QSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring

We present VR observations of QSO 2237+0305 conducted by the GLITP collaboration from 1999 October 1 to 2000 February 3. The observations were made with the 2.56 m Nordic Optical Telescope at Roque de los Muchachos Observatory, La Palma (Spain). The PSF fitting method and an adapted version of the ISIS subtraction method have been used to derive the VR light curves of the four components (A-D) of the quasar. The mean errors range in the intervals 0.01-0.04 mag (PSF fitting) and 0.01-0.02 mag (ISIS subtraction), with the faintest component (D) having the largest uncertainties. We address the relatively good agreement between the A-D light curves derived using different filters, photometric techniques, and telescopes. The new VR light curves of component A extend the time coverage of a high magnification microlensing peak, which was discovered by the OGLE team.Comment: 15 pages, 3 figures, ApJ accepted (Feb 19

Accuracy of routine laboratory tests to predict mortality and deterioration to severe or critical COVID-19 in people with SARS-CoV-2

Objectives This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:  To assess the accuracy of routine blood-based laboratory tests to predict mortality and deterioration to severe or critical (from mild or moderate) COVID-19 in people with SARS-CoV-2 infection. Secondary objectives Where data are available, we will investigate whether prognostic accuracy varies according to a specific measurement or test, reference standard, timing of outcome verification, sample type, study design, and setting, including prevalence of the target condition (either by stratified analysis or meta-regression)

Adiabatic invariants and Mixmaster catastrophes

We present a rigorous analysis of the role and uses of the adiabatic invariant in the Mixmaster dynamical system. We propose a new invariant for the global dynamics which in some respects has an improved behaviour over the commonly used one. We illustrate its behaviour in a number of numerical results. We also present a new formulation of the dynamics via Catastrophe Theory. We find that the change from one era to the next corresponds to a fold catastrophe, during the Kasner shifts the potential is an Implicit Function Form whereas, as the anisotropy dissipates, the Mixmaster potential must become a Morse 0--saddle. We compare and contrast our results to many known works on the Mixmaster problem and indicate how extensions could be achieved. Further exploitation of this formulation may lead to a clearer understanding of the global Mixmaster dynamics.Comment: 24 pages, LaTeX, 5 figures (which can be obtained by sending a message to the first author), submitted to Phys.Rev.

Prevalence of SARS-CoV-2 antibodies among Belgian nursing home residents and staff during the primary COVID-19 vaccination campaign.

peer reviewed[en] BACKGROUND: Nursing home residents (NHR) and staff have been disproportionally affected by the COVID-19 pandemic and were therefore prioritised in the COVID-19 vaccination strategy. However, frail older adults, like NHR, are known to have decreased antibody responses upon vaccination targeting other viral antigens. OBJECTIVES: As real-world data on vaccine responsiveness, we assessed the prevalence of SARS-CoV-2 antibodies among Belgian NHR and staff during the primary COVID-19 vaccination campaign. METHODS: In total, we tested 1629 NHR and 1356 staff across 69 Belgian NHs for the presence of SARS-CoV-2 IgM/IgG antibodies using rapid tests. We collected socio-demographic and COVID-19-related medical data through questionnaires. Sampling occurred between 1 February and 24 March 2021, in a randomly sampled population that received none, one or two BNT162b2 vaccine doses. RESULTS: We found that during the primary vaccination campaign with 59% of the study population fully vaccinated, 74% had SARS-CoV-2 antibodies. Among fully vaccinated individuals only, fewer residents tested positive for SARS-CoV-2 antibodies (77%) than staff (98%), suggesting an impaired vaccine-induced antibody response in the elderly, with lowest seroprevalences observed among infection naïve residents. COVID-19 vaccination status and previous SARS-CoV-2 infection were predictors for SARS-CoV-2 seropositivity. Alternatively, age ≥ 80 years old, the presence of comorbidities and high care dependency predicted SARS-CoV-2 seronegativity in NHR. CONCLUSION: These findings highlight the need for further monitoring of SARS-CoV-2 immunity upon vaccination in the elderly population, as their impaired humoral responses could imply insufficient protection against COVID-19. TRIAL REGISTRATION: This study was retrospectively registered on ClinicalTrials.gov (NCT04738695)

Point-of-care C-reactive protein test results in acute infections in children in primary care:an observational study

BACKGROUND: Acute infections are a common reason for children to consult primary care. Serious infections are rare but differentiating them from self-limiting illnesses remains challenging. This can lead to inappropriate antibiotic prescribing. Point-of-care C-reactive protein testing is used to guide antibiotic prescribing in adults. However, in children its use remains unclear. The purpose of this study was to assess point-of-care CRP test levels with respect to patients' characteristics, care setting, preliminary diagnosis, and management. METHODS: A prospective observational study was performed in children with an acute infection presenting to ambulatory care in Belgium. RESULTS: In this study 8280 cases were analysed, of which 6552 had a point-of-care CRP value available. A total of 276 physicians participated. The median patient age was 1.98 years (IQR 0.97 to 4.17), 37% of children presented to a general practitioner, 33% to a paediatric out-patient clinic, and 30% to the emergency department. A total of 131 different preliminary diagnoses were found, with acute upper airway infection as the most frequent. In 6% (n = 513) patients were diagnosed with a serious infection. The most common serious infection was pneumonia. Antibiotics were prescribed in 28% (n = 2030) of all episodes. The median CRP over all infectious episodes was 10 mg/L (IQR < 5-29). Children below 5 years of age and those presenting to a paediatrician had a higher median CRP. Median CRP in patients with serious infections was 21 mg/L (IQR 6 to 63.5). Pneumonia had a median CRP of 48 mg/L (IQR 13-113). In the episodes with antibiotics prescription, median CRP level was 29 mg/L (IQR 10-58) compared to 7 mg/L (IQR < 5-19) when they were not prescribed. CONCLUSION: A low POC CRP as a standalone tool did not seem to be sufficient to rule out serious infections, but its potential in assessing serious infections could increase when integrated in a clinical decision rule. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02024282 (registered on 31/12/2013)

