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2021 ◽  
Author(s):  
Kasen K Riemersma ◽  
Brittany E Grogan ◽  
Amanda Kita-Yarbro ◽  
Gunnar E Jeppson ◽  
David H O'Connor ◽  
...  

SARS-CoV-2 variant B.1.617.2 (delta) is associated with higher viral loads [1] and increased transmissibility relative to other variants, as well as partial escape from polyclonal and monoclonal antibodies [2]. The emergence of the delta variant has been associated with increasing case counts and test-positivity rates, indicative of rapid community spread. Since early July 2021, SARS-CoV-2 cases in the United States have increased coincident with delta SARS-CoV-2 becoming the predominant lineage nationwide [3]. Understanding how and why the virus is spreading in settings where there is high vaccine coverage has important public health implications. It is particularly important to assess whether vaccinated individuals who become infected can transmit SARS-CoV-2 to others. In Wisconsin, a large local contract laboratory provides SARS-CoV-2 testing for multiple local health departments, providing a single standard source of data using the same assay to measure virus burdens in test-positive cases. This includes providing high-volume testing in Dane County, a county with extremely high vaccine coverage. These PCR-based tests provide semi-quantitative information about the viral load, or amount of SARS-CoV-2 RNA, in respiratory specimens. Here we use this viral load data to compare the amount of SARS-CoV-2 present in test-positive specimens from people who self-report their vaccine status and date of final immunization, during a period in which the delta variant became the predominant circulating variant in Wisconsin. We find no difference in viral loads when comparing unvaccinated individuals to those who have vaccine "breakthrough" infections. Furthermore, individuals with vaccine breakthrough infections frequently test positive with viral loads consistent with the ability to shed infectious viruses. Our results, while preliminary, suggest that if vaccinated individuals become infected with the delta variant, they may be sources of SARS-CoV-2 transmission to others.


2021 ◽  
Vol 14 (1-2021) ◽  
pp. 229-231
Author(s):  
Hellmut Wollmann

In covering 16 European countries, the 500 pages book provides a broad overview (“stocktaking”) of the development of evaluation in Europe focusing on the institutions and actors initiating, involved in, and using evaluation. The book is made up of the (conceptually reflected) introductory and (aptly) summarizing chapters written by the editors and the (substantive data-rich) country reports written by some 20 country experts. While all countries show a “macro” trend in the convergent rise of evaluation (particularly with regard to government-commissioned evaluation and of “professionalization” of evaluators), the countries show marked variance (country-specific “starting conditions”, dynamics (“waves”), institutional forms, etc.). The book can be deemed a valuable update and extension of the previous “stocktaking” of evaluation in the “International Atlas of Evaluation” edited by Jan-Eric Furubo, Ray C. Rist and Rolf Sandahl in 2002. It has the potential of being a standard source and handbook in evaluation-related teaching, research, and practice for many years.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hongzhou Wang ◽  
Jennifer H. Simpson ◽  
Madison E. Kotra ◽  
Yuanting Zhu ◽  
Saumya Wickramasinghe ◽  
...  

Abstract Objective Ribonucleic acids (RNA) are involved in many cellular functions. In general, RNA is made up by only four different ribonucleotides. The modifications of RNA (epitranscriptome) can greatly enhance the structural diversity of RNA, which in turn support some of the RNA functions. To determine whether the epitranscriptome of a specific probiotic is associated with its adaptation to the source of energy, Lactobacillus agilis (YZ050) was selected as a model and its epitranscriptome was profiled and compared by using mass spectrometry. Results The L. agilis epitranscriptome (minus rRNA modifications) consists of 17 different RNA modifications. By capturing the L. agilis cells during exponential growth, reproducible profiling was achieved. In a comparative study, the standard source of energy (glucose) in the medium was substituted by a prebiotic inulin, and a downward trend in the L. agilis epitranscriptome was detected. This marks the first report on a system-wide variation of a bacterial epitranscriptome that resulted from adapting to an alternative energy source. No correlation was found between the down-regulated RNA modifications and the expression level of corresponding writer genes. Whereas, the expression level of a specific exonuclease gene, RNase J1, was detected to be higher in cells grown on inulin.


Metrologia ◽  
2020 ◽  
Vol 57 (6) ◽  
pp. 065024
Author(s):  
Yuri Nakazawa ◽  
Kenji Godo ◽  
Kazuki Niwa ◽  
Tatsuya Zama ◽  
Yoshiki Yamaji ◽  
...  

