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PurposeThe COVID PROFILE cohort is a longitudinal clinical study based in Victoria Australia, which was established to understand immunity to SARS-CoV-2 in alow transmission population settingand to identify immunological markers of long-term immunity and immune-dysregulation after both infection and vaccination. Additionally, this cohort was established as a biobank resource for researchers to address other health-related immunological questions.ParticipantsWe enrolled 178 adult community members, including household contacts, who had either recovered from a SARS-CoV-2 infection or were SARS-CoV-2 naïve. Only participants ≥18 years of age and, in the case of female participants, non-pregnant women at the time of enrollment were included in the study. Detailed COVID-19 clinical data, vaccination status, medical history and demographics was collected.Findings to dateAt enrollment, we found that 87.8% of COVID-19 recovered individuals were seropositive with detectable levels of anti-SARS-CoV-2 IgG antibodies. Seronegative COVID-19 recovered individuals included asymptomatic individuals or participants that were enrolled more than 12 months after their COVID-19 diagnosis. Except for one individual who was seropositive at baseline despite a previous SARS-CoV-2 PCR negative diagnosis, all household contacts and other community members enrolled as SARS-CoV-2 PCR negative, were seronegative for all SARS-CoV-2-specific antibodies tested. The infection rate (re-infection or new infection) during 24 months of the study was 42.7%, as determined by either rapid antigen tests, PCRs or serology screens. Of the SARS-CoV-2 recovered participants, 32.6% reported ongoing symptoms at enrollment of which 47% had already experienced ongoing symptoms for more than 12 weeks.Future PlansCOVID PROFILE will be used to comprehensively understand temporal immunity to SARS-CoV-2 and COVID-19 vaccines and to understand the impact of host immunological composition on such immunity and symptom severity. Additionally, studies focusing on understanding immunity following breakthrough infections and immunological risk factors that contribute towards development of long COVID are planned.Limitations/Strengths of the studyExtensive clinical information is available and longitudinal samples (blood, saliva and oropharyngeal swabs) collected at regular intervals up to 2.5 years after initial enrolment.This low SARS-CoV-2 transmission population cohort, enables exploration of difference in both the acquisition and maintenance of naturally acquired and vaccine-induced immunity not confounded by prior, frequent and/or undetected exposures.Extensive biobank of numerous blood fractions and biospecimen enables further exploration of mucosal immunity, nasal microbiome and humoral and cellular immunity over time.The cohort may be limited in addressing research questions regarding outcomes and risk factors and their associations where low incidence is expected.

Since the emergence of SARS-CoV-2 (COVID-19), there have been multiple waves of infection and multiple rounds of vaccination rollouts. Both prior infection and vaccination can prevent future infection and reduce severity of outcomes, combining to form hybrid immunity against COVID-19 at the individual and population level. Here, we explore how different combinations of hybrid immunity affect the size and severity of near-future Omicron waves. To investigate the role of hybrid immunity, we use an agent-based model of COVID-19 transmission with waning immunity to simulate outbreaks in populations with varied past attack rates and past vaccine coverages, basing the demographics and past histories on the World Health Organization (WHO) Western Pacific Region (WPR). We find that if the past infection immunity is high but vaccination levels are low, then the secondary outbreak with the same variant can occur within a few months after the first outbreak; meanwhile, high vaccination levels can suppress near-term outbreaks and delay the second wave. Additionally, hybrid immunity has limited impact on future COVID-19 waves with immune-escape variants. Enhanced understanding of the interplay between infection and vaccine exposure can aid anticipation of future epidemic activity due to current and emergent variants, including the likely impact of responsive vaccine interventions.

