The onset of X-ray emission in young stellar objects: a Chandra observation of the Serpens star-forming region

AIMS: To study the properties of X-ray emissions from young stellar objects (YSOs), through their evolution from Class I to Class III and determine whether Class 0 protostars emit in X-rays. METHODS: A deep Chandra X-ray observation of the Serpens star-forming region was obtained. The Serpens Cloud Core is ideally suited for this type of investigation, being populated by a dense and extremely young cluster whose members are found in all different evolutionary stages, including six well studied Class 0 sources. RESULTS: None of the six Class 0 protostars is detected in our observations, excluding the presence of sources with X-ray luminosities > 0.4 10^30 erg/s (for column densities of the order of 4 10^{23} cm^-2, or A_V ~ 200). A total of 85 X-ray sources are detected and the light curves and spectra of 35 YSOs are derived. There is a clear trend of decreasing absorbing column densities as one moves from Class I to Class III sources, and, possibly, evidence of decreasing plasma temperatures, too. We observe a strong, long-duration, flare from a Class II low-mass star, for which we derive a flaring loop length of the order of 20 stellar radii. We interpret the flaring event as originating from a magnetic flux tube connecting the star to its circumstellar disk. The presence of such a disk is supported by the detection, in the spectrum of this star, of 6.4 keV Fe fluorescent emission.Comment: Accepted for publication in A&

Extragalactic H_2O masers and X-ray absorbing column densities

Having conducted a search for the 22 GHz water vapor line towards galaxies with nuclear activity, large nuclear column densities or high infrared luminosities, we present H_2O spectra for NGC2273, UGC5101 and NGC3393 with isotropic luminosities of 7, 1500, and 400 L_sun. The H_2O maser in UGC5101 is by far the most luminous yet found in an ultraluminous infrared galaxy. NGC3393 reveals the classic spectrum of a `disk maser', represented by three distinct groups of Doppler components. As in all other known cases except NGC4258, the rotation velocity of the putative masing disk is well below 1000 km/s. Based on the literature and archive data, X-ray absorbing column densities are compiled for the 64 galaxies with reported maser sources beyond the Magellanic Clouds. For NGC2782 and NGC5728, we present Chandra archive data that indicate the presence of an active galactic nucleus in both galaxies. The correlation between absorbing column and H_2O emission is analyzed. There is a striking difference between kilo- and megamasers with megamasers being associated with higher column densities. All kilomasers (L_H_2O < 10 L_sun) except NGC2273 and NGC5194 are Compton-thin, i.e. their absorbing columns are < 10^24 cm^-2. Among the H_2O megamasers, 50% arise from Compton-thick and 85% from heavily obscured (> 10^23 cm^-2) active galactic nuclei. These values are not larger but consistent with those from samples of Seyfert 2 galaxies not selected on the basis of maser emission. The similarity in column densities can be explained by small deviations in position between maser spots and nuclear X-ray source and a high degree of clumpiness in the circumnuclear interstellar medium.Comment: 16 pages, 7 figures, 5 tables. Accepted for publication in A&

Development of an amplicon-based sequencing approach in response to the global emergence of mpox

