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Spire Global, Inc. operates a growing fleet of currently more than 100 CubeSats in different low Earth orbits for commercial Earth observation. These satellites are equipped with dual-frequency GPS receivers and an attitude determination and control system, allowing for precise orbit determination. For three different satellites and a time span of six months we analyze the performance and quality of the on-board collected GPS and attitude data and employ it for precise orbit determination using the Bernese GNSS Software and Napeos, two independent state-of-the-art GNSS processing software packages. We describe technical details crucial for POD and present and compare the in-flight calibrated phase center variation maps. Reduced-dynamic and kinematic orbits are then inter-compared between the two software packages as well as to the orbit solutions produced by Spire Global. We report pseudo-range and carrier phase residuals at the level of 3–4 m and 8–9 mm RMS and a good agreement between the reduced-dynamic and kinematic orbits of around 5 cm 3D RMS. The reduced-dynamic orbit positions and velocities produced with the two employed software packages agree in average on the level of 6–7 cm and 0.05–0.07 mm/s 3D RMS, while the comparison to the orbits produced by Spire Global is markedly worse with 27–30 cm and 0.32–0.36 mm/s 3D RMS. The presented results are an encouraging first step towards using GPS data from the Spire constellation for geodetic, geophysical and ionospheric applications. [ABSTRACT FROM AUTHOR]

The aerodynamic interaction between the wake flow structure behind a single spire with a smooth wall boundary layer at a long streamwise location was observed in a wind tunnel experiment. The application of a single spire is intended to generate a wake flow similar to the one generated behind a skyscraper. A quarter elliptic wedge spire was used and a long streamwise distance of up to 26 times the spire's height was adopted to ensure the development of the boundary layer and the wake recovery. To grasp how the smooth wall boundary layer interacts with the wake as well as how the wake recovers downstream, vertical and lateral velocity profiles were examined. Despite only one spire being utilized, it was found that the role of the spire as a vortex generator was confirmed the boundary layer height in the with-spire case increased compared to that of the without-spire case. Moreover, the velocity deficit recovery process was observed vertically and streamwise. However, within the boundary layer, the recovery rate in the streamwise direction was lower compared to the above it. This finding indicates that within the boundary, the turbulence generated can sustain the wake caused by the spire, reducing the recovery rate. Based on the current lateral velocity analysis, the final streamwise distance required by the wake to fully recover could not be predicted due to the large velocity deviation of 2.15% at the end of the streamwise distance. [ABSTRACT FROM AUTHOR]

The aerodynamic interaction between the wake flow structure behind a single spire with a smooth wall boundary layer at a long streamwise location was observed in a wind tunnel experiment. The application of a single spire is intended to generate a wake flow similar to the one generated behind a skyscraper. A quarter elliptic wedge spire was used and a long streamwise distance of up to 26 times the spire’s height was adopted to ensure the development of the boundary layer and the wake recovery. To grasp how the smooth wall boundary layer interacts with the wake as well as how the wake recovers downstream, vertical and lateral velocity profiles were examined. Despite only one spire being utilized, it was found that the role of the spire as a vortex generator was confirmed the boundary layer height in the with-spire case increased compared to that of the without-spire case. Moreover, the velocity deficit recovery process was observed vertically and streamwise. However, within the boundary layer, the recovery rate in the streamwise direction was lower compared to the above it. This finding indicates that within the boundary, the turbulence generated can sustain the wake caused by the spire, reducing the recovery rate. Based on the current lateral velocity analysis, the final streamwise distance required by the wake to fully recover could not be predicted due to the large velocity deviation of 2.15% at the end of the streamwise distance.

