The Settlement History of the Lucre Basin (Cusco, Peru)

This article reports the results of archaeological survey from Oropesa to Andahuayllilas, Peru

Rotavirus infection activates the UPR but modulates its activity

<p>Abstract</p> <p>Background</p> <p>Rotaviruses are known to modulate the innate antiviral defense response driven by IFN. The purpose of this study was to identify changes in the cellular proteome in response to rotavirus infection in the context of the IFN response. We also sought to identify proteins outside the IFN induction and signaling pathway that were modulated by rotavirus infection.</p> <p>Methods</p> <p>2D-DIGE and image analysis were used to identify cellular proteins that changed in levels of expression in response to rotavirus infection, IFN treatment, or IFN treatment prior to infection. Immunofluorescence microscopy was used to determine the subcellular localization of proteins associated with the unfolded protein response (UPR).</p> <p>Results</p> <p>The data show changes in the levels of multiple proteins associated with cellular stress in infected cells, including levels of ER chaperones GRP78 and GRP94. Further investigations showed that GRP78, GRP94 and other proteins with roles in the ER-initiated UPR including PERK, CHOP and GADD34, were localized to viroplasms in infected cells.</p> <p>Conclusions</p> <p>Together the results suggest rotavirus infection activates the UPR, but modulates its effects by sequestering sensor, transcription factor, and effector proteins in viroplasms. The data consequently also suggest that viroplasms may directly or indirectly play a fundamental role in regulating signaling pathways associated with cellular defense responses.</p

The Rogue Alpha and Beta Mission: Operations, Infrared Remote Sensing, LEO Data Processing, and Lessons Learned From Three Years on Orbit With Two Laser Communication-Equipped 3U CubeSats

The Aerospace Corporation\u27s Rogue-alpha, beta program was a rapid prototyping demonstration aimed at building and deploying an infrared remote sensing capability into low Earth orbit within 18 months. The two satellites and their data were then used for three years as an experimental testbed for future proliferated low Earth orbit (pLEO) constellations. Their launch took place on November 2, 2019, followed by boost and deployment of two identical spacecraft (Rogue-alpha and beta) by the Cygnus ISS cargo vessel into circular 460-km, 52° inclined orbits on January31, 2020. The primary sensors were 1.4-micron band, InGaAs short wavelength infrared (SWIR) cameras with640x512 pixels and a 28° field-of-view. The IR sensors were accompanied by 10-megapixel visible context cameras with a 37° field-of-view. Star sensors were also tested as nighttime imaging sensors. Three years of spacecraft and sensor operations were achieved, allowing a variety of experiments to be conducted. The first year focused on alignment and checkout of the laser communication systems, sensor calibration, and priority IR remote sensing objectives, including the study of Earth backgrounds, observation of natural gas flares, and detection of rocket launches. The second year of operations added study of environmental remote sensing targets, including severe storms, wildfires, and volcanic eruptions, while continuing to gather Earth backgrounds and rocket launch observations. The final year emphasized advanced data processing and exploitation techniques applied to collected data, using machine learning and artificial intelligence for tasks such as target tracking, frame co-registration, and stereo data exploitation. Mission operations continued in the final year, with an emphasis on collecting additional rocket launch data, and higher frame rate backgrounds data. This report summarizes the Rogue alpha, beta mission’s outcomes and presents processed IR data, including the detection and tracking of rocket launches with dynamic Earth backgrounds, embedded moving targets in background scenes, and the use of pointing-based registration to create fire line videos of severe wildfires and 3D scenes of pyrocumulonimbus clouds. Lessons learned from the experimental ConOps, data exploitation, and database curation are also summarized for application to future pLEO constellation missions

The development and validation of a golf swing and putt skill assessment for children

The aim was to describe development of a process-oriented instrument designed to assess the golf swing and putt stroke, and to assess the instrument’s discriminative validity in terms of age and reliability (intra-rater and re-test). A Delphi consultation (with golf industry professionals and researchers in movement skill assessment) was used to develop an assessment for each skill based on existing skill assessment protocols. Each skill had six components to be marked as present/absent. Individual scores were based on the number of performance components successfully demonstrated over two trials for each skill (poten-tial score range 0 to 24). Children (n = 43) aged 6-10 years (M = 7.8 years, SD = 1.3) were assessed in both skills live in the field by one rater at Time 1(T1). A subset of children (n = 28) had consent for assessments to be videoed. Six weeks later 19 chil-dren were reassessed, five days apart (T2, T3). An ANOVA assessed discriminative validity i.e. whether skill competence at T1 differed by age (6 years, 7/8 years and 9/10 years). Intraclass correlations (ICC) assessed intra-rater reliability between the live and video assessment at T1 and test-retest reliability (be-tween T2 and T3). Paired t-tests assessed any systematic differ-ences between live and video assessments (T1) and between T2 and T3. Older children were more skilled (F (2, 40) = 11.18, p < 0.001). The live assessment reflected the video assessment (ICC = 0.79, 95% CI 0.59, 0.90) and scores did not differ between live and video assessments. Test retest reliability was acceptable (ICC = 0.60, 95% CI 0.23, 0.82), although the mean score was slightly higher at retest. This instrument could be used reliably by golf coaches and physical education teachers as part of sys-tematic early player assessment and feedback

