General directors who have all made their marks in the field of librarianship report from a variety of perspectives, including economic, social, educational, cultural developmental, and political. ...This information could increase the understanding of the managerial decisions, and other factors that affect the decisions and determine the library's overall policy and operations.
We present a new approach to search for a subsurface ocean within Ganymede through observations and modeling of the dynamics of its auroral ovals. The locations of the auroral ovals oscillate due to ...Jupiter's time‐varying magnetospheric field seen in the rest frame of Ganymede. If an electrically conductive ocean is present, the external time‐varying magnetic field is reduced due to induction within the ocean and the oscillation amplitude of the ovals decreases. Hubble Space Telescope (HST) observations show that the locations of the ovals oscillate on average by 2.0° ±1.3°. Our model calculations predict a significantly stronger oscillation by 5.8° ± 1.3° without ocean compared to 2.2°±1.3° if an ocean is present. Because the ocean and the no‐ocean hypotheses cannot be separated by simple visual inspection of individual HST images, we apply a statistical analysis including a Monte Carlo test to also address the uncertainty caused by the patchiness of observed emissions. The observations require a minimum electrical conductivity of 0.09 S/m for an ocean assumed to be located between 150 km and 250 km depth or alternatively a maximum depth of the top of the ocean at 330 km. Our analysis implies that Ganymede's dynamo possesses an outstandingly low quadrupole‐to‐dipole moment ratio. The new technique applied here is suited to probe the interior of other planetary bodies by monitoring their auroral response to time‐varying magnetic fields.
Key Points
New technique to search for a subsurface ocean in Ganymede with a telescope
Ocean affects auroral oscillation caused by time‐varying external magnetic field
HST observations reveal weak auroral oscillation and imply existence of ocean
CRISPR-Cas9-based genetic screens have successfully identified cell type-dependent liabilities in cancer, including acute myeloid leukemia (AML), a devastating hematologic malignancy with poor ...overall survival. Because most of these screens have been performed
using established cell lines, evaluating the physiologic relevance of these targets is critical. We have established a CRISPR screening approach using orthotopic xenograft models to validate and prioritize AML-enriched dependencies
, including in CRISPR-competent AML patient-derived xenograft (PDX) models tractable for genome editing. Our integrated pipeline has revealed several targets with translational value, including
as a metabolic vulnerability for AML addicted to exogenous myo-inositol and
as a critical guardian to prevent apoptosis in AML. MARCH5 repression enhanced the efficacy of BCL2 inhibitors such as venetoclax, further highlighting the clinical potential of targeting
in AML. Our study provides a valuable strategy for discovery and prioritization of new candidate AML therapeutic targets. SIGNIFICANCE: There is an unmet need to improve the clinical outcome of AML. We developed an integrated
screening approach to prioritize and validate AML dependencies with high translational potential. We identified
as a metabolic vulnerability and
as a critical apoptosis regulator in AML, both of which represent novel therapeutic opportunities.
.
On 7 June 2021, NASA's Juno mission obtained unique measurements of Ganymede's magnetosphere during a close flyby that brought the spacecraft within ∼1,000 km of its surface. Here Jupiter Energetic ...particle Detector Instrument observations are presented and analyzed. The electron pitch angle distributions reveal distinct regions of Ganymede's magnetosphere that can be characterized as inbound and outbound magnetospheric boundaries, a magnetotail/wake region, and Ganymede's open field line region. Evidence for energy dependent electron pitch angle structuring is also documented both outside and within Ganymede's magnetosphere. Electron precipitation is observed and mapped to Ganymede's surface along Juno's magnetic footpoint.
Plain Language Summary
Not only is Ganymede the largest moon in our solar system, it is also the only moon known to generate its own internal magnetic field and mini‐magnetosphere. This makes Ganymede extremely fascinating to study. On 7 June 2021, NASA's Juno mission performed a historic flyby with a closest approach altitude of ∼1,000 km above its surface. The data collected by Juno is providing us with new insights into this unique mini‐magnetosphere. This letter focuses on the energetic ion and electron environment that surrounds Ganymede and the features revealed by Juno's Jupiter Energetic particle Detector Instrument.