In this study, we investigate the performances of a commercial Global Navigation Satellite System (GNSS) Radio Occultation (RO) mission and a new-generation RO constellation, i.e., Spire and Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC-2), respectively. In the statistical comparison between Spire and COSMIC-2, the results indicate that although the average signal-to-noise ratio (SNR) of Spire is far weaker than that of COSMIC-2, the penetration of Spire is comparable to, and occasionally even better than, that of COSMIC-2. In our analysis, we find that the penetration depth is contingent upon various factors including SNR, GNSS, RO modes, topography, and latitude. With the reanalysis of the European Centre for Medium-Range Weather Forecasts and Radiosonde as the reference data, the identical error characteristics of Spire and COSMIC-2 reveal that overall, the accuracy of Spire's neutral-atmosphere data products was found to be comparable to that of COSMIC-2. [ABSTRACT FROM AUTHOR]

Global Navigation Satellite System (GNSS) Radio Occultation (RO) data play an essential role in improving numerical weather prediction (NWP) and monitoring climate change. The NOAA Commercial RO Purchase Program (CDP) purchased RO data provided by Spire Global Inc. To ensure the data quality from Spire Global Inc. is consistent with other RO missions, we need to quantify their accuracy and retrieval uncertainty carefully. In this work, Spire Wet Profile (wet temperature profile) data from 7 September 2021 to 31 October 2022, processed by the University Corporation for Atmospheric Research (UCAR), and COSMIC-2 (Constellation Observing System for Meteorology, Ionosphere, and Climate-2/Formosa Satellite Mission 7) data are evaluated through comparison with NOAA-20 Advanced Technology Microwave Sounder (ATMS) microwave sounder measurements and collocated RS41 radiosonde measurements. Through the Community Radiative Transfer Model (CRTM) simulation, we convert the Spire and COSMIC-2 RO retrievals to ATMS brightness temperature (BT) at sounding channels CH07 to CH14 (temperature channels), with weighting function peak heights from 8 km to 35 km, and CH19 to CH22 (water vapor channels), with weighting function peak heights ranging from 3.2 km to 6.7 km, and compare the simulations with the collocated NOAA-20 ATMS measurements over ocean. Using ATMS observations as references, Spire and COSMIC-2 BTs agree well with ATMS within 0.07 K for CH07-14 and 0.20 K for CH19-22. The trends between Spire and COSMIC-2 are consistent within 0.07 K/year over the oceans for ATMS CH07-CH13 and CH19-22, indicating that Spire/COSMIC-2 wet profiles are, in general, compatible with each other over oceans. The RO retrievals and RS41 radiosonde observation (RAOB) comparison shows that above 0.2 km altitude, RS41 RAOB matches Spire/COSMIC-2 temperature profiles well with a temperature difference of <0.13 K, and the trends between Spire and COSMIC-2 are consistent within 0.08 K/year over land, indicating that Spire/COSMIC-2 wet profiles are overall compatible with each other through RS41 RAOB measurements over land. In addition, the consistency of Spire and COSMIC-2 based on different latitude intervals, local times, and signal-to-noise ratios (SNRs) through ATMS was evaluated. The results show that the performance of Spire is comparable to COSMIC-2, even though COSMIC-2 has a higher SNR. The high quality of RO profiles from Spire is expected to improve short- and medium-range global numerical weather predictions and help construct consistent climate temperature records. [ABSTRACT FROM AUTHOR]

This paper investigates the use of solar thermal energy systems in SPIRE (sustainable process industry through resource and energy efficiency) and non-SPIRE industries and evaluates the use a novel solar Fresnel collector for generating temperatures of up to 400 °C. The investigation showed that solar thermal energy systems were mostly integrated into the non-SPIRE industries like food and beverages, paper and pulp and the textile industries with temperature requirements of up to 150 °C while few of them were used in the SPIRE industries like the non-metallic minerals, chemicals, basic metals and water industries with temperature requirements of up to 1500 °C. The limitation of those solar energy systems was seen in their application in higher irradiance regions due to the limited operation temperature of certain types of solar collectors, which particularly affected the SPIRE industry sector. To increase their use in high and low irradiance regions, a novel solar thermal system developed by the EU-ASTEP project that could achieve a temperature of up to 400 °C was introduced. The calculations of the theoretical and technical potential application of the ASTEP system in EU industrial processes showed an increase of 43%, of which 802.6 TWh totalled the theoretical potential and 96.3 TWh the technical potential. This resulted in a reduction of greenhouse gas (GHG) emissions by 24 thousand kt CO2 equivalent, which could help industries to achieve their 2050 targets for net-zero GHG emissions. [ABSTRACT FROM AUTHOR]