The MethaneSAT satellite mission aims at quantifying anthropogenic methane emissions by measuring reflected solar radiation in two spectral windows in the short wave infrared range. In the 1,249 nm - 1,305 nm spectral range the sensor will measure the oxygen (O2) singlet Delta band with a full width at half maximum (FWHM) of 0.17 nm. Additionally, the instrument will observe most of the 2ν3 absorption band of methane (CH4) and the P-branch of a 3ν1+ν3 carbon dioxide (CO2) band in the spectral range 1,605 nm - 1,683 nm at a spectral resolution of 0.23 nm at FWHM. Clouds and aerosols can introduce biases into the inversion of methane column concentrations from solar backscatter measurements and we therefore develop retrieval processors to filter out contaminated scenes.One processor makes use of surface pressure retrievals to infer the presence of scattering particles in the field of view of the sensor. These retrievals specifically take into account O2 airglow emission following the approach of Sun et al. (2018). Surface pressure is retrieved by fitting spectra in the O2 band, assuming a non-scattering atmosphere. We study thresholds in the variations between retrieved surface pressure and a priori meteorological databases which are suitable to screen for clouds and aerosols. A complementary algorithm takes advantage of differences in the atmospheric light path between the two spectral windows of MethaneSAT in the presence of aerosols and clouds. Here, we retrieve water vapor (H2O) column concentrations from the 1.3 µm and 1.6 µm windows under the assumption of the geometric lightpath. The ratio of the H2O retrievals from the two windows is used to construct a filter for aerosol and cloud contaminated scenes. We simulate MethaneSAT measurements with various cloud and aerosol loads to derive the retrieval configurations with highest sensitivity to scattering events.Both filtering approaches are applied to measurements of the MethaneAIR instrument (Staebell et al., 2021) to demonstrate their capacity in screening for clear scenes. Finally, we discuss our on-going efforts in developing a filter for observations affected by cloud shadows. ReferencesStaebell, C., Sun, K., Samra, J., Franklin, J., Chan Miller, C., Liu, X., Conway, E., Chance, K., Milligan, S., and Wofsy, S.: Spectral calibration of the MethaneAIR instrument, Atmospheric Measurement Techniques, 14, 3737–3753, https://doi.org/10.5194/amt-14-3737-2021, 2021.Sun, K., Gordon, I. E., Sioris, C. E., Liu, X., Chance, K., and Wofsy, S. C.: Reevaluating the use of O2 a1Δg band in spaceborne remote sensing of greenhouse gases, Geophysical Research Letters, 45, 5779–5787, https://doi.org/10.1029/2018GL077823, 2018.

We report the results of the trajectory-based simulation of far-infrared collision-induced absorption (CIA) due to CH$_4-$N$_2$ pairs at temperatures between 70 and 400 K. Our analysis utilizes recently calculated high-level potential energy (PES) and induced dipole surfaces (IDS) [Finenko, A. A., Chistikov, D. N., Kalugina, Y. N., Conway E. K., Gordon, I. E., Phys. Chem. Chem. Phys., 2021, doi: 10.1039/d1cp02161c]. Treating collision partners as rigid rotors, the time evolution of interaction-induced dipole is accumulated over a vast ensemble of classical trajectories and subsequently transformed into CIA spectrum via Fourier transform. In our calculations, both bound and unbound states are properly accounted for, and the rigorous theory of lower-order spectral moments is addressed to check the accuracy of simulated profiles. Classically derived trajectory-based profiles are subject to two approximate desymmetrization procedures so that resulting profiles conform to the quantum principle of detailed balance. The simulated profiles are compared to laboratory measurements and employed for modeling Titan's spectra in the 50-500 cm$^{-1}$ range. Based on the desymmetrized simulated profiles, a new semi-empirical model for CH$_4-$N$_2$ CIA is proposed for modeling Titan's infrared spectra. Synthetic spectra derived using this model yield an excellent agreement with the data recorded by the Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft at low and high emission angles.

The study of transport of ionic species through a nanopore is important in determining the underlying behavior of electrolytes on the nanoscale; the understanding of which has important application...

The HITRAN database is an integral component of numerous atmospheric radiative transfer models and it is therefore essential that the database contains the most appropriate up-to-date spectroscopic parameters. To this end, the HITRAN2020 database is scheduled to be released at the end of this year. The compilation of this edition (as is the tradition for the HITRAN database) exemplifies the efficiency and necessity of worldwide scientific collaborations. It is a titanic effort of experimentalists, theoreticians and atmospheric scientists, who measure, calculate and validate the HITRAN data.The HITRAN line-by-line lists for almost all 49 molecules have been updated in comparison to HITRAN2016 (Gordon et al., 2017), the previous compilation. The extent of these updates depend on the molecule, but range from small adjustments for a few lines of an individual molecule to complete replacements of line lists and the introduction of new isotopologues. Many new vibrational bands have been added to the database, thereby extending the spectral coverage and completeness of the datasets. In addition the accuracy of the parameters for major atmospheric absorbers has been substantially increased, often featuring sub-percent uncertainties.Furthermore, the amount of parameters has also been significantly increased. For example, HITRAN2020 will now incorporate non-Voigt line profiles for many gases, broadening by water vapour (Tan et al., 2019), as well as updated collision induced absorption sets (Karman et al., 2019). The HITRAN2020 edition will continue taking advantage of the new structure and interface available at www.hitran.org (Hill et al., 2016) and the HITRAN Application Programming Interface (Kochanov et al., 2016).This talk will provide a summary of these updates, emphasizing details of some of the most important or drastic improvements.References:Gordon, I.E., .et al., (2017), JQSRT 203, 3–69. (doi:10.1016/j.jqsrt.2017.06.038)Hill, C., et al., (2016), JQSRT 177, 4–14. (doi:10.1016/j.jqsrt.2015.12.012)Karman, T., et al. (2019), Icarus 328, 160–175. (doi:10.1016/j.icarus.2019.02.034)Kochanov, R.V., et al.,( 2016), JQSRT 177, 15–30. (doi:10.1016/j.jqsrt.2016.03.005)Tan, Y., et al., (2019), J. Geophys. Res. Atmos. 124, 11580-11594. (doi:10.1029/2019JD030929)