Close pairs of quasars with different redshifts: New observations and results

Burbidge et al. ([CITE]) argue that the observed number of quasar pairs with small angular separations and different redshifts (typically \Delta \theta \leq 5\,\arcsec and $\Delta z > 0.1$) is not compatible with a random distribution of quasars over the sky. After a brief review of all known quasar pairs with different redshifts, we show by means of very simple calculations that the probability of finding the three accepted pairs accidentally is of the order of 10%. We conclude that, under realistic hypotheses, the observed number of quasar pairs with different redshifts is not unlikely. We also present arguments showing that gravitational lensing biases are probably not strong enough to significantly increase the expected number of quasar pairs. The failure to detect with HST a secondary lensed image of the background quasar near the foreground one in these three pairs supports this view

Vaccine Hesitancy towards the COVID-19 Vaccine in a Random National Sample of Belgian Nursing Home Staff Members

In Belgium, nursing home staff (NHS) and residents were prioritised for COVID-19 vaccination. However, vaccine hesitancy may have impacted vaccination rates. In this study, a random stratified sample of NHS (N = 1142), vaccinated and unvaccinated, completed an online questionnaire on COVID-19 vaccine hesitancy (between 31 July and 15 November 2021). NHS who hesitated or refused the vaccine were asked for the main reason for their hesitation/refusal. Those who hesitated, but eventually accepted vaccination, were asked why they changed their minds. Overall, 29.5% of all respondents hesitated before accepting vaccination, were still hesitating, or refused vaccination. Principal reasons were fear of unknown future effects (55.1% of vaccinated participants that hesitated and 19.5% who refused), fear of side-effects (12.7% of vaccinated participants that hesitated and 12.2% who refused), and mistrust in vaccination (10.5% of vaccinated participants that hesitated and 12.2% who refused). For vaccinated participants who hesitated initially, protecting the vulnerable was the main reason they changed their minds. Given this degree of fear and proposals to mandate vaccination among healthcare workers, communicating with NHS on the safety and efficacy of the vaccine should be prioritised

Prevalence of SARS-CoV-2 antibodies among Belgian nursing home residents and staff during the primary COVID-19 vaccination campaign

BackgroundNursing home residents (NHR) and staff have been disproportionally affected by the COVID-19 pandemic and were therefore prioritised in the COVID-19 vaccination strategy. However, frail older adults, like NHR, are known to have decreased antibody responses upon vaccination targeting other viral antigens.ObjectivesAs real-world data on vaccine responsiveness, we assessed the prevalence of SARS-CoV-2 antibodies among Belgian NHR and staff during the primary COVID-19 vaccination campaign.MethodsIn total, we tested 1629 NHR and 1356 staff across 69 Belgian NHs for the presence of SARS-CoV-2 IgM/IgG antibodies using rapid tests. We collected socio-demographic and COVID-19-related medical data through questionnaires. Sampling occurred between 1 February and 24 March 2021, in a randomly sampled population that received none, one or two BNT162b2 vaccine doses.ResultsWe found that during the primary vaccination campaign with 59% of the study population fully vaccinated, 74% had SARS-CoV-2 antibodies. Among fully vaccinated individuals only, fewer residents tested positive for SARS-CoV-2 antibodies (77%) than staff (98%), suggesting an impaired vaccine-induced antibody response in the elderly, with lowest seroprevalences observed among infection naive residents. COVID-19 vaccination status and previous SARS-CoV-2 infection were predictors for SARS-CoV-2 seropositivity. Alternatively, age >= 80 years old, the presence of comorbidities and high care dependency predicted SARS-CoV-2 seronegativity in NHR.ConclusionThese findings highlight the need for further monitoring of SARS-CoV-2 immunity upon vaccination in the elderly population, as their impaired humoral responses could imply insufficient protection against COVID-19

Declining prevalence of SARS-CoV-2 antibodies among vaccinated nursing home residents and staff six months after the primary BNT162b2 vaccination campaign in Belgium : a prospective cohort study

In the SCOPE study, we monitored SARS-CoV-2 antibodies in a national sample of residents and staff from Belgian nursing homes. Here, we report the seroprevalence among infected and infection-naive residents and staff after the primary COVID-19 vaccination campaign. Among 1554 vaccinated nursing home residents and 1082 vaccinated staff from 69 nursing homes in Belgium, we assessed the proportion having SARS-CoV-2 antibodies approximately two (April 2021), four (June 2021), and six months (August 2021) after a two-dose regimen of the BNT162b2 vaccine. We measured the seroprevalence using SARS-CoV-2 antibody rapid tests and collected socio-demographic and COVID-19 medical data using an online questionnaire. Two months after vaccination (baseline), we found a seroprevalence of 91% (95% CI: 89-93) among vaccinated residents and 99% (95% CI: 98-99) among vaccinated staff. Six months after vaccination, the seroprevalence significantly decreased to 68% (95% CI: 64-72) among residents and to 89% (95% CI; 86-91) among staff (p < 0.001). The seroprevalence was more likely to decrease among infection-naive residents, older residents, or residents with a high care dependency level. These findings emphasize the need for close monitoring of nursing home residents, as a substantial part of this population fails to mount a persistent antibody response after BNT162b2 vaccination