2020 ◽  
Vol 13 (5) ◽  
pp. 2473-2480 ◽  
Author(s):  
Young Ro Lee ◽  
Yi Ji ◽  
David J. Tanner ◽  
L. Gregory Huey

Abstract. Most I−-CIMSs (iodide chemical ionization mass spectrometers) for measurement of atmospheric trace gases utilize a radioactive ion source with an initial activity of 10 or 20 mCi of 210Po. In this work, we characterize a 210Po ion source with an initial activity of 1.5 mCi that can be easily constructed from commercially available components. The low level of radioactive activity of this source significantly reduces regulatory burden with storage and shipping relative to higher-activity sources. We compare the sensitivity of the low-activity source (LAS) to a standard 20 mCi source, as a function of carrier gas flow and flow tube pressure, for peroxyacetyl nitrate (PAN), formic acid (HCO2H), molecular chlorine (Cl2) and nitryl chloride (ClNO2), using an I−-CIMS. The LAS provides 2 to 5 times less sensitivity than that of the standard source even though the ratio of activity is approximately 13. However, detection limits of less than 2 pptv for the tested compounds are achieved for integration times on the order of a minute. The sensitivity of the LAS is less dependent on the magnitude of the carrier gas than a standard source. In addition, the LAS provides maximum sensitivity at relatively low carrier gas flows. Finally, we demonstrate that the LAS can be used to measure PAN in the remote atmosphere from an aircraft by showing data obtained on the NASA DC-8 during the Atmospheric Tomography (ATom) mission. In summary, the LAS may be an excellent substitute for a standard ion source in short-term field deployments.


2019 ◽  
Author(s):  
Young Ro Lee ◽  
Yi Ji ◽  
David J. Tanner ◽  
L. Gregory Huey

Abstract. Most I--CIMS (iodide-chemical ionization mass spectrometers) for measurement of atmospheric trace gases utilize a radioactive ion source with an initial activity of 10 or 20 mCi of 210Po. In this work, we characterize a 210Po ion source with an initial activity of 1.5 mCi that can be easily constructed from commercially available components. The low level of radioactive activity of this source significantly reduces complications with storage and shipping relative to higher activity sources. We compare the sensitivity of the low activity source (LAS) to a standard 20 mCi source, as a function of carrier gas flow and flow tube pressure, for peroxyacetyl nitrate (PAN), formic acid (HCO2H) molecular chlorine (Cl2), and nitryl chloride (ClNO2) using an I--CIMS. The LAS provides 2 to 5 times less sensitivity than that of the standard source even though the ratio of activity is approximately 13. However, detection limits of less than 2 pptv for the tested compounds are achieved for integration times of the order of a minute. The sensitivity of the LAS is less dependent on the magnitude of the carrier gas than a standard source. In addition, the LAS provides maximum sensitivity at relatively low carrier gas flows. Finally, we demonstrate that the LAS can be used to measure PAN in the remote atmosphere from an aircraft by showing data obtained on the NASA DC-8 during the Atmospheric Tomography (ATom) mission. In summary, the LAS may be an excellent substitute for a standard ion source in some field applications.


2019 ◽  
pp. 154-177
Author(s):  
Stefan Kamola

Rashid al-Din fell from royal favour and was executed in 1318. This chapter traces the period of his decline and the years immediately following his death to show how contemporary historians responded to his enormous historical impact. The works of Wassaf, Qashani, and Hamd Allah Mustaufi reveal three images of Rashid al-Din that have persisted through modern scholarship, but each of these men was impacted by personal circumstances to produce a particular portrait of Rashid al-Din. This chapter contrasts accounts of specific events in the year 1312 as presented by Wassaf and Qashani to show how they created two visions of Rashid al-Din’s activity at court. Hamd Allah Mustaufi created a posthumous portrait of Rashid al-Din as a noble civil servant that became a standard source for later writers.


Author(s):  
Anthony Duncan ◽  
Michel Janssen

This is the first of two volumes on the genesis of quantum mechanics. It covers the key developments in the period 1900–1923 that provided the scaffold on which the arch of modern quantum mechanics was built in the period 1923–1927 (covered in the second volume). After tracing the early contributions by Planck, Einstein, and Bohr to the theories of black‐body radiation, specific heats, and spectroscopy, all showing the need for drastic changes to the physics of their day, the book tackles the efforts by Sommerfeld and others to provide a new theory, now known as the old quantum theory. After some striking initial successes (explaining the fine structure of hydrogen, X‐ray spectra, and the Stark effect), the old quantum theory ran into serious difficulties (failing to provide consistent models for helium and the Zeeman effect) and eventually gave way to matrix and wave mechanics. Constructing Quantum Mechanics is based on the best and latest scholarship in the field, to which the authors have made significant contributions themselves. It breaks new ground, especially in its treatment of the work of Sommerfeld and his associates, but also offers new perspectives on classic papers by Planck, Einstein, and Bohr. Throughout the book, the authors provide detailed reconstructions (at the level of an upper‐level undergraduate physics course) of the cental arguments and derivations of the physicists involved. All in all, Constructing Quantum Mechanics promises to take the place of older books as the standard source on the genesis of quantum mechanics.


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