The mathematical modelling of deformable, permeable screen doors was explored to assess their behaviour under wind loading. A load-response model was proposed whereby the wind load was modelled using a simplified approach that allowed it to be approximated as a uniformly distributed pressure load with empirical modification factors applied to relate it to the real case of a door on a building. Several approaches were adopted to model the mechanical behaviour of the door system in response to load, including discrete models based on mass-spring systems, continuum models based on the membrane equations (including tension modulation in some cases), and computational models using finite element packages. The primary aim of the work was to determine the distribution of wind load to the door's supporting `tabs' and estimate a failure wind speed. The mass-spring model and the membrane models without tension modulation both generated unrealistic deflection magnitudes in response to wind load, but could be calibrated in future work, and then used to obtain an estimate of the total force on the tabs. A tension-modulated version of the membrane model performed better with regards to deflected shape and magnitude, but time constraints meant that the load on the tabs was not calculated. Preliminary validation experiments were undertaken and deflected shape and magnitude were successfully measured in response to given wind speeds. References Standards Australia. AS/NZS1170.2–-Structural design actions part 2: Wind actions , 2011. F. Avanzini and R. Maronga. A modular physically based approach to the sound synthesis of membrane percussion instruments. IEEE Transactions on Audio, Speech, and Language Processing , 18(4):891–902, 2010. doi:10.1109/TASL.2009.2036903 B. Bank. Energy-based synthesis of tension modulation in strings. In Proceedings of the 12th International Conference on Digital Audio Effects (DAFx-09) , 2009. http://dafx09.como.polimi.it/proceedings/papers/paper_76.pdf Bert Blocken. 50 years of computational wind engineering: Past, present and future. Journal of Wind Engineering and Industrial Aerodynamics , 129(0):69–102, 2014. doi:10.1016/j.jweia.2014.03.008 Demetres Briassoulis, Antonis Mistriotis, and Anastasios Giannoulis. Wind forces on porous elevated panels. Journal of Wind Engineering and Industrial Aerodynamics , 98(12):919–928, 2010. doi:10.1016/j.jweia.2010.09.006 John Cheung and William Melbourne. Wind loading on porous cladding. In 9th Australasian fluid mechanics conference , 1986. http://people.eng.unimelb.edu.au/imarusic/proceedings/9/CheungMelbourne.pdf John Holmes. Wind Loading of Structures . Spon Press, 2001. P. D. Howell, G. Kozyreff, and J. R. Ockendon. Applied Solid Mechanics . Cambridge University Press, 2009. C.W Letchford. Wind loads on rectangular signboards and hoardings. Journal of Wind Engineering and Industrial Aerodynamics , 89(2):135–151, 2001. doi:10.1016/S0167-6105(00)00068-4 Wojciech Okrasinski and \T1\L ukasz Plociniczak. A nonlinear mathematical model of the corneal shape. Nonlinear Analysis: Real World Applications , 13(3):1498–1505, 2012. doi:10.1016/j.nonrwa.2011.11.014 D. W. Oplinger. Frequency response of a nonlienar stretched string. Journal of the Acoustical Society of America , 32(12):1529–1538, 1960. doi:10.1121/1.1907948 Xavier Provot. Deformation constraints in a mass-spring model to describe rigid cloth behaviour. In Graphics interface , pages 147–147. Canadian Information Processing Society, 1995. http://kucg.korea.ac.kr/education/2005/CSCE352/paper/provot95.pdf P.J Richards and M Robinson. Wind loads on porous structures. Journal of Wind Engineering and Industrial Aerodynamics , 83(13):455–465, 1999. doi:10.1016/S0167-6105(99)00093-8 A.P. Robertson, Ph. Roux, J. Gratraud, G. Scarascia, S. Castellano, M. Dufresne de Virel, and P. Palier. Wind pressures on permeably and impermeably-clad structures. Journal of Wind Engineering and Industrial Aerodynamics , 90(45):461–474, 2002. Bluff Body Aerodynamics and Applications. doi:10.1016/S0167-6105(01)00210-0 T. Tolonen, V. Valimaki, and M. Karjalainen. Modeling of tension modulation nonlinearity in plucked strings. IEEE Transactions on Speech and Audio Processing , 8(3):300–310, 2000. doi:10.1109/89.841212