Looking back at two decades of research on SPIRE actin nucleator proteins, the first decade was clearly dominated by the discovery of SPIRE proteins as founding members of the novel WH2-domainbased actin nucleators, which initiate actin filament assembly through multiple WH2 actin-binding domains. Through complex formation with formins and class 5 myosins, SPIRE proteins coordinate actin filament assembly and myosin motor-dependent force generation. The discovery of SPIRE-regulated cytoplasmic actin filament meshworks in oocytes initiated the next phase of SPIRE research, which has found that SPIRE proteins are integrated in a diverse range of cell biological processes. In addition to regulating vesicle-based actin filament meshworks, SPIRE proteins function in the organisation of actin structures driving the inward movement of pronuclei of the mouse zygote. Localisation at cortical ring structures and the results of knockdown experiments indicate that SPIRE proteins function in the formation of meiotic cleavage sites in mammalian oocytes and the externalisation of von Willebrand factor from endothelial cells. Alternative splicing targets mammalian SPIRE1 towards mitochondria, where it has a role in fission. In this Review, we summarise the past two decades of SPIRE research by addressing the biochemical and cell biological functions of SPIRE proteins in mammalian reproduction, skin pigmentation and wound healing, as well as in mitochondrial dynamics and host-pathogen interactions. [ABSTRACT FROM AUTHOR]

To investigate the pollutant dispersion of a nuclear power plant, a field tracing experiment was carried out in neutral stratification weather with the main wind direction SSW. On this basis, a wind speed profile and turbulence intensity profile consistent with the site were created in the wind tunnel. Meanwhile, how to generate a wind field of neutral stratification in a wind tunnel was studied in detail. Finally, a 1:1000 nuclear power area model was made to conduct tracing experiments in the wind tunnel. The results show that when the horizontal and vertical distances of the spire are 300 mm and 500 mm, and the horizontal and vertical distances of the rough element are 250 mm and 500 mm. A wind speed profile with a wind profile index of 0.321 was generated in the wind tunnel (0.334 in the field test), and the wind tunnel tracer experiment had the same diffusion trend as the field, which verified the accuracy of the flow field. [ABSTRACT FROM AUTHOR]

In this study, we investigate the performances of a commercial Global Navigation Satellite System (GNSS) Radio Occultation (RO) mission and a new-generation RO constellation, i.e., Spire and Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC-2), respectively. In the statistical comparison between Spire and COSMIC-2, the results indicate that although the average signal-to-noise ratio (SNR) of Spire is far weaker than that of COSMIC-2, the penetration of Spire is comparable to, and occasionally even better than, that of COSMIC-2. In our analysis, we find that the penetration depth is contingent upon various factors including SNR, GNSS, RO modes, topography, and latitude. With the reanalysis of the European Centre for Medium-Range Weather Forecasts and Radiosonde as the reference data, the identical error characteristics of Spire and COSMIC-2 reveal that overall, the accuracy of Spire’s neutral-atmosphere data products was found to be comparable to that of COSMIC-2.

Global Navigation Satellite System (GNSS) Radio Occultation (RO) data play an essential role in improving numerical weather prediction (NWP) and monitoring climate change. The NOAA Commercial RO Purchase Program (CDP) purchased RO data provided by Spire Global Inc. To ensure the data quality from Spire Global Inc. is consistent with other RO missions, we need to quantify their accuracy and retrieval uncertainty carefully. In this work, Spire Wet Profile (wet temperature profile) data from 7 September 2021 to 31 October 2022, processed by the University Corporation for Atmospheric Research (UCAR), and COSMIC-2 (Constellation Observing System for Meteorology, Ionosphere, and Climate-2/Formosa Satellite Mission 7) data are evaluated through comparison with NOAA-20 Advanced Technology Microwave Sounder (ATMS) microwave sounder measurements and collocated RS41 radiosonde measurements. Through the Community Radiative Transfer Model (CRTM) simulation, we convert the Spire and COSMIC-2 RO retrievals to ATMS brightness temperature (BT) at sounding channels CH07 to CH14 (temperature channels), with weighting function peak heights from 8 km to 35 km, and CH19 to CH22 (water vapor channels), with weighting function peak heights ranging from 3.2 km to 6.7 km, and compare the simulations with the collocated NOAA-20 ATMS measurements over ocean. Using ATMS observations as references, Spire and COSMIC-2 BTs agree well with ATMS within 0.07 K for CH07-14 and 0.20 K for CH19-22. The trends between Spire and COSMIC-2 are consistent within 0.07 K/year over the oceans for ATMS CH07-CH13 and CH19-22, indicating that Spire/COSMIC-2 wet profiles are, in general, compatible with each other over oceans. The RO retrievals and RS41 radiosonde observation (RAOB) comparison shows that above 0.2 km altitude, RS41 RAOB matches Spire/COSMIC-2 temperature profiles well with a temperature difference of

