Characteristics of Impact Craters and Interior Deposits: Analysis of the Spatial and Temporal Distribution of Volatiles in the Highlands of Mars

The martian southern highlands contain impact craters that display pristine to degraded morphologies, and preserve a record of degradation that can be attributed to fluvial, eolian, mass wasting, volcanic and impact-related processes. However, the relative degree of modification by these processes and the amounts of material contributed to crater interiors are not well constrained. Impact craters (D>10 km) within Terra Cimmeria (0deg-60degS, 190deg-240degW), Terra Tyrrhena (0deg-30degS, 260deg-310degW) and Noachis Terra (20deg-50degS, 310deg-340degW) are being examined to better understand the degradational history and evolution of highland terrains. The following scientific objectives will be accomplished. 1) Determine the geologic processes that modified impact craters (and surrounding highland terrains). 2) Determine the sources (e.g. fluvial, lacustrine, eolian, mass wasting, volcanic, impact melt) and relative amounts of material composing crater interior deposits. 3) Document the relationships between impact crater degradation and highland fluvial systems. 4) Determine the spatial and temporal relationships between degradational processes on local and regional scales. And 5) develop models of impact crater (and highland) degradation that can be applied to these and other areas of the martian highlands. The results of this study will be used to constrain the geologic, hydrologic and climatic evolution of Mars and identify environments in which subsurface water might be present or evidence for biologic activity might be preserved

Geologic Mapping of MTM -30247, -35247 and -40247 Quadrangles, Reull Vallis Region of Mars

Geologic mapping and stratigraphic analyses of MTM -30247, -35247, and -40247 quadrangles are being used to characterize the Reull Vallis (RV) system and to determine the history of the eastern Hellas region of Mars. Studies of RV examine the roles and timing of volatile-driven erosional and depositional processes and provide constraints on potential associated climatic changes. This study complements earlier investigations of the eastern Hellas region, including regional analyses [1-6], mapping studies of circum-Hellas canyons [7-10], and volcanic studies of Hadriaca and Tyrrhena Paterae [11-13]. Key scientific objectives for these quadrangles include 1) characterization of RV in its "fluvial zone," 2) analysis of channels in the surrounding plains and potential connections to and interactions with RV, 3) examination of young (?), presumably sedimentary plains along RV that embay the surrounding highlands, and 4) determination of the nature of the connection between segments 1 and 2 of RV

Geology of -30247, -35247, and -40247 Quadrangles, Southern Hesperia Planum, Mars

Geologic mapping of MTM -30247, -35247, and -40247 quadrangles is being used to characterize Reull Vallis (RV) and examine the roles and timing of volatile-driven erosional and depositional processes. This study complements earlier investigations of the eastern Hellas region, including regional analyses [1-6], mapping studies of circum-Hellas canyons [7-10], and volcanic studies of Hadriaca and Tyrrhena Paterae [11-13]. Key scientific objectives include 1) characterizing RV in its "fluvial zone," and evaluating its history of formation, 2) analyzing channels in the surrounding plains and potential connections to RV, and 3) examining young, possibly sedimentary plains along RV

Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30)

In this study we use recent image, spectral and topographic data to map the geology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-7]. The overall objective of this research is to constrain the geologic evolution of LQ-30 (60 -90 S, 0 - 180 ) with specific emphasis on evaluation of a) the regional effects of impact basin formation, and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Determining the geologic history of LQ-30 and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of potential resources (e.g., H, Fe, Th) and their relationships with surface materials

Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schroedinger Basin

In this study we use recent images and topographic data to map the geology and geomorphology of the lunar South Pole quadrangle (LQ-30) at 1:2.5M scale [1-4] in accordance with the Lunar Geologic Mapping Program. Mapping of LQ-30 began during Mest's postdoctoral appointment and has continued under the PG&G Program, from which funding became available in February 2009. Preliminary map-ping and analyses have been done using base materials compiled by Mest, but properly mosaicked and spatially registered base materials are being compiled by the USGS and should be received by the end of June 2009. The overall objective of this research is to constrain the geologic evolution of the lunar South Pole (LQ-30: 60deg -90deg S, 0deg - +/-180deg ) with specific emphasis on evaluation of a) the regional effects of basin formation on the structure and composition of the crust and b) the spatial distribution of ejecta, in particular resulting from formation of the South Pole-Aitken (SPA) basin and other large basins. Key scientific objectives include: 1) Constraining the geologic history of the lunar South Pole and examining the spatial and temporal variability of geologic processes within the map area. 2) Constraining the vertical and lateral structure of the lunar regolith and crust, assessing the distribution of impact-generated materials, and determining the timing and effects of major basin-forming impacts on crustal structure and stratigraphy in the map area. And 3) assessing the distribution of resources (e.g., H, Fe, Th) and their relationships with surface materials

