419 research outputs found
Submicron full- color LED pixels for microdisplays and micro- LED main displays
We demonstrate a bottom- up approach to the construction of micro- LEDs as small as 150 nm in lateral dimension. Molecular beam epitaxy (MBE) is used to fabricate such nanostructured LEDs from InGaN, from the blue to red regions of the spectrum, providing a single material set useful for an entire RGB display.We demonstrate a bottom- up approach to the construction of micro- LEDs as small as 150 nm in lateral dimension. Molecular beam epitaxy (MBE) is used to fabricate such nanostructured LEDs from InGaN, from the blue to red regions of the spectrum, providing a single material set useful for an entire RGB display. We then consider collective effects of arrays of such LEDs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155468/1/jsid899_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155468/2/jsid899.pd
Post-mortem assessment in vascular dementia: advances and aspirations.
BACKGROUND: Cerebrovascular lesions are a frequent finding in the elderly population. However, the impact of these lesions on cognitive performance, the prevalence of vascular dementia, and the pathophysiology behind characteristic in vivo imaging findings are subject to controversy. Moreover, there are no standardised criteria for the neuropathological assessment of cerebrovascular disease or its related lesions in human post-mortem brains, and conventional histological techniques may indeed be insufficient to fully reflect the consequences of cerebrovascular disease. DISCUSSION: Here, we review and discuss both the neuropathological and in vivo imaging characteristics of cerebrovascular disease, prevalence rates of vascular dementia, and clinico-pathological correlations. We also discuss the frequent comorbidity of cerebrovascular pathology and Alzheimer's disease pathology, as well as the difficult and controversial issue of clinically differentiating between Alzheimer's disease, vascular dementia and mixed Alzheimer's disease/vascular dementia. Finally, we consider additional novel approaches to complement and enhance current post-mortem assessment of cerebral human tissue. CONCLUSION: Elucidation of the pathophysiology of cerebrovascular disease, clarification of characteristic findings of in vivo imaging and knowledge about the impact of combined pathologies are needed to improve the diagnostic accuracy of clinical diagnoses
ROSIsat
As the cost of sending satellites into space continues to drive down, the use of CubeSats for orbital missions continues to rise. Even though these satellites are smaller than traditional satellites, they still provide the ability to take on important science-based missions at a fraction of the cost. The Radiation Orbital Shielding Investigation satellite (ROSIsat) otherwise known as Project Hermes, will be the first student-built satellite for Embry-Riddle’s Daytona Beach campus. The main research mission of Project Hermes consists of shielding onboard flight computer memory modules from space radiation using various materials and substances. These materials include simulated Martian and Lunar regolith. To send a student-built CubeSat to space, the Hermes team is designing and integrating the majority of the satellite’s components in-house. These in-house components include the CubeSat’s electronics system, avionics, payload bay, and magnetorquer. Project Hermes will provide students with educational, technical, scientific, and legal knowledge that can be applied in their respective futures
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p27 allosterically activates cyclin-dependent kinase 4 and antagonizes palbociclib inhibition.
The p27 protein is a canonical negative regulator of cell proliferation and acts primarily by inhibiting cyclin-dependent kinases (CDKs). Under some circumstances, p27 is associated with active CDK4, but no mechanism for activation has been described. We found that p27, when phosphorylated by tyrosine kinases, allosterically activated CDK4 in complex with cyclin D1 (CDK4-CycD1). Structural and biochemical data revealed that binding of phosphorylated p27 (phosp27) to CDK4 altered the kinase adenosine triphosphate site to promote phosphorylation of the retinoblastoma tumor suppressor protein (Rb) and other substrates. Surprisingly, purified and endogenous phosp27-CDK4-CycD1 complexes were insensitive to the CDK4-targeting drug palbociclib. Palbociclib instead primarily targeted monomeric CDK4 and CDK6 (CDK4/6) in breast tumor cells. Our data characterize phosp27-CDK4-CycD1 as an active Rb kinase that is refractory to clinically relevant CDK4/6 inhibitors
Beyond Innovation and Competition: The Need for Qualified Transparency in Internet Intermediaries
The Planteome database:an integrated resource for reference ontologies, plant genomics and phenomics
The Planteome project (http://www.planteome.org) provides a suite of reference and species-specific ontologies for plants and annotations to genes and phenotypes. Ontologies serve as common standards for semantic integration of a large and growing corpus of plant genomics, phenomics and genetics data. The reference ontologies include the Plant Ontology, Plant Trait Ontology and the Plant Experimental Conditions Ontology developed by the Planteome project, along with the Gene Ontology, Chemical Entities of Biological Interest, Phenotype and Attribute Ontology, and others. The project also provides access to species-specific Crop Ontologies developed by various plant breeding and research communities from around the world. We provide integrated data on plant traits, phenotypes, and gene function and expression from 95 plant taxa, annotated with reference ontology terms. The Planteome project is developing a plant gene annotation platform; Planteome Noctua, to facilitate community engagement. All the Planteome ontologies are publicly available and are maintained at the Planteome GitHub site (https://github.com/Planteome) for sharing, tracking revisions and new requests. The annotated data are freely accessible from the ontology browser (http://browser.planteome.org/amigo) and our data repository
