A Review on Deep Learning Approaches for Spectral Imaging

Deep learning algorithms have revolutionized the computer vision field in the last decade. They can reduce tedious feature engineering and have opened new possibilities of automated visual inspection. With deep learning techniques, the availability of large amounts of qualitative labeled data became more important than ever. The main share of computer vision research focuses on RGB images. With the advances in sensor technologies multi- and hyperspectral cameras have become more cost effective and accessible in recent years, allowing this imaging technology to be applied to new fields of application. This article gives an overview of approaches to apply deep learning techniques to multi- or hyperspectral data. Several state-of-the-art methods will be reviewed and problems and difficulties will be discussed. An overview of a selection of available datasets is presented. To give a broad and diverse insight, research from different fields of application are considered, namely the remote sensing domain, the agricultural domain and the food industry

Legalisation of non-medical cannabis in Canada: will supply regulations effectively serve public health?

Canadian Institutes of Health Research for the Ontario Canadian Research Initiative in Substance Misuse Node Team [SMN-139150]Endowed Chair in Addiction Psychiatry, Department of Psychiatry, University of TorontoCAMH, Inst Mental Hlth Policy Res, Toronto, ON M5S 2S1, CanadaUniv Toronto, Inst Med Sci, Dept Psychiat, Toronto, ON, CanadaUniv Toronto, Ctr Criminol & Sociolegal Studies, Toronto, ON, CanadaSimon Fraser Univ, Ctr Appl Res Mental Hlth & Addict, Fac Hlth Sci, Vancouver, BC, CanadaFed Univ Sao Paulo UNIFESP, Dept Psychiat, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Dept Psychiat, Sao Paulo, BrazilWeb of Scienc

The bias of avoiding spatial dynamic panel models: A tale of two research teams

Many questions in urban and regional economics can be characterized as including both a spatial and a time dimension. However, often one of these dimensions is neglected in empirical work. This paper highlights the danger of methodological inertia, investigating the effect of neglecting the spatial or the time dimension when in fact both are important. A tale of two research teams, one living in a purely dynamic and the other in a purely spatial world of thinking, sets the scene. Because the researcher teams' choices to omit a dimension change the assumed optimal estimation strategies, the issue is more difficult to analyze than a typical omitted variables problem. First, the bias of omitting a relevant dimension is approximated analytically. Second, Monte Carlo simulations show that the neglected dimension projects onto the other, with potentially disastrous results. Interestingly, dynamic models are bound to overestimate autoregressive behavior whenever the spatial dimension is important. The same holds true for the opposite case. An application using the well-known, openly available cigarette demand data supports these findings

A qualitative exploration of prescription opioid injection among street-based drug users in Toronto: behaviours, preferences and drug availability

<p>Abstract</p> <p>Background</p> <p>There is evidence of a high prevalence of prescription opioid (PO) and crack use among street drug users in Toronto. The purpose of this qualitative study was to describe drug use behaviours and preferences as well as the social and environmental context surrounding the use of these drugs among young and old street-based drug injection drug users (IDUs).</p> <p>Methods</p> <p>In-depth interviews were conducted with 25 PO injectors. Topics covered included drug use history, types of drugs used, how drugs were purchased and transitions to PO use. Interviews were taped and transcribed. Content analysis was conducted to identify themes.</p> <p>Results</p> <p>Five prominent themes emerged from the interviews: 1) Combination of crack and prescription opioids, 2) First injection experience and transition to prescription opioids, 3) Drug preferences and availability, 4) Housing and income and 5) Obtaining drugs. There was consensus that OxyContin and crack were the most commonly available drugs on the streets of Toronto. Drug use preferences and behaviours were influenced by the availability of drugs, the desired effect, ease of administration and expectations around the purity of the drugs. Distinct experiences were observed among younger users as compared to older users. In particular, the initiation of injection drug use and experimentation with POs among younger users was influenced by their experiences on the street, their peers and general curiosity.</p> <p>Conclusion</p> <p>Given the current profile of street-based drug market in Toronto and the emergence of crack and POs as two predominant illicit drug groups, understanding drug use patterns and socio-economic factors among younger and older users in this population has important implications for preventive and therapeutic interventions. </p

