Radio Sources in the NCP Region Observed with the 21 Centimeter Array

We present a catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are taken from a 12 h observation made on 2013 April 13, with a frequency coverage from 75 to 175 MHz and an angular resolution of ~ 4 arcmin. The catalog includes flux densities at eight sub-bands across the 21CMA bandwidth and provides the in-band spectral indices for the detected sources. To reduce the complexity of interferometric imaging from the so-called "w" term and ionospheric effects, the present analysis are restricted to the east-west baselines within 1500 m only. The 624 radio sources are found within 5 degrees around the NCP down to ~ 0.1 Jy. Our source counts are compared, and also exhibit a good agreement, with deep low-frequency observations made recently with the GMRT and MWA. In particular, for fainter radio sources below ~ 1 Jy, we find a flattening trend of source counts towards lower frequencies. While the thermal noise (~0.4 mJy) is well controlled to below the confusion limit, the dynamical range (~10^4) and sensitivity of current 21CMA imaging is largely limited by calibration and deconvolution errors, especially the grating lobes of very bright sources, such as 3C061.1, in the NCP field which result from the regular spacings of the 21CMA. We note that particular attention should be paid to the extended sources, and their modeling and removals may constitute a large technical challenge for current EoR experiments. Our analysis may serve as a useful guide to design of next generation low-frequency interferometers like the Square Kilometre Array.Comment: 16 pages, 21 figures, 7 tables, 1 machine readable table, accepted for publication in Ap

Dean Melanie Leslie’s Office Hours

Join Dean Leslie and meet the new Vice Dean, Professor Felix Wu. Professor Wu is also a trademark and privacy law scholar and director of the Cardozo Data Law Initiative. His areas of expertise include cybersecurity, intellectual property and more. Come hear about his work, and about his new role as Vice Dean or use this opportunity to ask the dean about anything on your mind.https://larc.cardozo.yu.edu/event-invitations-2023/1028/thumbnail.jp

COMPARING LINEAR MIXED MODELS FOR PRELIMINARY YIELD TRIALS THAT FOLLOW AUGMENTED EXPERIMENTAL DESIGNS

COMPARING LINEAR MIXED MODELS FOR PRELIMINARY YIELD TRIALS THAT FOLLOW AUGMENTED EXPERIMENTAL DESIGNS Sudha Neupane Adhikari, Jixiang Wu, and Melanie Caffe-Treml Agronomy, Horticulture, and Plant Science Department, South Dakota State University, Brookings, SD 57007 Abstract Ineffective control of spatial variation when analyzing field trials data may lead to biased conclusions, which in turn could impact selection efficiency in plant breeding programs. In this study, a group of 78 oats breeding lines were evaluated in preliminary yield trials at four locations in South Dakota in 2015. Four linear mixed models (with and without row and column effects) were compared regarding reduction in error variance, heritability, and model relative efficiency for three traits (grain yield, test weight, and heading date). Results showed that accounting for row and column effects in the model was effective in reducing error variance and thus improved heritability and model relative efficiency for grain yield and heading date. Inclusion of row and column effects in the statistical models reduced the error variance by 20% and 14% for grain yield and heading date, respectively. For test weight, there was 11% reduction in error variance when only row effect was included in the model suggesting the absence of column effect. Results suggests that for traits affected by spatial trends, the inclusion of row and column effects in statistical models should improve the selection efficiency

Feedback modulation of cholesterol metabolism by the lipid-responsive non-coding RNA LeXis.

Liver X receptors (LXRs) are transcriptional regulators of cellular and systemic cholesterol homeostasis. Under conditions of excess cholesterol, LXR activation induces the expression of several genes involved in cholesterol efflux, facilitates cholesterol esterification by promoting fatty acid synthesis, and inhibits cholesterol uptake by the low-density lipoprotein receptor. The fact that sterol content is maintained in a narrow range in most cell types and in the organism as a whole suggests that extensive crosstalk between regulatory pathways must exist. However, the molecular mechanisms that integrate LXRs with other lipid metabolic pathways are incompletely understood. Here we show that ligand activation of LXRs in mouse liver not only promotes cholesterol efflux, but also simultaneously inhibits cholesterol biosynthesis. We further identify the long non-coding RNA LeXis as a mediator of this effect. Hepatic LeXis expression is robustly induced in response to a Western diet (high in fat and cholesterol) or to pharmacological LXR activation. Raising or lowering LeXis levels in the liver affects the expression of genes involved in cholesterol biosynthesis and alters the cholesterol levels in the liver and plasma. LeXis interacts with and affects the DNA interactions of RALY, a heterogeneous ribonucleoprotein that acts as a transcriptional cofactor for cholesterol biosynthetic genes in the mouse liver. These findings outline a regulatory role for a non-coding RNA in lipid metabolism and advance our understanding of the mechanisms that coordinate sterol homeostasis

Public Preferences and Willingness to Pay for a Net Zero NHS : a protocol for a discrete choice experiment in England and Scotland

We thank colleagues for their comments on the study design and questionnaire. We thank all members of the public who took part in the think aloud interviews. We also thank Dr Dwayne Boyers and Professor Jennie Macdiarmid for their review of the protocol and whose comments and suggestions were taken on board and incorporated in this manuscript. We want to thank two anonymous reviewers for their comments and suggested edits during the submission process.Peer reviewe