Report from the conference, ‘identifying obstacles to applying big data in agriculture’
Data-centric technology has not undergone widespread adoption in production agriculture but could address global needs for food security and farm profitability. Participants in the U.S. Department of Agriculture (USDA) National Institute for Food and Agriculture (NIFA) funded conference, “Identifying Obstacles to Applying Big Data in Agriculture,” held in Houston, TX, in August 2018, defined detailed scenarios in which on-farm decisions could benefit from the application of Big Data. The participants came from multiple academic fields, agricultural industries and government organizations and, in addition to defining the scenarios, they identified obstacles to implementing Big Data in these scenarios as well as potential solutions. This communication is a report on the conference and its outcomes. Two scenarios are included to represent the overall key findings in commonly identified obstacles and solutions: “In-season yield prediction for real-time decision-making”, and “Sow lameness.” Common obstacles identified at the conference included error in the data, inaccessibility of the data, unusability of the data, incompatibility of data generation and processing systems, the inconvenience of handling the data, the lack of a clear return on investment (ROI) and unclear ownership. Less common but valuable solutions to common obstacles are also noted
Detection and outcome of occult leptomeningeal disease in diffuse large B-cell lymphoma and Burkitt lymphoma
The benefit of intrathecal therapy and systemic rituximab on the outcome of diffuse large B-cell lymphoma at risk of central nervous system disease is controversial. Furthermore, the effect of intrathecal treatment and rituximab in diffuse large B-cell and Burkitt lymphoma with occult leptomeningeal disease detected by flow cytometry at diagnosis is unknown. Untreated diffuse large B-cell (n=246) and Burkitt (n=80) lymphoma at clinical risk of central nervous system disease and having had pre-treatment cerebrospinal fluid were analyzed by flow cytometry and cytology. Spinal fluid involvement was detected by flow cytometry alone (occult) in 33 (13%) diffuse large B-cell and 9 (11%) Burkitt lymphoma patients, and detected by cytology in 11 (4.5%) and 5 (6%) patients, respectively. Diffuse large B-cell lymphoma with occult spinal fluid involvement had poorer survival (P=0.0001) and freedom from central nervous system relapse (P<0.0001) compared to negative cases. Burkitt lymphoma with occult spinal fluid involvement had an inferior freedom from central nervous system relapse (P=0.026) but not survival. The amount of intrathecal chemotherapy was quantitatively associated with survival in diffuse large B-cell lymphoma with (P=0.02) and without (P=0.001) occult spinal fluid involvement. However, progression of systemic disease and not control of central nervous system disease was the principal cause of treatment failure. In diffuse large B-cell lymphoma, systemic rituximab was associated with improved freedom from central nervous system relapse (P=0.003) but not with survival. Our results suggest that patients at risk of central nervous system disease should be evaluated by flow cytometry and that intrathecal prophylaxis/therapy is beneficial
Debris Disks can Contaminate Mid-Infrared Exoplanet Spectra: Evidence for a Circumstellar Debris Disk around Exoplanet Host WASP-39
The signal from a transiting planet can be diluted by astrophysical
contamination. In the case of circumstellar debris disks, this contamination
could start in the mid-infrared and vary as a function of wavelength, which
would then change the observed transmission spectrum for any planet in the
system. The MIRI/LRS WASP-39b transmission spectrum shows an unexplained dip
starting at 10 m that could be caused by astrophysical
contamination. The spectral energy distribution displays excess flux at similar
levels to that which are needed to create the dip in the transmission spectrum.
In this article, we show that this dip is consistent with the presence of a
bright circumstellar debris disk, at a distance of 2 au. We discuss how a
circumstellar debris disk like that could affect the atmosphere of WASP-39b. We
also show that even faint debris disks can be a source of contamination in MIRI
exoplanet spectra.Comment: accepted to ApJ
Detection of carbon monoxide's 4.6 micron fundamental band structure in WASP-39b's atmosphere with JWST NIRSpec G395H
Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule
in giant planet atmospheres, and, along with water, is important for discerning
the oxygen and therefore carbon-to-oxygen ratio of these planets. The
fundamental absorption mode of CO has a broad double-branched structure
composed of many individual absorption lines from 4.3 to 5.1 m,
which can now be spectroscopically measured with JWST. Here we present a
technique for detecting the rotational sub-band structure of CO at medium
resolution with the NIRSpec G395H instrument. We use a single transit
observation of the hot Jupiter WASP-39b from the JWST Transiting Exoplanet
Community Early Release Science (JTEC ERS) program at the native resolution of
the instrument () to resolve the CO absorption structure. We
robustly detect absorption by CO, with an increase in transit depth of 264
68 ppm, in agreement with the predicted CO contribution from the best-fit
model at low resolution. This detection confirms our theoretical expectations
that CO is the dominant carbon-bearing molecule in WASP-39b's atmosphere, and
further supports the conclusions of low C/O and super-solar metallicities
presented in the JTEC ERS papers for WASP-39b.Comment: 11 pages, 5 figures, accepted for publication in ApJ
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