The Pan-STARRS1 Database and Data Products Flewelling, H. A.; Magnier, E. A.; Chambers, K. C. ...
The Astrophysical journal. Supplement series,
11/2020, Letnik:
251, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
This paper describes the organization of the database and the catalog data products from the Pan-STARRS1 3
π
Steradian Survey. The catalog data products are available in the form of an ...SQL-based relational database from MAST, the Mikulski Archive for Space Telescopes at STScI. The database is described in detail, including the construction of the database, the provenance of the data, the schema, and how the database tables are related. Examples of queries for a range of science goals are included.
Low dose electron imaging applications such as electron cryo-microscopy are now benefitting from the improved performance and flexibility of recently introduced electron imaging detectors in which ...electrons are directly incident on backthinned CMOS sensors. There are currently three commercially available detectors of this type: the Direct Electron DE-20, the FEI Falcon II and the Gatan K2 Summit. These have different characteristics and so it is important to compare their imaging properties carefully with a view to optimise how each is used. Results at 300keV for both the modulation transfer function (MTF) and the detective quantum efficiency (DQE) are presented. Of these, the DQE is the most important in the study of radiation sensitive samples where detector performance is crucial. We find that all three detectors have a better DQE than film. The K2 Summit has the best DQE at low spatial frequencies but with increasing spatial frequency its DQE falls below that of the Falcon II.
•Three direct electron detectors offer better DQE than film at 300keV.•Recorded 300keV electron events on the detectors have very similar Landau distributions.•The Gatan K2 Summit detector has the highest DQE at low spatial frequency.•The FEI Falcon II detector has the highest DQE beyond one half the Nyquist frequency.•The Direct Electron DE-20 detector has the fastest data acquisition rate.
Plasma cell leukemia (PCL) is an aggressive and rare hematological malignancy that originates either as primary disease (pPCL) or as a secondary leukemic transformation (sPCL) of multiple myeloma ...(MM). We report here the genetic aberrations and survival of 80 patients with pPCL or sPCL and make comparisons with 439 cases of MM. pPCL presents a decade earlier than sPCL (54.7 vs 65.3 years) and is associated with longer median overall survival (11.1 vs 1.3 months; P<0.001). 14q32 (IgH) translocations are highly prevalent in both sPCL and pPCL (82-87%); in pPCL IgH translocations almost exclusively involve 11q13 (CCND1), supporting a central etiological role, while in sPCL multiple partner oncogenes are involved, including 11q13, 4p16 (FGFR3/MMSET) and 16q23 (MAF), recapitulating MM. Both show ubiquitous inactivation of TP53 (pPCL 56%; sPCL 83%) by coding mutation or 17p13 deletion; complemented by p14ARF epigenetic silencing in sPCL (29%). Both show frequent N-RAS or K-RAS mutation. Poor survival in pPCL was predicted by MYC translocation (P=0.006). Survival in sPCL was consistently short. Overall pPCL and sPCL are different disorders with distinct natural histories, genetics and survival.
Topical microbicides, used by women to prevent the transmission of HIV and other sexually transmitted infections are urgently required. Dendrimers are highly branched nanoparticles being developed as ...microbicides. However, the anti-HIV and HSV structure-activity relationship of dendrimers comprising benzyhydryl amide cores and lysine branches, and a comprehensive analysis of their broad-spectrum anti-HIV activity and mechanism of action have not been published.
Dendrimers with optimized activity against HIV-1 and HSV-2 were identified with respect to the number of lysine branches (generations) and surface groups. Antiviral activity was determined in cell culture assays. Time-of-addition assays were performed to determine dendrimer mechanism of action. In vivo toxicity and HSV-2 inhibitory activity were evaluated in the mouse HSV-2 susceptibility model. Surface groups imparting the most potent inhibitory activity against HIV-1 and HSV-2 were naphthalene disulfonic acid (DNAA) and 3,5-disulfobenzoic acid exhibiting the greatest anionic charge and hydrophobicity of the seven surface groups tested. Their anti-HIV-1 activity did not appreciably increase beyond a second-generation dendrimer while dendrimers larger than two generations were required for potent anti-HSV-2 activity. Second (SPL7115) and fourth generation (SPL7013) DNAA dendrimers demonstrated broad-spectrum anti-HIV activity. However, SPL7013 was more active against HSV and blocking HIV-1 envelope mediated cell-to-cell fusion. SPL7013 and SPL7115 inhibited viral entry with similar potency against CXCR4-(X4) and CCR5-using (R5) HIV-1 strains. SPL7013 was not toxic and provided at least 12 h protection against HSV-2 in the mouse vagina.
Dendrimers can be engineered with optimized potency against HIV and HSV representing a unique platform for the controlled synthesis of chemically defined multivalent agents as viral entry inhibitors. SPL7013 is formulated as VivaGel(R) and is currently in clinical development to provide protection against HIV and HSV. SPL7013 could also be combined with other microbicides.
Grapevine salt tolerance Zhou‐Tsang, A.; Wu, Y.; Henderson, S.W. ...
