Is the Compact Source at the Center of Cas A Pulsed?

A 50 ksec observation of the Supernova Remnant Cas A was taken using the Chandra X-Ray Observatory High Resolution Camera (HRC) to search for periodic signals from the compact source located near the center. Using the HRC-S in imaging mode, problems with correctly assigning times to events were overcome, allowing the period search to be extended to higher frequencies than possible with previous observations. In an extensive analysis of the HRC data, several possible candidate signals are found using various algorithms, including advanced techniques developed by Ransom to search for low significance periodic signals. Of the candidate periods, none is at a high enough confidence level to be particularly favored over the rest. When combined with other information, however (e.g., spectra, total energetics, and the historical age of the remnant), a 12 ms candidate period seems to be more physically plausible than the others, and we use it for illustrative purposes in discussing the possible properties of a putative neutron star in the remnant. We emphasize that this is not necessarily the true period, and that a follow-up observation, scheduled for the fall of 2001, is required. A 50 ksec Advanced CCD Imaging Spectrometer (ACIS) observation was taken, and analysis of these data for the central object shows that the spectrum is consistent with several forms, and that the emitted X-ray luminosity in the 0.1 -10 keV band is 10^{33}-10^{35}erg cm^{-2}sec^{-1} depending on the spectral model and the interstellar absorption along the line of sight to the source.Comment: 14 pages, 3 figures Submitted to ApJ 2001 June 2

The effect of illustrations on patient comprehension of medication instruction labels

BACKGROUND: Labels with special instructions regarding how a prescription medication should be taken or its possible side effects are often applied to pill bottles. The goal of this study was to determine whether the addition of illustrations to these labels affects patient comprehension. METHODS: Study participants (N = 130) were enrolled by approaching patients at three family practice clinics in Toronto, Canada. Participants were asked to interpret two sets of medication instruction labels, the first with text only and the second with the same text accompanied by illustrations. Two investigators coded participants' responses as incorrect, partially correct, or completely correct. Health literacy levels of participants were measured using a validated instrument, the REALM test. RESULTS: All participants gave a completely correct interpretation for three out of five instruction labels, regardless of whether illustrations were present or not. For the two most complex labels, only 34–55% of interpretations of the text-only version were completely correct. The addition of illustrations was associated with improved performance in 5–7% of subjects and worsened performance in 7–9% of subjects. CONCLUSION: The commonly-used illustrations on the medication labels used in this study were of little or no use in improving patients' comprehension of the accompanying written instructions

Differences in Drowning Rates between Rural and Non-Rural Residents of Ontario, Canada

The objective of our study was to determine if rural residence was associated with an increased risk of drowning in Ontario, Canada. We conducted a retrospective cohort study of all unintentional drowning deaths in Ontario Canada from 2004 to 2008. Age-adjusted mortality rates for males and females living in rural and non-rural areas were calculated using direct standardization, with non-rural residents as the reference population. We identified a total of 564 unintentional drowning deaths. The majority (89%) of fatal drowning victims were male, and 75% percent of victims were from non-rural area. Excluding bathtub drowning deaths, the age-adjusted drowning mortality rate was significantly higher for both males (rate ratio 2.8; 95% CI, 2.3- 3.4) and females (rate ratio 2.8; 95% CI 1.5- 5.0) from rural compared to non-rural areas. In Ontario, rural residence was associated with an increased risk of unintentional drowning

Uptake of COVID-19 vaccination among community-dwelling individuals receiving healthcare for substance use disorder and major mental illness: a matched retrospective cohort study

IntroductionPatients with major mental illness (MMI) and substance use disorders (SUD) face barriers in accessing healthcare. In this population-based retrospective cohort study, we investigated the uptake of COVID-19 vaccination in Ontario, Canada among community-dwelling individuals receiving healthcare for major mental illness (MMI) and/or substance use disorders (SUD), comparing them to matched general population controls.MethodsUsing linked health administrative data, we identified 337,290 individuals receiving healthcare for MMI and/or SUD as of 14 December 2020, matched by age, sex, and residential geography to controls without such healthcare. Follow-up extended until 31 December 2022 to document vaccination events.ResultsOverall, individuals receiving healthcare for MMI and/or SUD (N = 337,290) had a slightly lower uptake of first (cumulative incidence 82.45% vs. 86.44%; hazard ratio [HR] 0.83 [95% CI 0.82–0.83]) and second dose (78.82% vs. 84.93%; HR 0.77 [95% CI 0.77–0.78]) compared to matched controls. Individuals receiving healthcare for MMI only (n = 146,399) had a similar uptake of first (87.96% vs. 87.59%; HR 0.97 [95% CI 0.96–0.98]) and second dose (86.09% vs. 86.05%, HR 0.94 [95% CI 0.93–0.95]). By contrast, individuals receiving healthcare for SUD only (n = 156,785) or MMI and SUD (n = 34,106) had significantly lower uptake of the first (SUD 78.14% vs. 85.74%; HR 0.73 [95% CI 0.72–0.73]; MMI & SUD 78.43% vs. 84.74%; HR 0.76 [95% CI 0.75–0.77]) and second doses (SUD 73.12% vs. 84.17%; HR 0.66 [95% CI 0.65–0.66]; MMI & SUD 73.48% vs. 82.93%; HR 0.68 [95% CI 0.67–0.69]).DiscussionThese findings suggest that effective strategies to increase vaccination uptake for future COVID-19 and other emerging infectious diseases among community-dwelling people with SUD are needed

Examining the prevalence of chronic homelessness among single adults according to national definitions in Canada

This article examines the prevalence of chronic homelessness when applying definitions used in Canada to a sample of homeless and vulnerably housed single adults enrolled in a multi-city longitudinal study. The federal government’s current definition, Reaching Home, identified the highest proportion of homeless single adults (31 percent; 95% CI = 27.2 – 34.1) as “chronically homeless.” Our findings suggest that the federal definitions of chronic homelessness, which are based on both shelter stays and periods of homelessness outside the shelter system, are double the size of this sub-population when compared to definitions based on shelter stays alone. Participants who were male, identified as Indigenous, and reported problematic drug use, were more likely to be chronically homeless for definitions based on any-kind of homelessness. The findings highlight the importance of counting unsheltered and hidden homelessness to estimate the number of single adults who are chronically homeless.Cet article examine la prévalence de l’itinérance chronique lors de l’application de définitions utilisées au Canada à un échantillon d’adultes célibataires sans abri et logés de façon vulnérable, inscrits dans une étude longitudinale multi-villes. La définition actuelle du gouvernement fédéral, Reaching Home, a identifié la plus grande proportion d’adultes célibataires sans abri (31 pour cent ; 95 % CI = 27,2 - 34,1) comme «sans abri chronique». Nos résultats suggèrent que les définitions de l’itinérance chronique, qui sont basées à la fois sur les séjours en refuge et les périodes d’itinérance en dehors du système de refuge, représentent le double de la taille de cette sous-population par rapport aux définitions basées uniquement sur les séjours en refuge. Les participants qui étaient de sexe masculin, s’identifiaient comme indigènes et déclaraient avoir fait un usage problématique de drogues, étaient plus susceptibles d’être associés à l’itinérance chronique pour les définitions basées sur tout type d’itinérance. Les résultats soulignent l’importance de compter l’itinérance non abritée et cachée pour estimer le nombre d’adultes célibataires qui sont chroniquement sans abri

Mortality among residents of shelters, rooming houses, and hotels in Canada: 11 year follow-up study

Objective To examine mortality in a representative nationwide sample of homeless and marginally housed people living in shelters, rooming houses, and hotels