185 research outputs found
A simulation suite for readout with SMuRF tone-tracking electronics
We present the details of a simulation suite for modeling the effects of
readout with SLAC Microresonator RF (SMuRF) electronics. The SMuRF electronics
are a warm readout and control system for use with superconducting microwave
resonator-based detector systems. The system has been used with the BICEP/Keck
program and will be used on the upcoming Simons Observatory and BICEP Array
experiments. This simulation suite is a software implementation of the main
SMuRF algorithms for offline analysis, modeling, and study. The
firmware-implemented algorithms for calibration, resonator frequency
estimation, and tone tracking present sources of potential bias or errors if
not modeled properly. The simulator takes as input true detector signal,
realistic resonator properties, and SMuRF-related user-controlled readout
settings. It returns the final flux ramp-demodulated output of a detector
timestream as would be passed to the experiment data acquisition system,
enabling the analysis of the impact of readout-related parameters on the final
science data. It is publicly available in Python with accompanying Jupyter
notebooks for user tutorials.Comment: 12 pages + references, 7 figures. Proceedings for SPIE Astronomical
Telescopes and Instrumentation 2022. Code at
https://github.com/cyndiayu/babysmur
Voluntary organizations and society–military relations in contemporary Russia
The 2014 crisis in Ukraine has refocused attention on Russia as a European security actor. Despite showing renewed military capability, compared to the post-Soviet period, Russian society–military relations have remained the same. This relationship (between society and the security organs) provides the key context for assessing security. Analysis of everyday militarization and the role of voluntary organizations (such as DOSAAF [Dobrovol'noe obshchestvo sodeistviya armii, aviatsii i flotu] and Nashi [Molodezhnoe demokraticheskoe antifashistskoe dvizheni]) in supporting the military can provide an important insight into Russian behaviour as a security actor. These organizations generate a pro-military outlook and at the same time provide training and activities, thus contributing to military effectiveness by developing the competency of young people prior to military service as well as increasing public knowledge of military affairs. However, strong support for the military, a lack of independent information, and an absence of a shared vision on how society–military relations should be developed and also represent political challenges in terms of everyday militarization. This dynamic is important for understanding both Russia's security posture and wider security implications for Europe
Targeting transcription regulation in cancer with a covalent CDK7 inhibitor
Tumour oncogenes include transcription factors that co-opt the general transcriptional machinery to sustain the oncogenic state, but direct pharmacological inhibition of transcription factors has so far proven difficult. However, the transcriptional machinery contains various enzymatic cofactors that can be targeted for the development of new therapeutic candidates, including cyclin-dependent kinases (CDKs). Here we present the discovery and characterization of a covalent CDK7 inhibitor, THZ1, which has the unprecedented ability to target a remote cysteine residue located outside of the canonical kinase domain, providing an unanticipated means of achieving selectivity for CDK7. Cancer cell-line profiling indicates that a subset of cancer cell lines, including human T-cell acute lymphoblastic leukaemia (T-ALL), have exceptional sensitivity to THZ1. Genome-wide analysis in Jurkat T-ALL cells shows that THZ1 disproportionally affects transcription of RUNX1 and suggests that sensitivity to THZ1 may be due to vulnerability conferred by the RUNX1 super-enhancer and the key role of RUNX1 in the core transcriptional regulatory circuitry of these tumour cells. Pharmacological modulation of CDK7 kinase activity may thus provide an approach to identify and treat tumour types that are dependent on transcription for maintenance of the oncogenic state.National Institutes of Health (U.S.) (Grant HG002668)National Institutes of Health (U.S.) (Grant CA109901
High power Q-switched thulium doped fibre laser using carbon nanotube polymer composite saturable absorber
We have proposed and demonstrated a Q-switched Thulium doped bre laser (TDFL) with a ‘Yin-Yang’ all- bre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear ampli ed loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped bre laser
Cross-correlation of CMB polarization lensing with High-z submillimeter Herschel-ATLAS galaxies
We report a 4.8σ measurement of the cross-correlation signal between the cosmic microwave background (CMB) lensing convergence reconstructed from measurements of the CMB polarization made by the Polarbear experiment and the infrared-selected galaxies of the Herschel-ATLAS survey. This is the first measurement of its kind
The Simons Observatory microwave SQUID multiplexing detector module design
Advances in cosmic microwave background (CMB) science depend on increasing
the number of sensitive detectors observing the sky. New instruments deploy
large arrays of superconducting transition-edge sensor (TES) bolometers tiled
densely into ever larger focal planes. High multiplexing factors reduce the
thermal loading on the cryogenic receivers and simplify their design. We
present the design of focal-plane modules with an order of magnitude higher
multiplexing factor than has previously been achieved with TES bolometers. We
focus on the novel cold readout component, which employs microwave SQUID
multiplexing (mux). Simons Observatory will use 49 modules containing
60,000 bolometers to make exquisitely sensitive measurements of the CMB. We
validate the focal-plane module design, presenting measurements of the readout
component with and without a prototype detector array of 1728
polarization-sensitive bolometers coupled to feedhorns. The readout component
achieves a yield and a 910 multiplexing factor. The median white noise
of each readout channel is 65 . This impacts the
projected SO mapping speed by , which is less than is assumed in the
sensitivity projections. The results validate the full functionality of the
module. We discuss the measured performance in the context of SO science
requirements, which are exceeded.Comment: Accepted to The Astrophysical Journa
The POLARBEAR-2 and Simons Array Focal Plane Fabrication Status
We present on the status of POLARBEAR-2 A (PB2-A) focal plane fabrication.