Key Points
Energetic particle measurements reveal new insights into Ganymede's magnetosphere for the only close Juno flyby
Electron pitch angle distributions reveal distinct regions of Ganymede's magnetosphere
Evidence for energetic electron precipitation onto Ganymede's surface within the open field line region
Characterizing Europa’s subsurface ocean is essential for assessing Europa’s habitability. The suite of instruments on the Europa Clipper spacecraft will, among others, magnetically sound Europa’s ...interior by measuring the ocean’s induced magnetic field. This magnetic field is generated in response to the Jovian time-varying magnetic environment in which Europa is immersed. However, the dynamic magnetized plasma flow of the Jovian magnetosphere creates electrical currents that give rise to magnetic perturbations near Europa. These perturbations complicate the interpretation of the induction signal, and hence the characterization and inferences on potential habitability. Thus, characterization of the ocean by magnetic sounding requires an accurate characterization of the plasma as it flows across Europa.
We present the Plasma Instrument for Magnetic Sounding (PIMS), the instrument for the Europa Clipper mission that will measure the plasma contribution to the magnetic field perturbations sensed by the Europa Clipper Magnetometer. PIMS is composed of four Faraday Cup plasma spectrometers that use voltage-biased gridded apertures to dissect the space plasmas that they encounter. The instrument uses sensitive preamplifiers and processing electronics to measure the current that results when charged particles strike the instrument’s metal collector plates, thus enabling a measure of the plasma characteristics near Europa to produce a more accurate magnetic sounding of Europa’s subsurface ocean. PIMS consists of two sensors: one placed near the top of the Europa Clipper spacecraft and one near the bottom. Each sensor contains two Faraday Cups with a 90° full-width field-of-view. The sensors were specifically designed to withstand the Europa environment, measure both ions and electrons, and have two separate voltage ranges intended to analyze the magnetospheric and ionospheric environments, respectively. In this paper, we describe the scientific motivation for this experiment, the design considerations for the PIMS instrument, the details of the ground calibration, and other details pertinent to understanding the scientific data retrieved by PIMS.
On 7 June 2021, Juno‐UVS mapped Ganymede's auroral emissions near a closest approach altitude of 1,046 km. The high spatial resolution map exhibits bright, 200–1,000 R, oxygen emissions organized ...into northern and southern auroral ovals. Though the map has incomplete global coverage, UVS observed longitudinal structure similar to that described by McGrath et al. (2013), https://doi.org/10.1002/jgra.50122 and latitudinal and vertical structure never before resolved. The mapped auroral emissions (a) display an intense narrow auroral curtain with a sharp poleward boundary, (b) have a more slowly decreasing equatorial edge on the leading hemisphere, (c) appear to originate near the surface with a vertical extent of 25–50 km, and (d) are slightly brighter in the north than the south. Additionally, we present UVS observations from the more distant Juno Ganymede flyby on 20 July 2021. We describe the observations, compare them to previous Hubble Space Telescope observations and current model predictions of the open‐closed‐field line‐boundary.
Plain Language Summary
Observations of Ganymede by Juno‐UVS during a close flyby (during Juno's 34th Jupiter orbit) captured unique high‐spatial‐resolution measurements of Ganymede's auroral emissions. Organized into two polar ovals, the positions and intensities of the auroral emissions are consistent with previous Hubble Space Telescope observations. The observed morphology of the auroras on the leading hemisphere of Ganymede exhibits latitudinal structure never before resolved. Previous studies suggest the poleward edge of the emissions trace the poleward most position of the magnetic field lines that have both ends rooted to Ganymede. We show that a magnetic field model of Ganymede within Jupiter's larger magnetosphere predicts last‐closed field‐lines very close to the observed auroral emissions, as expected. More distant observations taken during Juno's following orbit (orbit 35) capture auroral emissions at slightly different longitudes. They too show similar agreement with previous observations and current magnetic field models.