To investigate the pollutant dispersion of a nuclear power plant, a field tracing experiment was carried out in neutral stratification weather with the main wind direction SSW. On this basis, a wind speed profile and turbulence intensity profile consistent with the site were created in the wind tunnel. Meanwhile, how to generate a wind field of neutral stratification in a wind tunnel was studied in detail. Finally, a 1:1000 nuclear power area model was made to conduct tracing experiments in the wind tunnel. The results show that when the horizontal and vertical distances of the spire are 300 mm and 500 mm, and the horizontal and vertical distances of the rough element are 250 mm and 500 mm. A wind speed profile with a wind profile index of 0.321 was generated in the wind tunnel (0.334 in the field test), and the wind tunnel tracer experiment had the same diffusion trend as the field, which verified the accuracy of the flow field.

Multiple radio occultation (RO) missions are currently providing observations that are assimilated by the world’s leading numerical weather prediction centers. These RO missions use the same signals originating from the Global Navigation Satellite Systems (GNSS), but they have different satellite designs and sizes with different antennas and receivers. This results in different noise levels for different missions. Although the amplitude data are characterized by the Signal-to-Noise Ratio (SNR), the noise, to which they are normalized, is not the real Noise Floor (NF) of the RO observations. We study the statistical distributions of the SNR and NF for RO missions including COSMIC, COSMIC2, METOP-A, METOP-B, METOP-C, and Spire. We demonstrate that different missions have different NF values and different NF and SNR distributions, sometimes multimodal. We propose to use the most probable NF value as an SNR normalization constant in order to compare the SNR values from different RO missions.

The residents of Dublin, Ireland have developed a robust commemorative infrastructure throughout the city since the early eighteenth century. A prominent site in this landscape is at the centre of O'Connell Street (Sackville Street from the late 1700s to 1924). Today, the Spire of Dublin (2003) is located at this site. But it projects an ambiguous connection to both the city's and the country's factious history. Two other statues previously stood on the site, both commemorating British imperial military figures: the Blakeney Monument (1759) and Nelson's Pillar (1808). Both works were intentionally destroyed in acts of urban iconoclasm. An analysis of the changes in the monumental public art on this site over the centuries demonstrates that iconoclasm has been a factor in shifting Irish attitudes toward the British and themselves, Irish associations with power and memory, and a potent symbol in Dublin's urban landscape. This is established by using an expanded conceptualisation of iconoclasm that incorporates a series of post-fall responses to a monument and its site's physical state and context over time, the site's continued symbolic meanings, and the site becoming home to new monumental or other symbolic expressions. The result illustrates that this site has been significantly inscribed into British imperial and Irish national iconography regardless of the monument or public sculpture it has held. [ABSTRACT FROM AUTHOR]

The study of eukaryotic extremophiles is relatively novel, and, therefore, documentation of the structure and function of micro-organisms in continental hydrothermal systems globally is limited. In this study, we investigate fossil diatoms in siliceous hydrothermal deposits of the Upper Geyser and Yellowstone Lake hydrothermal basins in Yellowstone National Park, and utilize preserved diatom assemblages to infer local environmental conditions. Siliceous sinter from both the Upper Geyser Basin and Yellowstone Lake contains evidence of in-situ diatom growth within these environments. At Upper Geyser Basin, the assemblage consisted of species that could grow on moist siliceous sinter and was dominated by Rhopalodia gibberula. Diatom valves were found in various preservation states, ranging from nearly pristine to highly diagenetically altered. Diatoms collected from siliceous spires in Yellowstone Lake consisted largely of tychoplanktonic and benthic species that were almost certainly growing on the outside of the structure, with an assemblage indicative of relatively shallow, alkaline waters. What remains unclear without access to material for high-resolution dating is whether diatoms colonized the spires during hydrothermal activity or after activity ceased. Our results indicate that diatom frustules can, to some extent, survive alteration in low-temperature (<76°C) hydrothermal environments. [ABSTRACT FROM AUTHOR]