The 2022 multicountry mpox outbreak concurrent with the ongoing Coronavirus Disease 2019 (COVID-19) pandemic further highlighted the need for genomic surveillance and rapid pathogen whole-genome sequencing. While metagenomic sequencing approaches have been used to sequence many of the early mpox infections, these methods are resource intensive and require samples with high viral DNA concentrations. Given the atypical clinical presentation of cases associated with the outbreak and uncertainty regarding viral load across both the course of infection and anatomical body sites, there was an urgent need for a more sensitive and broadly applicable sequencing approach. Highly multiplexed amplicon-based sequencing (PrimalSeq) was initially developed for sequencing of Zika virus, and later adapted as the main sequencing approach for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Here, we used PrimalScheme to develop a primer scheme for human monkeypox virus that can be used with many sequencing and bioinformatics pipelines implemented in public health laboratories during the COVID-19 pandemic. We sequenced clinical specimens that tested presumptively positive for human monkeypox virus with amplicon-based and metagenomic sequencing approaches. We found notably higher genome coverage across the virus genome, with minimal amplicon drop-outs, in using the amplicon-based sequencing approach, particularly in higher PCR cycle threshold (Ct) (lower DNA titer) samples. Further testing demonstrated that Ct value correlated with the number of sequencing reads and influenced the percent genome coverage. To maximize genome coverage when resources are limited, we recommend selecting samples with a PCR Ct below 31 Ct and generating 1 million sequencing reads per sample. To support national and international public health genomic surveillance efforts, we sent out primer pool aliquots to 10 laboratories across the United States, United Kingdom, Brazil, and Portugal. These public health laboratories successfully implemented the human monkeypox virus primer scheme in various amplicon sequencing workflows and with different sample types across a range of Ct values. Thus, we show that amplicon-based sequencing can provide a rapidly deployable, cost-effective, and flexible approach to pathogen whole-genome sequencing in response to newly emerging pathogens. Importantly, through the implementation of our primer scheme into existing SARS-CoV-2 workflows and across a range of sample types and sequencing platforms, we further demonstrate the potential of this approach for rapid outbreak response.This publication was made possible by CTSA Grant Number UL1 TR001863 from the National Center for Advancing Translational Science (NCATS), a component of the National Institutes of Health (NIH) awarded to CBFV. INSA was partially funded by the HERA project (Grant/ 2021/PHF/23776) supported by the European Commission through the European Centre for Disease Control (to VB).info:eu-repo/semantics/publishedVersio

Anthrax-like cutaneous lesion on left check of 70-year-old male Florida resident.

<p>Anthrax-like cutaneous lesion on left check of 70-year-old male Florida resident.</p

Results of serological testing of specimens from 2013 Florida patient with anthrax-like cutaneous lesion.

<p>Results of serological testing of specimens from 2013 Florida patient with anthrax-like cutaneous lesion.</p

The missing wit(h)ness: Monroe, fascinance and the unguarded intimacy of being dead

In 1985 journalist Anthony Summers published a post-mortem photograph of Marilyn Monroe, titling it ‘Marilyn in death’, in his book, Goddess: The Secret Lives of Marilyn Monroe (1985), which investigated the theory that her death was not suicide. The photograph thus acquired forensic significance. My questions are these: Is there an inevitable transgression and even violence in the exposure of an image of a dead woman such as we find in Summers’ and other publications? Under the rubric of this collection, unguarded intimacy, I address a set of paintings made from the morgue photograph of a derelict Marilyn Monroe in the era of feminist ethics by two painters, Margaret Harrison (b.1940) and Marlene Dumas (b. 1953). What are the material and theoretical possibilities of creating feminist e(a)ffects in re-workings of this stolen image if we can distinguish between the forensic notion of the silent witness (the pathologist performing an autopsy whose aftermath this photograph in the morgue indexes) and a concept derived from the Matrixial aesthetics of artist-theorist Bracha Ettinger – aesthetic wit(h)nessing? Can such aesthetic wit(h)nessing deflect the unguarded intimacy of seeing an unattended body in its absolute helplessness by inciting compassion

<i>B</i>. <i>cereus</i> BcFL2013 capsule. India ink stain of <i>B</i>. <i>cereus</i> BcFL2013 after overnight growth in defibrinated horse blood.

<p><i>B</i>. <i>cereus</i> BcFL2013 capsule. India ink stain of <i>B</i>. <i>cereus</i> BcFL2013 after overnight growth in defibrinated horse blood.</p

Summary of results for testing of <i>B</i>. <i>cereus</i> BcFL2013 compared to <i>B</i>. <i>cereus</i> G9241 and <i>B</i>. <i>anthracis</i> Ames.

<p>Summary of results for testing of <i>B</i>. <i>cereus</i> BcFL2013 compared to <i>B</i>. <i>cereus</i> G9241 and <i>B</i>. <i>anthracis</i> Ames.</p