Key Points
The high spatial resolution observations revealed auroral emissions of over 1000 Rayleighs, brighter than previously observed
The leading hemisphere aurora exhibits an intense auroral curtain with a sharp poleward boundary and more slowly tapering equatorial edge
Juno‐UVS observed Ganymede's auroral emissions extending up to a maximum of 50 km altitude
edited byWolfgang G. Stock (Düsseldorf, Germany) in close cooperation with a board of co-editorsRonald E. Day (Bloomington, Indiana, U.S.A.),Richard J. Hartley (Manchester, U.K.),Robert M. Hayes (Los ...Angeles, California, U.S.A.),Peter Ingwersen (Copenhagen, Denmark),Michel J. Menou (Les Rosiers sur Loire, France, and London, U.K.),Stefano Mizzaro (Udine, Italy),Christian Schlögl (Graz, Austria),Sirje Virkus (Tallinn, Estonia) ISSN 1868-842X Knowledge and Information (K&I) is a peer-reviewed information science book series appearing as a print and as an ebook version, publishing high quality research monographs and topic-specific collections of papers as well. It covers information science to the full extent and alludes additionally to neighboring sciences such as computer science, computational linguistics, (information) business administration, and library science. The language of publication is English. The scope of information science comprehends representing, providing, searching and finding of relevant knowledge including all activities of information professionals (e.g., indexing and abstracting) and users (e.g., their information behavior). An important research area is information retrieval, the science of search engines and their users. Topics of knowledge representation include metadata as well as methods and tools of knowledge organization systems (folksonomies, nomenclatures, classification systems, thesauri, and ontologies). Informetrics is empirical information science and consists among others of the domain-specific metrics (e.g., scientometrics, webometrics, patent analysis), user and usage research, and evaluation of information systems. Knowledge management is concerned with the sharing and distribution of internal and external information in organizations. The information market can be defined by the exchange of digital information on networks, especial the World Wide Web. Further important research areas of information science are information ethics, information law, information sociology, and information policy. Information science provides basic research for other scientific fields, among others for computer science and for library science, and for a lot of practical endeavors, such as the construction of search engines, the organization of digital libraries as well as commercial information supply, the operation of catalogues of libraries, museums etc., the installation and maintenance of corporate knowledge management, the design of Web sites, and business strategies on the WWW. The editors like to invite all information science scholars to offer- monographs of research results (including Ph.D.-Theses) and- suggestions for collections of papersfor publication in K&I. All books may have a volume of about 300 pages or more. Monographs and articles in collections will be reviewed at least by two of the editors or co-editors. For proposals, suggestions, questions, etc. please contactWolfgang G. Stock ( stock@phil-fak.uni-duesseldorf.de ),Katsiaryna S. Baran ( Katsiaryna.Baran@uni-duesseldorf.de ) orone of the co-editors.
SNAIL is a key transcriptional regulator in embryonic development and cancer. Its effects in physiology and disease are believed to be linked to its role as a master regulator of ...epithelial-to-mesenchymal transition (EMT). Here, we report EMT-independent oncogenic SNAIL functions in cancer. Using genetic models, we systematically interrogated SNAIL effects in various oncogenic backgrounds and tissue types. SNAIL-related phenotypes displayed remarkable tissue- and genetic context-dependencies, ranging from protective effects as observed in KRAS- or WNT-driven intestinal cancers, to dramatic acceleration of tumorigenesis, as shown in KRAS-induced pancreatic cancer. Unexpectedly, SNAIL-driven oncogenesis was not associated with E-cadherin downregulation or induction of an overt EMT program. Instead, we show that SNAIL induces bypass of senescence and cell cycle progression through p16
-independent inactivation of the Retinoblastoma (RB)-restriction checkpoint. Collectively, our work identifies non-canonical EMT-independent functions of SNAIL and unravel its complex context-dependent role in cancer.
PDF
