid AI diagnosis. Effective control programs for avian influenza in poultry farms or its spread between farms can reduce the loss due to the disease by a minimum of 75%. The various control measures along with their advantages and disadvantages are discussed in detail in this chapter