To describe CT findings in patients with confirmed Covid-19 infection and correlate them with the disease evolution stages.
This is a historical cohort observational analytical study carried out with ...outpatients, inpatients, and emergency patients from a private hospital in Maceió/AL, Brazil. The final sample consisted of 390 patients with positive RT-PCR for Covid-19 with available laboratory tests and chest CT results.
The most frequent initial symptoms were cough, fever, dyspnea and headache. The most commonly found comorbidities were hypertension, diabetes mellitus and obesity. A total of 22% of the CT scans showed no alterations; ground-glass opacity was the most frequently found one. There was a significant association between age, comorbidities, pulmonary involvement, ground-glass opacity, mosaic attenuation and percentage of pulmonary involvement with death. The analysis of the disease stages showed a significant association with laboratory data (CRP and platelet levels), ground-glass opacity and mosaic attenuation with the disease evolution stages in relation to the days since symptom onset.
The disease evolution of Covid-19 occurs in stages, and this study describes tomographic findings in patients with confirmed Covid-19 infection and shows they vary depending on the disease evolution stages.
This paper provides important addition to the various records that have been accumulated through the Covid-19 pandemic.
Abstract
On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star–black hole merger (NSBH), the first ever identified. An extensive search for an optical ...counterpart of this event, designated GW190814, was undertaken using the Dark Energy Camera on the 4 m Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory. Target of Opportunity interrupts were issued on eight separate nights to observe 11 candidates using the 4.1 m Southern Astrophysical Research (SOAR) telescope’s Goodman High Throughput Spectrograph in order to assess whether any of these transients was likely to be an optical counterpart of the possible NSBH merger. Here, we describe the process of observing with SOAR, the analysis of our spectra, our spectroscopic typing methodology, and our resultant conclusion that none of the candidates corresponded to the gravitational wave merger event but were all instead other transients. Finally, we describe the lessons learned from this effort. Application of these lessons will be critical for a successful community spectroscopic follow-up program for LVC observing run 4 (O4) and beyond.
Summary
The present work describes the isolation and purification of two Leishmania chagasi (= syn. Leishmania infantum) recombinant proteins, rLci2B and rLci1A, and their use in the development of ...an immunoassay for the diagnostic of canine leishmaniasis. After protein expression and cell disruption, rLci2B was purified by immobilized metal affinity chromatography followed by size exclusion chromatography, whereas rLci1A, expressed as an inclusion body, was treated with urea and purified by anion‐exchange chromatography. Homogeneities were ascertained by denaturing gel electrophoresis (MW rLci2B = 46 370; MWrLci1A = 88 400), isoelectric focusing (pI rLci2B = 5·91; pI rLci1A = 6·01) and Western blot. An indirect ELISA was developed using the purified antigens rLci2B and rLci1A and a leishmaniasis canine serum panel (n = 256). The ELISA showed 100% sensitivity and 95% specificity for rLci2B and 96% sensitivity and 92% specificity for rLci1A. The purified proteins did not present cross‐reactivity with sera from dogs infected with Trypanosoma caninum, Babesia canis and Ehrlichia canis. Cross‐reaction was verified with sera from dogs infected with Leishmania brasiliensis (11·7% for rLci2B and 2·9% for rLci1A). Based on ELISA results, it is suggested the use of rLci2B and rLci1A as antigens in an alternative serological assay for diagnostic of canine leishmania.
Context.
The importance of photometric galaxy redshift estimation is rapidly increasing with the development of specialised powerful observational facilities.
Aims.
We develop a new photometric ...redshift estimation workflow TOPz to provide reliable and efficient redshift estimations for the upcoming large-scale survey J-PAS which will observe 8500 deg
2
of the northern sky through 54 narrow-band filters.
Methods.