Characterization of Lunar Farside Plains

The Moon contains broad and isolated areas of plains that have been recognized as mare, cryptomare, impact ejecta, or impact melt. These deposits have been extensively studied on the lunar nearside by remote sensing via telescopes and numerous spacecraft, and in some cases, in situ robotically and by astronauts. Only recently have the deposits on the entire farside been able to be observed and evaluated to the same degree. There are spatially extensive plains deposits located throughout the lunar farside highlands whose formation has remained ambiguous. Many of the plains deposits in the lunar farside highlands display higher albedos than mare materials. Some deposits are located in close proximity to relatively younger impact craters suggesting that plains could be composed of cryptomare or ejecta materials. Some deposits are within the range in which ejecta from large basin-forming events (e.g., SPA and Orientale) likely distributed large amounts of ejecta across the surface. Here we are conducting a series of observations and models in order to resolve the nature and origin of lunar farside plains deposits. Understanding these plains is important for understanding the volcanic and impact histories of the lunar farside, and is important for future mapping and thermal modeling studies

ArcGIS Digitization of Apollo Surface Traverses

The Apollo surface activities were documented in extraordinary detail, with every action performed by the astronauts while on the surface recorded either in photo, audio, film, or by written testimony [1]. The samples and in situ measurements the astronauts collected while on the lunar surface have shaped our understanding of the geologic history of the Moon, and the earliest history and evolution of the inner Solar System. As part of an ongoing LASERfunded effort, we are digitizing and georeferencing data from astronaut traverses and spatially associating them to available, co-registered remote sensing data. Here we introduce the products produced so far for Apollo 15, 16, and 17 missions