GPS-Radio Occultation (GPS-RO), and generally, Global Navigation Satellite System Radio Occultation (GNSS-RO), is a technique that measures the refractivity of the Earth's atmosphere as a Low Earth Orbit (LEO) satellite listens to the radio signal of a GNSS satellite. As the signal between the two satellites travels through the different levels of the Earth's atmosphere, temperature and water vapor content can be derived at each occultation point, allowing for a new weather dataset to be available to meteorologists. In this article we describe the benefits of large-scale GNSS-Radio Occultation (GNSS-RO) as a method of gathering large amounts of extremely accurate atmospheric data that exceptionally contributes to the performance of advanced numerical weather prediction (NWP) models.

GPS-Radio Occultation (GPS-RO), and generally, Global Navigation Satellite System Radio Occultation (GNSS-RO), is a technique that measures the refractivity of the Earth's atmosphere as a Low Earth Orbit (LEO) satellite listens to the radio signal of a GNSS satellite. As the signal between the two satellites travels through the different levels of the Earth's atmosphere, temperature and water vapor content can be derived at each occultation point, allowing for a new weather dataset to be available to meteorologists. In this article we describe the benefits of large-scale GNSS-Radio Occultation (GNSS-RO) as a method of gathering large amounts of extremely accurate atmospheric data that exceptionally contributes to the performance of advanced numerical weather prediction (NWP) models. [ABSTRACT FROM AUTHOR]

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We can imagine many of our emotions in our family pet: hunger, fear, anger, lust, and even the bonding that we call love. But not the appreciation of a sunset, sonnet, musical passage, or good joke. Mechner takes on the gamut of such aesthetic appreciations, removed from the urgency of the primal ones, and gives us the first thorough attempt at a behavioral explication. Because he has been so thorough and apt, my commentary can add little value to his thesis, only subtract from it. Therefore, rather than critique, I exemplify, and then simplify. By reducing his voluminous report to two lines: a theorem and an equation, I thereby encapsulate aesthetics in a sweet pill of spire. Aesthetic appreciation of this note may require a willing suspension of disbelief. [ABSTRACT FROM AUTHOR]

There is growing evidence for a coupling of actin assembly and myosin motor activity in cells. However, mechanisms for recruitment of actin nucleators and motors on specific membrane compartments remain unclear. Here we report how Spir actin nucleators and myosin V motors coordinate their specific membrane recruitment. The myosin V globular tail domain (MyoV-GTD) interacts directly with an evolutionarily conserved Spir sequence motif. We determined crystal structures of MyoVa-GTD bound either to the Spir-2 motif or to Rab11 and show that a Spir-2:MyoVa:Rab11 complex can form. The ternary complex architecture explains how Rab11 vesicles support coordinated F-actin nucleation and myosin force generation for vesicle transport and tethering. New insights are also provided into how myosin activation can be coupled with the generation of actin tracks. Since MyoV binds several Rab GTPases, synchronized nucleator and motor targeting could provide a common mechanism to control force generation and motility in different cellular processes.

Careful selection of dominant T cell epitope peptides of major allergens that display degeneracy for binding to a wide array of MHC class II molecules allows induction of clinical and immunological tolerance to allergen in a refined treatment strategy. From the original concept of peptide-induced T cell anergy arising from in vitro studies, proof-of-concept murine models and flourishing human trials followed. Current randomized, double-blind, placebo-controlled clinical trials of mixtures of T cell-reactive short allergen peptides or long contiguous overlapping peptides are encouraging with intradermal administration into non-inflamed skin a preferred delivery. Definitive immunological mechanisms are yet to be resolved but specific anergy, Th2 cell deletion, immune deviation, and Treg induction seem implicated. Significant efficacy, particularly with short treatment courses, in a range of aeroallergen therapies (cat, house dust mite, grass pollen) with inconsequential non-systemic adverse events likely heralds a new class of therapeutic for allergy, Synthetic Peptide Immuno-Regulatory Epitopes (SPIRE). [ABSTRACT FROM AUTHOR]