15 research outputs found
Extended Silicic Volcanism in the Gruithuisen Region—Revisiting the Composition and Thermophysical Properties of Gruithuisen Domes on the Moon
The formation mechanisms, extent, and compositions of red spots on the lunar surface have intrigued the lunar community for decades. By identifying a new dome and another silicic crater in the highlands nearby, we find that the silicic volcanism in the Gruithuisen region extends beyond the three major domes. Our observations indicate that the Gruithuisen domes have low iron and titanium contents. They are enveloped by ejecta from surrounding regions and host silica-rich material excavated by the young craters consistent with previous work. Our boulder maps of the Gamma dome display a high boulder count and indicate that the Diviner rock abundance maps are only sensitive to boulders larger than ∼2 m. The H-parameter values are sensitive to presence of rocks and may be a better indicator of rocks at submeter scales. The Delta dome has gentle slopes, lower rock abundance, and one young crater, and it could serve as a safe and scientifically valuable site for landing and exploration of the domes and nearby region. The dome also displays anomalously high H-parameter in the same region as the crater, indicating the potential presence of pyroclastic materials. We observe up to 200 ppm of OH/H2O on the domes and nearby mare despite the presence of a weak magnetic field to the south of Delta dome, further supporting the potential presence of pyroclastics in the region. This study could potentially aid in logistical and scientific decisions of the future NASA missions in the region
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Temperatures of the Lacus Mortis Region of the Moon
Over 11 years of data acquired by the Diviner Lunar Radiometer Experiment instrument aboard Lunar Reconnaissance Orbiter have been compiled into a comprehensive data set of surface temperatures in the Lacus Mortis region which includes the landing ellipse of the Astrobotic Mission One lander mission. These data provide diurnal brightness temperatures at 128 pixels per degree (ppd) spatial resolution and 0.1 hr of local time resolution. From this data set, we highlight several features that display variations in radiative and thermophysical properties in the Lacus Mortis region and characterize the temperatures of the Astrobotic Mission One landing ellipse. We identify distinctly contrasting properties of materials in the walls of Bürg crater, hummocks of materials on the southeast margin of the mare basalts, and materials exposed or excavated by impacts. Additionally, we describe an exceptionally rocky fault scarp that predates the formation of Bürg crater suggesting the observed boulders are replenished on a timescale <1 Ga. Within the Astrobotic landing ellipse, temperatures are observed to range from ∼88 to ∼359 K with sunrise and sunset local times constrained to 5.8–6.3 hr and 17.8 and 18.1 hr respectively.
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Primary plasmablastic lymphoma of the central nervous system in an immunocompetent man: A case report and review of literature
Plasmablastic lymphoma (PBL) is an aggressive non-Hodgkin lymphoma classically occurring in individuals infected with human immunodeficiency virus (HIV). It has a predilection for the oral cavity and jaw. However, recent case reports have shown this variety of lymphoma in the stomach, lung, nasal cavity, cervical lymph nodes and jejunum in HIV-negative individuals. In this manuscript we report a case of primary PBL of brain in an HIV-negative heterosexual man, who presented with multiple episodes of seizures and hemiparesis. It proved a diagnostic challenge as initial stereotactic brain biopsy showed only few necrotic fragments and possibility of glioblastoma multiforme was rendered. Later patient underwent craniotomy and subsequent histopathology combined with immunohistochemistry led us in making a correct diagnosis of extramedullary PBL. Extensive systemic work up failed to reveal any disease outside the central nervous system. Only single case of primary PBL of brain in HIV-negative individual has been reported until date. To the best of our knowledge, this is the second report to suggest such an association
Dynamic Secondary Illumination in Permanent Shadows within Artemis III Candidate Landing Regions
Investigations that can be conducted at the Artemis III candidate landing regions will benefit from the knowledge of the thermal environment within permanently shadowed regions (PSRs). Within PSRs, secondary illumination controls the surface temperature, varying diurnally and seasonally, affecting the stability and concentration of volatiles cold-trapped within the PSRs. In this case study, we characterize the dynamic nature of secondary illumination at four PSRs that overlap five of the Artemis III candidate landing regions. Our analysis is based on secondary illumination model-generated images paired with PSR images acquired by ShadowCam on board the Korean Pathfinder Lunar Orbiter. We find that illumination and thermal conditions can change rapidly within the PSRs, and knowledge of time-variable secondary illumination can be decisive for the efficient design of investigations and sample collection operations at the PSRs
ERCC1 expression in patients with colorectal cancer: a pilot study
Aim: Excision repair cross complementation group 1 (ERCC1) has a key role in enhanced DNA damage repair caused by oxaliplatin-based therapy and may lead to resistance of these platinum drugs in colorectal cancer (CRC) patients. Hence, the present preliminary study aimed to explore the role of ERCC1 C/T polymorphism at codon 118 as well as its immunoreactivity in patients with primary CRC. Methods: ERCC1 polymorphism was studied using PCR-RFLP and ERCC1 protein expression was examined by immunohistochemistry in 50 CRC patients. Results: ERCC1 codon 118 C/T polymorphism analysis reported the predominance of C/T (52%) genotype as compared to C/C (38%) and T/T (10%) genotypes. Furthermore, 72% of patients showed positive ERCC1 protein expression. Significant correlation was not observed between clinicopathological parameters and ERCC1 polymorphism, while ERCC1 protein expression significantly correlated only with tumor site (colon vs. rectum) (P = 0.046). Further, the present study failed to demonstrate the role of ERCC1 C118T polymorphism or protein expression as useful prognostic markers in CRC patients. Conclusion: ERCC1-positive protein expression may be a useful marker for rectal cancer patients. However, further evaluation in a larger set of CRC patients is required to better understand the role of ERCC1
Geological characterization of Chandrayaan-2 landing site in the southern high latitudes of the Moon
ISRO's lunar orbiter-lander-rover mission Chandryaan-2 is scheduled to be launched in the mid of 2019. In this contribution, we have carried out detailed geological characterization of the prime landing site (70.9°S, 22.8°E) of the Chandrayaan-2 lander – “Vikram”. The proposed landing site is located amidst the nearside lunar highlands at high southern latitudes, which is ~350 km north of South Pole Aitken (SPA) basin rim. Topography of the region is generally flat and it is largely confined by craters of varying diameter. The majority (94%) of the landing ellipse (~15 × 8 km) is within the boundary of intercrater plains with a slope <15° and yields a crater retention age of ~3.7−0.04+0.03 Ga. Craters (diameter: ~2.28 m to ~1.13 km) consistent with morphologies varying from fresh to degraded are common within the landing ellipse, though the ellipse center is devoid of craters with significant depth. Analysis of the spectral reflectance data suggests that the landing ellipse is dominantly feldspathic/highland material. The estimated average abundance of elements within the landing ellipse are Fe: 4.2 wt%, Mg: 5.4 wt%, Ca: 10 wt%, and Ti: 0.3 wt%. Results indicate that the surface composition might correspond to FAN dominated material. Based on elemental and spectral analysis results, we envisage possible mixing of highland material with ejecta from multiple craters surrounding the landing ellipse and/or SPA basin, resulting in hybridisation of highland regolith. Together, the results provide a contextual framework for in situ investigations at the proposed landing site