Landsat Imagery from a CubeSat: Results and Operational Lessons from the R3 Satellite\u27s First 18 Months in Space

R3 is a 3-U CubeSat launched on a RocketLab Electron into a 500 km circular orbit at 85° inclination on December 16th, 2018. The spacecraft flies a multispectral sensor that takes data in the six Landsat visible and near infrared bands. The R3 sensor mates a custom refractive telescope with a Materion Precision Optics Landsat filter, and an ON Semiconductor fast-framing high-sensitivity Si CMOS array, to produce 50-km wide, 44-m resolution Landsat-like image strips. Data are taken in push-broom mode and are downlinked via a 100Mbps compact lasercom system. Frames are then co-added on the ground in time-delay-integration (TDI) fashion to increase signal-to-noise ratio and create multi-spectral Earth images from the compact sensor. The system is an engineering concept demonstration of a compact multispectral sensor in CubeSat form. We describe our ConOps, flight operations, sensor focus and alignment, initial imaging check out, and initial comparisons of R3 data to Landsat-8 imagery of the same Earth locations. RGB, color infrared, and normalized differential vegetation index (NDVI) products are compared between CUMULOS and Landsat-8. Results show good multispectral image quality from the CubeSat sensor, and illustrate the ability of R3 to detect vegetation and other features in a manner similar to Landsat, as well as the challenge in perfectly exposing all 6 VIS/NIR Landsat bands using our commercial 10-bit CMOS array. We also highlight the performance of the compact laser communications system which enabled the successful performance of this mission

Remote Sensing Experiments Using the Rogue-alpha,beta CubeSats as a Constellation: High Frame Rate Environmental Observations from Agile, Taskable, Infrared and Visible Sensors in Low Earth Orbit

The Aerospace Corporation’s Rogue-alpha,beta program built and launched two 3-Unit CubeSats in 18-months, each equipped with modified commercial infrared camera payloads, visible context cameras, laser communications and precision pointing capabilities. Launched on November 2, 2019, the two spacecraft (Rogue-alpha and beta) were boosted and released from the International Space Station Cygnus NG-12 robotic resupply spacecraft on January 31, 2020 into a circular 460-km, 52° inclined orbit. The primary Rogue IR sensor is a 1.4-micron band, 640x512 pixel, 28° field of view, InGaAs short wavelength infrared (SWIR) camera. It is accompanied by a panchromatic, 10-megapixel, 37° field of view visible context camera. In addition, the narrow- and wide-field-of-view star sensors may also be utilized as nighttime sensors. During the first two years of spaceflight, the Rogue satellites conducted a series of experiments using both spacecraft to conduct cooperative remote sensing observations and to test the capabilities of the 1.4-micron water overtone band. These included: 1) fore-aft pointing using two spacecraft for stereo observations of cloud structure and altitude, 2) horizon-pointed imaging in all directions relative to the spacecraft orbit (fore, aft, port, and starboard) to maximize the imaged field of view, 3) pre-programmed point-and-stare imaging, 4) nadir-pointed operations for vicarious calibration with other satellites. All of these modes of operation are usually conducted in multi-frame collections at 1-20 frames-per-second for dozens to thousands of frames. During the mission we investigated different modes of collecting data, taking advantage of the evolving orbital spacing of the pair of CubeSats. Initial close satellite spacing allowed along-track fore-aft stereo observations of weather formations, as well as pre-programmed tip-and-queue observations, and sequential point-and-stare experiments aimed at collecting minutes of data on targets of interest. Cloud altitude was measured on weather events by simultaneous stereo observations, and by mono observations using the changing view angles during a constant point along track or slewing during a pass. Observations were collected on hurricanes, typhoons, thunderstorms, monsoon storms, and forecasted tornadic weather. Unique observations of severe wildfires were collected, exploring the capability for our 1.4micron band to detect fires during daytime, and to characterize pyrocumulonimbus clouds. Nighttime observations were also made of human lighting, infrared sources, and moonlight-illuminated clouds, including observations utilizing the Rogue satellites’ star sensors for remote sensing tests. These experiments collectively explored the possibilities for dynamically tasked, high-frame-rate, low-earth-orbit sensors to carry out weather and environmental monitoring missions in ways that differ from traditional scanned or push-broom satellite sensor systems. We will present a summary of our tasking ConOps, observations of weather events and fires, and highlight results and techniques for cloud height characterization by our two CubeSat constellation during its first two years on orbit. Our results with two satellites demonstrate possibilities for future missions using cooperative tasking in larger constellations of dynamically tasked sensors in low Earth orbit