Australian journal of grape and wine research,
April 2021, 2021-04-00, 20210401, Letnik:
27, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Salinity, which is predominantly an issue for agricultural systems in arid and semi‐arid regions, has the potential to impair grape production and wine quality, and its impact on the grape and wine ...industries is predicted to increase with climate change. Research on the physiological and molecular changes that occur in salt‐affected vines has unveiled complex osmotic and ionic responses that include oxidative stress, water loss, photoinhibition, growth inhibition and necrosis. Proposed salt tolerance mechanisms include elevated antioxidant production, hydric regulation and salt exclusion from shoots and berries. These later of these mechanisms is found in certain Vitis genotypes that, when grafted as rootstocks, can protect fruit‐bearing scions from accumulating significant amounts of saline ions from soils, most notably through the presence of specific transport proteins that are involved in regulating the transfer of ions from root to shoot via the xylem. Significant gaps in knowledge remain, however, regarding salt tolerance mechanisms for Vitis species, with many mechanisms inferred from other species or documented only at the level of gene expression. A better understanding of the mechanisms that confer salt tolerance in Vitis species is needed to improve the production of new germplasm that is locally adapted and better suited to the challenges of a changing climate. Hence, this review covers the current knowledge on the characteristics that are associated with salt damage and tolerance in grapevine cultivars and rootstocks and highlights possible future avenues that will enable development of new options for the industry to combat salinity.
High-energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. To increase the energy of the particles ...or to reduce the size of the accelerator, new acceleration schemes need to be developed. Plasma wakefield acceleration
, in which the electrons in a plasma are excited, leading to strong electric fields (so called 'wakefields'), is one such promising acceleration technique. Experiments have shown that an intense laser pulse
or electron bunch
traversing a plasma can drive electric fields of tens of gigavolts per metre and above-well beyond those achieved in conventional radio-frequency accelerators (about 0.1 gigavolt per metre). However, the low stored energy of laser pulses and electron bunches means that multiple acceleration stages are needed to reach very high particle energies
. The use of proton bunches is compelling because they have the potential to drive wakefields and to accelerate electrons to high energy in a single acceleration stage
. Long, thin proton bunches can be used because they undergo a process called self-modulation
, a particle-plasma interaction that splits the bunch longitudinally into a series of high-density microbunches, which then act resonantly to create large wakefields. The Advanced Wakefield (AWAKE) experiment at CERN
uses high-intensity proton bunches-in which each proton has an energy of 400 gigaelectronvolts, resulting in a total bunch energy of 19 kilojoules-to drive a wakefield in a ten-metre-long plasma. Electron bunches are then injected into this wakefield. Here we present measurements of electrons accelerated up to two gigaelectronvolts at the AWAKE experiment, in a demonstration of proton-driven plasma wakefield acceleration. Measurements were conducted under various plasma conditions and the acceleration was found to be consistent and reliable. The potential for this scheme to produce very high-energy electron bunches in a single accelerating stage
means that our results are an important step towards the development of future high-energy particle accelerators
.
There is increasing evidence relating thalamic changes to the generation and/or maintenance of neuropathic pain. We have recently reported that neuropathic orofacial pain is associated with altered ...thalamic anatomy, biochemistry, and activity, which may result in disturbed thalamocortical oscillatory circuits. Despite this evidence, it is possible that these thalamic changes are not responsible for the presence of pain per se, but result as a consequence of the injury. To clarify this subject, we compared brain activity and biochemistry in 12 people with below-level neuropathic pain after complete thoracic spinal cord injury with 11 people with similar injuries and no neuropathic pain and 21 age- and gender-matched healthy control subjects. Quantitative arterial spinal labelling was used to measure thalamic activity, and magnetic resonance spectroscopy was used to determine changes in neuronal variability quantifying N-acetylaspartate and alterations in inhibitory function quantifying gamma amino butyric acid. This study revealed that the presence of neuropathic pain is associated with significant changes in thalamic biochemistry and neuronal activity. More specifically, the presence of neuropathic pain after spinal cord injury is associated with significant reductions in thalamic N-acetylaspartate, gamma amino butyric acid content, and blood flow in the region of the thalamic reticular nucleus. Spinal cord injury on its own did not account for these changes. These findings support the hypothesis that neuropathic pain is associated with altered thalamic structure and function, which may disturb central processing and play a key role in the experience of neuropathic pain.
Recent progress in detector design has created the need for a careful side-by-side comparison of the modulation transfer function (MTF) and resolution-dependent detective quantum efficiency (DQE) of ...existing electron detectors with those of detectors based on new technology. We present MTF and DQE measurements for four types of detector: Kodak SO-163 film, TVIPS 224 charge coupled device (CCD) detector, the Medipix2 hybrid pixel detector, and an experimental direct electron monolithic active pixel sensor (MAPS) detector. Film and CCD performance was measured at 120 and 300keV, while results are presented for the Medipix2 at 120keV and for the MAPS detector at 300keV. In the case of film, the effects of electron backscattering from both the holder and the plastic support have been investigated. We also show that part of the response of the emulsion in film comes from light generated in the plastic support. Computer simulations of film and the MAPS detector have been carried out and show good agreement with experiment. The agreement enables us to conclude that the DQE of a backthinned direct electron MAPS detector is likely to be equal to, or better than, that of film at 300keV.
Direct Electron Detectors McMullan, G; Faruqi, A R; Henderson, R
Methods in enzymology,
2016, Letnik:
579
Journal Article
Recenzirano
Direct electron detectors have played a key role in the recent increase in the power of single-particle electron cryomicroscopy (cryoEM). In this chapter, we summarize the background to these recent ...developments, give a practical guide to their optimal use, and discuss future directions.
PDF