The Use of Fuzzy Set Theory in Remote Sensing Pattern Recognition

Satellite images increasingly become a major data source for monitoring changes in the natural environment. A main task in the analysis of satellite images is concerned with the modelling of land use classes by reducing uncertainty during a classification process. In the approach presented in this paper uncertainty is perceived to be due to the vagueness of geographical categories caused by either the complexity of the category (like 'urban area') or by the use of the category in several application contexts. Two circumstances of use of an extended set theoretical concept (fuzzy sets) are discussed. First, two algorithms from the ISODATA class are used to determine the grades of membership to three a priori defined classes (woodland, suburban area, urban area) of a LANDSAT TM satellite image of Vienna, Austria. The results are visualized by a RGB image of the grades of membership to each category. Second, a measure of fuzziness is employed on the results. The measure relies on the concept of distance between a seUcategory and its complement. The so determined vagueness provide more information on the uncertainty of the different categories and may improve further information processing tasks. (authors' abstract)Series: Discussion Papers of the Institute for Economic Geography and GIScienc

Trends and Changes in Prescription Opioid Analgesic Dispensing In Canada 2005-2012: An Update with a Focus on Recent Interventions

Background Prescription opioid analgesic (POA) utilization has steeply increased globally, yet is far higher in established market economies than elsewhere. Canada features the world’s second-highest POA consumption rates. Following increases in POA-related harm, several POA control interventions have been implemented since 2010. Methods We examined trends and patterns in POA dispensing in Canada by province for 2005–2012, including a focus on the potential effects of interventions. Data on annual dispensing of individual POA formulations – categorized into ‘weak opioids’ and ‘strong opioids’ – from a representative sub-sample of 5,700 retail pharmacies across Canada (from IMS Brogan’s Compuscript) were converted into Defined Daily Doses (DDD), and examined intra- and inter-provincially as well as for Canada (total). Results Total POA dispensing – driven by strong opioids – increased across Canada until 2011; four provinces indicated decreases in strong opioid dispensing; seven provinces indicated decreases specifically in oxycodone dispensing, 2011–2012. The dispensing ratio weak/strong opioids decreased substantively. Major inter-provincial differences in POA dispensing levels and qualitative patterns of POA formulations dispensed persisted. Previous increasing trends in POA dispensing were reversed in select provinces 2011–2012, coinciding with POA-related interventions. Conclusions Further examinations regarding the sustained nature, drivers and consequences of the recent trend changes in POA dispensing – including possible ‘substitution effects’ for oxycodone reductions – are needed

The Opioid Mortality Epidemic in North America: Do We Understand the Supply Side Dynamics of This Unprecedented Crisis?

While there has been extensive attention to the ‘demand side’ – or use and adverse consequences, including mortality – of the ‘opioid crisis’ presently unfolding across North America, few considerations have focused on the supply side. This paper examines the supply side dynamics of this unprecedented public health phenomenon. We provide evidence for several interrelated supply-side elements that have contributed to the present public health crisis. We observe that initially, persistently high levels of prescription opioid availability and use exposed large proportions of the North American population to opioids, resulting in correspondingly high levels of medical and non-medical use (e.g., involving diversion). While various intervention measures to control prescription opioid availability and use have been implemented in recent years, leading to eventual reductions in opioid dispensing levels, these occurred late in the crisis’s evolution. Moreover, these supply reductions have not been met by corresponding reductions in opioid use or demand levels. These growing discrepancies between opioid demand and prescription-based sources have left major gaps in opioid supplies. In response to such supply gaps, highly potent and toxic illicit opioid products have rapidly proliferated across North America, and become a core driver of the dramatic spikes in opioid overdose fatality levels in recent years. These supply-related interrelations are corroborated by a corresponding increase in illicit opioid-related fatalities, which arose just as medical opioid supplies began to decrease in many jurisdictions. Improved analyses and understanding of the supply-side dynamics of the opioid crisis are urgently needed in order to inform future intervention and policy development. Meanwhile, the high mortality toll related to illicit, highly toxic opioid exposure requires sustained solutions, including supply-oriented measures (e.g., safer opioid distribution for at–risk users) towards improved public health protection

Austrian Outbound Foreign Direct Investment in Europe: A spatial econometric study