TOPz relies on template-based photo-
z
estimation with some added J-PAS specific features and possibilities. We present TOPz performance on data from the miniJPAS survey, a precursor to the J-PAS survey with an identical filter system. First, we generated spectral templates based on the miniJPAS sources using the synthetic galaxy spectrum generation software CIGALE. Then we applied corrections to the input photometry by minimising systematic offsets from the template flux in each filter. To assess the accuracy of the redshift estimation, we used spectroscopic redshifts from the DEEP2, DEEP3, and SDSS surveys, available for 1989 miniJPAS galaxies with
r <
22 mag
AB
. We also tested how the choice and number of input templates, photo-
z
priors, and photometric corrections affect the TOPz redshift accuracy.
Results.
The general performance of the combination of miniJPAS data and the TOPz workflow fulfills the expectations for J-PAS redshift accuracy. Similarly to previous estimates, we find that 38.6% of galaxies with
r
< 22 mag reach the J-PAS redshift accuracy goal of d
z
/(1 +
z
) < 0.003. Limiting the number of spectra in the template set improves the redshift accuracy up to 5%, especially for fainter, noise-dominated sources. Further improvements will be possible once the actual J-PAS data become available.
ABSTRACT We report the observation and confirmation of the first group- and cluster-scale strong gravitational lensing systems found in Dark Energy Survey data. Through visual inspection of data from ...the Science Verification season, we identified 53 candidate systems. We then obtained spectroscopic follow-up of 21 candidates using the Gemini Multi-object Spectrograph at the Gemini South telescope and the Inamori-Magellan Areal Camera and Spectrograph at the Magellan/Baade telescope. With this follow-up, we confirmed six candidates as gravitational lenses: three of the systems are newly discovered, and the remaining three were previously known. Of the 21 observed candidates, the remaining 15 either were not detected in spectroscopic observations, were observed and did not exhibit continuum emission (or spectral features), or were ruled out as lensing systems. The confirmed sample consists of one group-scale and five galaxy-cluster-scale lenses. The lensed sources range in redshift z ∼ 0.80-3.2 and in i-band surface brightness iSB ∼ 23-25 mag arcsec−2 (2″ aperture). For each of the six systems, we estimate the Einstein radius θE and the enclosed mass Menc, which have ranges θE ∼ 5″-9″ and Menc ∼ 8 × 1012 to 6 × 1013 M , respectively.
ABSTRACT The Fornax galaxy cluster is the richest nearby (D ∼ 20 Mpc) galaxy association in the southern sky. As such, it provides a wealth of opportunities to elucidate on the processes where ...environment holds a key role in transforming galaxies. Although it has been the focus of many studies, Fornax has never been explored with contiguous homogeneous wide-field imaging in 12 photometric narrow and broad bands like those provided by the Southern Photometric Local Universe Survey (S-PLUS). In this paper, we present the S-PLUS Fornax Project (S+FP) that aims to comprehensively analyse the galaxy content of the Fornax cluster using S-PLUS. Our data set consists of 106 S-PLUS wide-field frames (FoV∼1.4 × 1.4 deg2) observed in five Sloan Digital Sky Survey-like ugriz broad bands and seven narrow bands covering specific spectroscopic features like O ii, Ca ii H+K, Hδ, G band, Mg b triplet, Hα, and the Ca ii triplet. Based on S-PLUS specific automated photometry, aimed at correctly detecting Fornax galaxies and globular clusters in S-PLUS images, our data set provides the community with catalogues containing homogeneous 12-band photometry for ∼3 × 106 resolved and unresolved objects within a region extending over ∼208 deg2 (∼5 Rvir in RA) around Fornax’ central galaxy, NGC 1399. We further explore the eagle and IllustrisTNG cosmological simulations to identify 45 Fornax-like clusters and generate mock images on all 12 S-PLUS bands of these structures down to galaxies with M⋆ ≥ 108 M⊙. The S+FP data set we put forward in this first paper of a series will enable a variety of studies some of which are briefly presented.
Background
Present theory is that uncomplicated and complicated appendicitis are different entities. Recent studies suggest it is safe to delay surgery in patients with uncomplicated appendicitis. We ...hypothesize that patients with complicated appendicitis are at higher risk for postoperative complications when surgery is delayed.