Nano Catalysts for Diesel Engine Emission Remediation

The objective of this project was to develop durable zeolite nanocatalysts with broader operating temperature windows to treat diesel engine emissions to enable diesel engine based equipment and vehicles to meet future regulatory requirements. A second objective was to improve hydrothermal durability of zeolite catalysts to at least 675 C. The results presented in this report show that we have successfully achieved both objectives. Since it is accepted that the first step in NO{sub x} conversion under SCR (selective catalytic reduction) conditions involves NO oxidation to NO{sub 2}, we reasoned that catalyst modification that can enhance NO oxidation at low-temperatures should facilitate NO{sub x} reduction at low temperatures. Considering that Cu-ZSM-5 is a more efficient catalyst than Fe-ZSM-5 at low-temperature, we chose to modify Cu-ZSM-5. It is important to point out that the poor low-temperature efficiency of Fe-ZSM-5 has been shown to be due to selective absorption of NH{sub 3} at low-temperatures rather than poor NO oxidation activity. In view of this, we also reasoned that an increased electron density on copper in Cu-ZSM-5 would inhibit any bonding with NH{sub 3} at low-temperatures. In addition to modified Cu-ZSM-5, we synthesized a series of new heterobimetallic zeolites, by incorporating a secondary metal cation M (Sc{sup 3+}, Fe{sup 3+}, In{sup 3+}, and La{sup 3+}) in Cu exchanged ZSM-5, zeolite-beta, and SSZ-13 zeolites under carefully controlled experimental conditions. Characterization by diffuse-reflectance ultra-violet-visible spectroscopy (UV-Vis), X-ray powder diffraction (XRD), extended X-ray absorption fine structure spectroscopy (EXAFS) and electron paramagnetic resonance spectroscopy (EPR) does not permit conclusive structural determination but supports the proposal that M{sup 3+} has been incorporated in the vicinity of Cu(II). The protocols for degreening catalysts, testing under various operating conditions, and accelerated aging conditions were provided by our collaborators at John Deere Power Systems. Among various zeolites reported here, CuFe-SSZ-13 offers the best NO{sub x} conversion activity in 150-650 C range and is hydrothermally stable when tested under accelerated aging conditions. It is important to note that Cu-SSZ-13 is now a commercial catalyst for NO{sub x} treatment on diesel passenger vehicles. Thus, our catalyst performs better than the commercial catalyst under fast SCR conditions. We initially focused on fast SCR tests to enable us to screen catalysts rapidly. Only the catalysts that exhibit high NO{sub x} conversion at low temperatures are selected for screening under varying NO{sub 2}:NO{sub x} ratio. The detailed tests of CuFe-SSZ-13 show that CuFe-SSZ-13 is more effective than commercial Cu-SSZ-13 even at NO{sub 2}:NO{sub x} ratio of 0.1. The mechanistic studies, employing stop-flow diffuse reflectance FTIR spectroscopy (DRIFTS), suggest that high concentration of NO{sup +}, generated by heterobimetallic zeolites, is probably responsible for their superior low temperature NO{sub x} activity. The results described in this report clearly show that we have successfully completed the first step in a new emission treatment catalyst which is synthesis and laboratory testing employing simulated exhaust. The next step in the catalyst development is engine testing. Efforts are in progress to obtain follow-on funding to carry out scale-up and engine testing to facilitate commercialization of this technology

A structural investigation of novel thiophene-functionalized BEDT-TTF donors for application as organic field-effect transistors

Three new unsymmetrical thiophene-functionalized bisIJethylenedithio)tetrathiafulvalene (BEDT-TTF) donors (1–3) have been synthesized, characterised and examined as semiconducting materials for organic field-effect transistor (OFET) devices. The X-ray crystal structures of (1) and (2) reveal both neutral donors pack as dimers with lateral S⋯S contacts. For (1) the molecules are co-facially stacked in a head-to-tail manner with some degree of latitudinal slippage. A device prepared from a crystalline thin film of (1) deposited on unmodified silicon wafer substrate displays a mobility of 5.9 × 10−3 cm2 V−1 s−1 with an on/off ratio of 11. The shorter CH2 linker in (2) results in poorer orbital overlap, likely due to significant longitudinal and latitudinal slippage between molecules in the crystal lattice. As a consequence, no field-effect response was observed for the device fabricated from (2)

BCL6 enables Ph+ acute lymphoblastic leukaemia cells to survive BCR-ABL1 kinase inhibition.

Tyrosine kinase inhibitors (TKIs) are widely used to treat patients with leukaemia driven by BCR-ABL1 (ref. 1) and other oncogenic tyrosine kinases. Recent efforts have focused on developing more potent TKIs that also inhibit mutant tyrosine kinases. However, even effective TKIs typically fail to eradicate leukaemia-initiating cells (LICs), which often cause recurrence of leukaemia after initially successful treatment. Here we report the discovery of a novel mechanism of drug resistance, which is based on protective feedback signalling of leukaemia cells in response to treatment with TKI. We identify BCL6 as a central component of this drug-resistance pathway and demonstrate that targeted inhibition of BCL6 leads to eradication of drug-resistant and leukaemia-initiating subclones