Optimal Imaging of Remote Bodies Using Quantum Detectors.

We implement a general imaging method by measuring the complex degree of coherence using linear optics and photon number resolving detectors. In the absence of collective or entanglement-assisted measurements, our method is optimal over a large range of practically relevant values of the complex degree of coherence. We measure the size and position of a small distant source of pseudothermal light, and show that our method outperforms the traditional imaging method by an order of magnitude in precision. Finally, we show that a lack of photon-number resolution in the detectors has only a modest detrimental effect on measurement precision and simulate imaging using the new and traditional methods with an array of detectors, showing that the new method improves both image clarity and contrast.

"Another thing to live for": Supporting HCV treatment and cure among Indigenous people impacted by substance use in Canadian cities.

BACKGROUND: Colonization and colonial systems have led to the overrepresentation of Indigenous people impacted by substance use and HCV infection in Canada. It is critical to ensure Indigenous people's equitable access to new direct acting antiviral HCV treatments (DAAs). Identifying culturally-safe, healing-centered approaches that support the wellbeing of Indigenous people living with HCV is an essential step toward this goal. We listened to the stories and perspectives of HCV-affected Indigenous people and HCV treatment providers with the aim of providing pragmatic recommendations for decolonizing HCV care. METHODS: Forty-five semi-structured interviews were carried out with Indigenous participants affected by HCV from the Cedar Project (n = 20, British Columbia (BC)) and the Canadian Coinfection Cohort (n = 25, BC; Ontario (ON); Saskatchewan (SK)). In addition, 10 HCV treatment providers were interviewed (n = 4 BC, n = 4 ON, n = 2 SK). Interpretive description identified themes to inform clinical approaches and public health HCV care. Themes and related recommendations were validated by Indigenous health experts and Indigenous participants prior to coding and re-contextualization. RESULTS: Taken together, participants' stories and perceptions were interpreted to coalesce into three overarching and interdependent themes representing their recommendations. First: treatment providers must understand and accept colonization as a determinant of health and wellness among HCV-affected Indigenous people, including ongoing cycles of child apprehension and discrimination within the healthcare system. Second: consistently safe attitudes and actions create trust within HCV treatment provider-patient relationships and open opportunities for engagement into care. Third: treatment providers who identify, build, and strengthen circles of care will have greater success engaging HCV-affected Indigenous people who have used drugs into care. CONCLUSION: There are several pragmatic ways to integrate Truth and Reconciliation as well as Indigenous concepts of whole-person wellness into the HCV cascade of care. By doing so, HCV treatment providers have an opportunity to create greater equity and support long-term wellness of Indigenous patients.

The Cedar Project: exploring determinants of psychological distress among young Indigenous people who use drugs in three Canadian cities.

BACKGROUND: Mental health and wellbeing, including addressing impacts of historical trauma and substance use among young people, has been identified as a key priority by Indigenous communities and leaders across Canada and globally. Yet, research to understand mental health among young Indigenous people who have used drugs is limited. AIMS: To examine longitudinal risk and strengths-based factors associated with psychological distress among young Indigenous people who use drugs. METHOD: The Cedar Project is an ongoing cohort study involving young Indigenous people who use drugs in Vancouver, Prince George, and Chase, British Columbia, Canada. This study included participants who completed the Symptom Checklist-90-Revised, returned for follow-up between 2010 and 2012, and completed the Childhood Trauma Questionnaire. Adjusted linear mixed-effects models estimated effects of study variables on changes in area T-scores of psychological distress. RESULTS: Of 202 eligible participants, 53% were women and the mean age was 28 years. Among men, childhood maltreatment (emotional abuse, physical abuse, sexual abuse, physical neglect), any drug use, blackouts from drinking, and sex work were associated with increased distress. Among women, childhood maltreatment (emotional abuse, physical abuse, physical neglect), blackouts from drinking, and sexual assault were associated with increased distress, while having attempted to quit using drugs was associated with reduced distress. Marginal associations were observed between speaking their traditional language and living by traditional culture with lower distress among men. CONCLUSION: Culturally safe mental wellness interventions are urgently needed to address childhood trauma and harmful coping strategies that exacerbate distress among young Indigenous people who use drugs.

Energy cost of treadmill and floor walking at self-selected paces.

Oxygen uptake-velocity regression equations were developed for floor and level treadmill walking by having two groups of men, aged 19-29 years (n = 20) and 55-66 years (n = 22), walk at four self-selected paces, from "rather slowly" to "as fast as possible". A two-variable quadratic model relating VO2 (ml X kg-1 X min-1) to velocity (m X s-1) was adopted for prediction purposes. However, age and fatness significantly (P less than 0.05) interacted with treadmill walking speed, while age alone significantly interacted with floor speed. In addition, a significant difference was found between the energy cost of floor and treadmill walking. For example at the normal walking speed of 1.33 m X s-1, the energy cost for the treadmill (age 55-66 years) was 10.58 ml X kg-1 X min-1 and for the floor, 11.04 ml X kg-1 X min-1 (P less than 0.05). Four quadratic equations are therefore presented, one each for floor and treadmill in each of the two age-groups. The percent variance explained was between 87 and 95% for each of these equations.

Determinants of self-selected walking pace across ages 19 to 66.

To describe the association between self-selected speeds of walking, and age, maximal aerobic power, and body size, 84 men aged 19 to 66 years were asked to walk at four self-selected paces, from rather slowly to as fast as possible. Speed of walking was measured over a 240-m indoor course. Maximal oxygen uptake was determined on a treadmill. The speed of walking was significantly slower in the oldest (55 to 66 years) compared with the youngest group (19 to 29 years) at the normal fast, and as fast as possible speeds. However, when age, weight, height, and fatness were held constant in a multiple regression model, VO2 max was significantly related to speed of walking at the three fastest walking paces. Age was not significantly related to speed of walking at any pace. Thus, this study indicated that the speed of self-selected walking paces was associated with maximal aerobic power independent of age.