Methods
Data was used from the multicenter, prospective SNAPSHOT appendicitis study of 1975 patients undergoing surgery for suspected appendicitis. Adult patients (≥ 18 years) who underwent appendectomy for appendicitis were included in this study. The primary outcome was the difference in
postoperative complications
between patients with complicated appendicitis who were operated within and after 8 h after hospital presentation. Secondary outcomes were the incidence of both uncomplicated and complicated appendicitis in relationship to delay of appendectomy. Follow-up was 30 days. A multivariable analysis was performed.
Results
Of 1341 adult patients with appendicitis, 34.3% had complicated appendicitis. In patients with complicated appendicitis, 22.8% developed a postoperative complication compared to 8.2% for uncomplicated appendicitis (
P
< 0.001). Delay in surgery (> 8 h) increased the complication rate in patients with complicated appendicitis (28.1%) compared to surgery within 8 h (18.3%;
P
= 0.01). Multivariate analysis showed a delay in surgery as an independent predictor for a postoperative complication in patients with complicated appendicitis (OR 1.71; 95%CI 1.01–2.68,
P
= 0.02).
Conclusion
In-hospital delay of surgery (> 8 h) in patients with complicated appendicitis is associated with a higher risk of a postoperative complication. It is important that we recognize and treat these patients early.
We report the discovery of six ultra-faint Milky Way satellites identified through matched-filter searches conducted using Dark Energy Camera (DECam) data processed as part of the second data release ...of the DECam Local Volume Exploration (DELVE) survey. Leveraging deep Gemini/GMOS-N imaging (for four candidates) as well as follow-up DECam imaging (for two candidates), we characterize the morphologies and stellar populations of these systems. We find that these candidates all share faint absolute magnitudes (MV ≥ -3.2 mag) and old, metal-poor stellar populations (τ > 10 Gyr, Fe/H < -1.4 dex). Three of these systems are more extended (r1/2 > 15 pc), while the other three are compact r1/2 < 10 pc). From these properties, we infer that the former three systems (Boötes V, Leo Minor I, and Virgo II) are consistent with ultra-faint dwarf galaxy classifications, whereas the latter three (DELVE 3, DELVE 4, and DELVE 5) are likely ultra-faint star clusters. Using data from the Gaia satellite, we confidently measure the proper motion of Boötes V, Leo Minor I, and DELVE 4, and tentatively detect a proper-motion signal from DELVE 3 and DELVE 5; no signal is detected for Virgo II. We use these measurements to explore possible associations between the newly discovered systems and the Sagittarius dwarf spheroidal, the Magellanic Clouds, and the Vast Polar Structure, finding several plausible associations. Our results offer a preview of the numerous ultra-faint stellar systems that will soon be discovered by the Vera C. Rubin Observatory and highlight the challenges of classifying the faintest stellar systems.
Searches for counterparts to multimessenger events with optical imagers use difference imaging to detect new transient sources. However, even with existing artifact-detection algorithms, this process ...simultaneously returns several classes of false positives: false detections from poor-quality image subtractions, false detections from low signal-to-noise images, and detections of preexisting variable sources. Currently, human visual inspection to remove the false positives is a central part of multimessenger follow-up observations, but when next generation gravitational wave and neutrino detectors come online and increase the rate of multimessenger events, the visual inspection process will be prohibitively expensive. We approach this problem with two convolutional neural networks operating on the difference imaging outputs. The first network focuses on removing false detections and demonstrates an accuracy of 92% on our data set. The second network focuses on sorting all real detections by the probability of being a transient source within a host galaxy and distinguishes between various classes of images that previously required additional human inspection. We find the number of images requiring human inspection will decrease by a factor of 1.5 using our approach alone and a factor of 3.6 using our approach in combination with existing algorithms, facilitating rapid multimessenger counterpart identification by the astronomical community.
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