This paper focuses on Austrian outbound foreign direct investment (FDI, measured by sales of Austrian affiliates abroad) in Europe over the period 2009-2013, using a spatial Durbin panel data model specification with fixed effects, and a spatial weight matrix based on the first-order contiguity relationship of the countries and normalised by its largest eigenvalue. Third-country effects essentially enter the empirical analysis in two major ways: first, by the endogenous spatial lag on FDI (measured by FDI into markets nearby the host country), and, second, by including an exogenous market potential variable that measures the size of markets nearby the FDI host country in terms of gross domestic product. The question whether the empirical result is compatible with horizontal, vertical, export-platform or complex vertical FDI then depends on the sign and significance levels of both the coefficient of the spatial lag on FDI and the direct impact estimate of the market potential variable. The paper yields robust results that provide significant empirical evidence for horizontal FDI as the main driver of Austrian outbound FDI in Europe. This result is strengthened by the indirect impact estimate of the market potential variable indicating that spatial spillovers do not matter.Series: Working Papers in Regional Scienc

Some Notes on the Use, Concept and Socio-political Framing of ‘stigma’ Focusing on an Opioid-related Public Health Crisis

Canada has been home to a longstanding public health crisis related to opioids, including an extensive mortality and morbidity toll in the face of substantive intervention gaps. Recently (2019), two extensive reports from preeminent federal authorities – the Chief Public Health Officer and the Mental Health Commission of Canada – have been tabled with detailed, core focus on the phenomenon of ‘stigma’ and its impacts on substance/opioid use and harms. The reports present extensive descriptions of the nature and effects, as well as a multitude of prescriptions for remedial measures and actions to “stop the cycle of stigma”. Closer reading of the documents, however, suggests substantial conceptual and empirical limitations in the characterization of the – multi-faceted and challenging – nature and workings of ‘stigma’ as a socio-political, structural or individual process or force, specifically as it applies to and negatively affects substance use and related outcomes, primarily the wellbeing of substance users. Concretely, it is unclear how the remedial actions proposed will materially alleviate stigma process and impacts, especially given apparent gaps in the issues examined, including essential strategies – for example, reform of drug user criminalization as a fundamental element and driver of structural stigma - for action that directly relate to the jurisdictions and privileged mandates of the report sources themselves as health and policy leaders. The commentary provides some concrete while subjective notes and observations on the dynamics of stigma as applies to and framed for substance/opioid use, as well as strategies and measures necessary to both tangibly address the material health and wellbeing of substance users, and related forces of stigma, in the distinct context of the opioid crisis in Canada

Assessing the Prevalence Of Non-Medical Prescription Opioid Use In The Canadian General Adult Population: Evidence Of Large Variation Depending On Survey Questions Used

Background Morbidity and mortality related to Prescription Opioid Analgesics (POAs) have been rising sharply in North America. Non-Medical Prescription Opioid Use (NMPOU) in the general population is a key indicator of POA-related harm, yet the role of question item design for best NMPOU prevalence estimates in general population surveys is unclear, and existing NMPOU survey data for Canada are limited. Methods We tested the impact of different NMPOU question items by comparing an item in the 2008 and 2009 (N&thinsp;=&thinsp;2,017) samples of the CAMH Monitor surveys – an Ontario adult general population survey – with a newly developed item used in the 2010 (N&thinsp;=&thinsp;2,015) samples of the Centre for Addiction and Mental Health (CAMH) Monitor surveys. To control for a potential difference in the population demographics between surveys, we adjusted for gender, age, region, income, prescription opioid use, cigarette smoking, weekly binge drinking, cannabis use in the past three months, and psychological distress in our analyses. Results The prevalence of NMPOU as measured by the 2008 and 2009 CAMH monitor (2.0% [95% CI: 1.2% to 2.8%]) was significantly different when compared to the prevalence of NMPOU as measured by the 2010 CAMH monitor (7.7% [95% CI: 6.3% to 9.2%]) (p&thinsp;&lt;&thinsp;0.001). This difference was also found when stratifying our analysis by sex (p&thinsp;&lt;&thinsp;0.001) and when adjusting for all potential confounding covariates. Conclusion It is highly unlikely that the extensive NMPOU prevalence differences observed from the different survey items reflect an actual increase of NMPOU or changes in NMPOU determinants, but rather point to measurement effects. It appears that we currently do not have accurate estimates of NMPOU in the Canadian general population, even though these estimates are needed to guide and implement targeted interventions. Given the current substantial morbidity and mortality impact of NMPOU, there is an urgent need to systematically develop, validate and standardize NMPOU items for future general population surveys in Canada