Spectrophotometric Properties of Geologically Young Regions on Ceres

Introduction: Results from the Dawn mission showed us an aqueously altered cryovolcanic world of Ceres, maybe a relict Ocean World [1, 2]. Geological studies suggested brine-driven features, including the cryovolcanic dome Ahuna Mons [3] and the Cerealia and Vinalia Faculae, which are carbonate- and chloride-rich evaporites [4] formed from brine extrusion with evidence of recent activity [5]. In addition, the Haulani crater is among the youngest impact features on Ceres [6], potentially excavating relatively fresh, volatile-rich subsurface materials with distinctly bright and blue spectral characteristics [7]. In this study, we focus on the spectrophotometric properties of the geologically young features, aiming to characterize Ceres's regolith evolution and better understand the cryovolcanic processes. Here we report the preliminary results of the Haulani crater (latitude -3º to 14º, longitude 0º to 20º) and Ahuna Mons regions (latitude -17º to -3º, longitude 308º - 322º). Data: We used the multiband images of Ceres collected by the Dawn Framing Camera with pixel scales , with rmeasure and rmodel being the measured and modeled reflectance, respectively, N being the number of data points, and being the average measured reflectance, is 4-9%, compared to 4-6% of the global model [11], suggesting a reasonably good fit. The similar results for the background ROIs in all bands in the two regions indicate consistent model fitting across all ROIs. However, the 0º roughness parameter retrieved for the Ahuna Mons ROI in some bands is probably problematic, as also indicated by the relatively high model RMS for this ROI. Figure 2. Modeled Hapke parameters for all ROIs in the Haulani crater region (a) and the Ahuna Mons region (b). A comparison of all ROIs suggests that: 1) The photometric properties in the Haulani crater region are more diverse than those in the Ahuna Mons region. 2) The albedo spectra of all ROIs show a spectral feature centered in the 750 nm filter with varying characteristics. The nature of this feature is unclear. We further calculated the spectral slopes of the SSA and the g-parameter (excluding 440 nm) to quantify the color and phase reddening of all ROIs. Conclusion and Discussion: Our results suggest that these ROIs likely form a trend, with the Haulani crater floor and Ahuna Mons as exceptions (Fig. 3). The apparent trendline of roughness vs. SSA is opposite of what was usually observed in asteroids caused by multiple scattering into shadows. What this trend means to Ceres's regolith is still under investigation. On the other hand, the Haulani crater floor material is clearly below the trendline. Ahuna Mons is below the trendline, but the fitted 0º roughness is dubious. Fig. 3b shows that the trendline is primarily formed by the ROIs in the Haulani crater region. The points of the Ahuna Mons region ROIs cluster near the background. The Haulani crater floor and Ahuna Mons are clearly out of the trendline. Given the much younger geological age of the Haulani crater region of ~2 Ma [6] than that of the Ahuna Mons region (~200 Ma for Ahuna Mons [3], ~600 Ma for Yalode ejecta [13]), if the trendline represents an evolutionary sequence, then the corresponding timescale is around several Ma. Figure 3. Roughness parameter vs. SSA for all ROIs at all bands (a) and the spectral slope of the g-parameter vs. that of the SSA (b). The dashed lines represent eye-balled trendlines. We note that our results presented here are preliminary. The statistical significance of the trendline needs to be further accessed from the model uncertainties. But overall, such an evolutionary trend is in line with the previous results about the regolith evolution caused by the devolatilization of ice-rich materials near young craters [14, 15]. Acknowledgments: This research is supported by NASA Grant #80NSSC21K1017 and partially by the SSERVI16 Cooperative Agreement (#NNH16ZDA001N), SSERVI-TREX. References: [1] Hendrix, A.R., et al., 2019, Astrobiology 19, 1; [2] De Sanctis, M.C., et al. 2020a, SSR 216, 60; [3] Ruesch, O., et al., 2016, Science 353, 1005; [4] Raponi, A., et al., 2019. Icarus 320, 83; [5] De Sanctis, M.C., et al. 2020b, Nature Astron. 4, 786; [6] Krohn, K., et al., 2018, Icarus 316, 84; [7] Schröder, S.E., et al., 2017, Icarus 288, 201; [8] Schröder, S.E., et al., 2013, Icarus 226, 1304; [9] Schröder, S.E., et al., 2014, Icarus 234, 99; [10] Roatsch et al. 2017, DAWN-A-FC2-5- CERESLAMODTMSPG-V1.0, NASA Planetary Data System; [11] Li, J.-Y., et al., 2019, Icarus 322, 144; [12] Helfenstein, P., Veverka, J., 1989, In: Asteroids II, 557; [13] Crown, D.A. et al. 2018, Icarus 316, 167; [14] Stephan, K., et al., 2017, GRL 44, 1660; [15] Schröder, S.E., et al., 2021, Nature Comm. 12, 274

Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review

The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59–0.90% and 0.77–1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups

Coordinate control of cell cycle regulatory genes in zebrafish development tested by cyclin D1 knockdown with morpholino phosphorodiamidates and hydroxyprolyl-phosphono peptide nucleic acids

During early zebrafish (Danio rerio) development zygotic transcription does not begin until the mid-blastula transition (MBT) ∼3 h after fertilization. MBT demarcates transition from synchronous short cell cycles of S and M phases exclusively to full cycles encompassing G(1) and G(2) phases. Transcriptional profiling and RT–PCR analyses during these phases enabled us to determine that this shift corresponds to decreased transcript levels of S/M phase cell cycle control genes (e.g. ccna2, ccnb1, ccnb2 and ccne) and increased transcript levels of ccnd1, encoding cyclin D1, and orthologs of p21 (p21-like) and retinoblastoma (Rb-like 1). To investigate the regulation of this process further, the translation of ccnd1 mRNA, a G(1)/S checkpoint control element, was impaired by microinjection of ccnd1-specific morpholino phosphorodiamidate (MO) 20mer or hydroxyprolyl-phosphono peptide nucleic acid (HypNA-pPNA) 16mer antisense oligonucleotides. The resulting downregulation of cyclin D1 protein resulted in microophthalmia and microcephaly, but not lethality. The phenotypes were not seen with 3-mismatch MO 20mers or 1-mismatch HypNA-pPNA 16mers, and were rescued by an exogenous ccnd1 mRNA construct with five mismatches. Collectively, these results indicate that transcription of key molecular determinants of asynchronous cell cycle control in zebrafish embryos commences at MBT and that the reduction of cyclin D1 expression compromises zebrafish eye and head development