The PB2-A is the first of three telescopes in the Simon Array (SA), which is an
array of three cosmic microwave background (CMB) polarization sensitive
telescopes located at the POLARBEAR (PB) site in Northern Chile. As the
successor to the PB experiment, each telescope and receiver combination is
named as PB2-A, PB2-B, and PB2-C. PB2-A and -B will have nearly identical
receivers operating at 90 and 150 GHz while PB2-C will house a receiver
operating at 220 and 270 GHz. Each receiver contains a focal plane consisting
of seven close-hex packed lenslet coupled sinuous antenna transition edge
sensor bolometer arrays. Each array contains 271 di-chroic optical pixels each
of which have four TES bolometers for a total of 7588 detectors per receiver.
We have produced a set of two types of candidate arrays for PB2-A. The first we
call Version 11 (V11) and uses a silicon oxide (SiOx) for the transmission
lines and cross-over process for orthogonal polarizations. The second we call
Version 13 (V13) and uses silicon nitride (SiNx) for the transmission lines and
cross-under process for orthogonal polarizations. We have produced enough of
each type of array to fully populate the focal plane of the PB2-A receiver. The
average wirebond yield for V11 and V13 arrays is 93.2% and 95.6% respectively.
The V11 arrays had a superconducting transition temperature (Tc) of 452 +/- 15
mK, a normal resistance (Rn) of 1.25 +/- 0.20 Ohms, and saturations powers of
5.2 +/- 1.0 pW and 13 +/- 1.2 pW for the 90 and 150 GHz bands respectively. The
V13 arrays had a superconducting transition temperature (Tc) of 456 +/-6 mK, a
normal resistance (Rn) of 1.1 +/- 0.2 Ohms, and saturations powers of 10.8 +/-
1.8 pW and 22.9 +/- 2.6 pW for the 90 and 150 GHz bands respectively
The changing role of china in the global illegal cigarette trade
This study explores the history of the illegal production, distribution, and smuggling of cigarettes in mainland China. Data were obtained from a content analysis of 931 media reports retrieved from LexisNexis for the time period 1975 until 2010, and from other open sources. The illegal cigarette trade first emerged in the form of violations of state tobacco monopoly regulations. In the course of the restructuring of the legal tobacco sector, which occurred under external political pressure to open the Chinese market to foreign competition, an illegal cigarette industry emerged which at first primarily produced fake Chinese brand cigarettes for the domestic black market. At the same time, China became a destination country for smuggled genuine Western brand cigarettes. It was only after effective crackdowns against cigarette smuggling and domestic distribution channels in the late 1990s that the Chinese illegal cigarette industry shifted to exporting large numbers of counterfeit Western brand cigarettes to black markets abroad. China’s current role as a leading supplier of counterfeit cigarettes is a result of the contradictions of the economic reform process and of external licit and illicit forces that worked toward opening up the Chinese tobacco sector to the outside world
The landscape of inherited and de novo copy number variants in a plasmodium falciparum genetic cross
<p>Abstract</p> <p>Background</p> <p>Copy number is a major source of genome variation with important evolutionary implications. Consequently, it is essential to determine copy number variant (CNV) behavior, distributions and frequencies across genomes to understand their origins in both evolutionary and generational time frames. We use comparative genomic hybridization (CGH) microarray and the resolution provided by a segregating population of cloned progeny lines of the malaria parasite, <it>Plasmodium falciparum</it>, to identify and analyze the inheritance of 170 genome-wide CNVs.</p> <p>Results</p> <p>We describe CNVs in progeny clones derived from both Mendelian (i.e. inherited) and non-Mendelian mechanisms. Forty-five CNVs were present in the parent lines and segregated in the progeny population. Furthermore, extensive variation that did not conform to strict Mendelian inheritance patterns was observed. 124 CNVs were called in one or more progeny but in neither parent: we observed CNVs in more than one progeny clone that were not identified in either parent, located more frequently in the telomeric-subtelomeric regions of chromosomes and singleton <it>de novo </it>CNVs distributed evenly throughout the genome. Linkage analysis of CNVs revealed dynamic copy number fluctuations and suggested mechanisms that could have generated them. Five of 12 previously identified expression quantitative trait loci (eQTL) hotspots coincide with CNVs, demonstrating the potential for broad influence of CNV on the transcriptional program and phenotypic variation.</p> <p>Conclusions</p> <p>CNVs are a significant source of segregating and <it>de novo </it>genome variation involving hundreds of genes. Examination of progeny genome segments provides a framework to assess the extent and possible origins of CNVs. This segregating genetic system reveals the breadth, distribution and dynamics of CNVs in a surprisingly plastic parasite genome, providing a new perspective on the sources of diversity in parasite populations.</p
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