Identification of novel subgroup a variants with enhanced receptor binding and replicative capacity in primary isolates of anaemogenic strains of feline leukaemia virus

&lt;b&gt;BACKGROUND:&lt;/b&gt; The development of anaemia in feline leukaemia virus (FeLV)-infected cats is associated with the emergence of a novel viral subgroup, FeLV-C. FeLV-C arises from the subgroup that is transmitted, FeLV-A, through alterations in the amino acid sequence of the receptor binding domain (RBD) of the envelope glycoprotein that result in a shift in the receptor usage and the cell tropism of the virus. The factors that influence the transition from subgroup A to subgroup C remain unclear, one possibility is that a selective pressure in the host drives the acquisition of mutations in the RBD, creating A/C intermediates with enhanced abilities to interact with the FeLV-C receptor, FLVCR. In order to understand further the emergence of FeLV-C in the infected cat, we examined primary isolates of FeLV-C for evidence of FeLV-A variants that bore mutations consistent with a gradual evolution from FeLV-A to FeLV-C.&lt;p&gt;&lt;/p&gt; &lt;b&gt;RESULTS:&lt;/b&gt; Within each isolate of FeLV-C, we identified variants that were ostensibly subgroup A by nucleic acid sequence comparisons, but which bore mutations in the RBD. One such mutation, N91D, was present in multiple isolates and when engineered into a molecular clone of the prototypic FeLV-A (Glasgow-1), enhanced replication was noted in feline cells. Expression of the N91D Env on murine leukaemia virus (MLV) pseudotypes enhanced viral entry mediated by the FeLV-A receptor THTR1 while soluble FeLV-A Env bearing the N91D mutation bound more efficiently to mouse or guinea pig cells bearing the FeLV-A and -C receptors. Long-term in vitro culture of variants bearing the N91D substitution in the presence of anti-FeLV gp70 antibodies did not result in the emergence of FeLV-C variants, suggesting that additional selective pressures in the infected cat may drive the subsequent evolution from subgroup A to subgroup C.&lt;p&gt;&lt;/p&gt; &lt;b&gt;CONCLUSIONS:&lt;/b&gt; Our data support a model in which variants of FeLV-A, bearing subtle differences in the RBD of Env, may be predisposed towards enhanced replication in vivo and subsequent conversion to FeLV-C. The selection pressures in vivo that drive the emergence of FeLV-C in a proportion of infected cats remain to be established

Imaging the real space structure of the spin fluctuations in an iron-based superconductor

Spin fluctuations are a leading candidate for the pairing mechanism in high temperature superconductors, supported by the common appearance of a distinct resonance in the spin susceptibility across the cuprates, iron-based superconductors and many heavy fermion materials1. The information we have about the spin resonance comes almost exclusively from neutron scattering. Here we demonstrate that by using low-temperature scanning tunneling microscopy and spectroscopy we can characterize the spin resonance in real space. We establish that inelastic tunneling leads to the characteristic "dip-hump" feature seen in tunneling spectra in high temperature superconductors and that this feature arises from excitations of the spin fluctuations. Spatial mapping of this feature near defects allows us to probe non-local properties of the spin susceptibility and to image its real space structure.Publisher PDFPeer reviewe

A Study on the Effects of Ball Defects on the Fatigue Life in Hybrid Bearings

Hybrid ball bearings using silicon nitride ceramic balls with steel rings are increasingly being used in space mechanism applications due to their high wear resistance and long rolling contact fatigue life. However, qualitative and quantitative reports of the effects of ball defects that cause early fatigue failure are rare. We report on our approach to study these effects. Our strategy includes characterization of defects encountered in use, generation of similar defects in a laboratory setting, execution of full-scale bearing tests to obtain lifetimes, post-test characterization, and related finite-element modeling to understand the stress concentration of these defects. We have confirmed that at least one type of defect of appropriate size can significantly reduce fatigue life. Our method can be used to evaluate other defects as they occur or are encountered