With displacement, time, and force as basic undefined physical quantities, other physical quantities are defined as combinations of two vector quantities and one scalar quantity. Combinations include multiplication and division of vectors by vectors, scalars by vectors, and scalars by scalars. Defined quantities are vectors, scalars or quaternions, depending on directions of vectors in the definitions. Division of a vector by a vector is equivalent to multiplication of vectors divided by a scalar. The unit of a vector (or scalar) is (...) itself a vector (or scalar) quantity. Thesquare meter (a vector) differs from meter 2 (a scalar), and the cubic meter (a scalar) is different frommeter 3 . The characteristics of displacement, time, and force are considered known from experience. (shrink)

Quaternions consist of a scalar plus a vector and result from multiplication or division of vectors by vectors. Division of vectors is equivalent to multiplication divided by a scalar. Quaternions as used here consist of the scalar product with positive sign plus the vector product with sign determined by the right-hand rule. Units are specified by the multiplication process. Trigonometric functions are quaternions with units that can satisfy Hamilton's requirements. The square of a trigonometric quaternion is a real number provided (...) that the product of the scalar number and the vector is not commutative. Maxwell's electromagnetic equations for empty space can be represented by a single quaternion equation. (shrink)

Background Regionalised models of health care delivery have important implications for people with disabilities and chronic illnesses yet the ethical issues surrounding disability and regionalisation have not yet been explored. Although there is ethics-related research into disability and chronic illness, studies of regionalisation experiences, and research directed at improving health systems for these patient populations, to our knowledge these streams of research have not been brought together. Using the Canadian province of Ontario as a case study, we address this gap (...) by examining the ethics of regionalisation and the implications for people with disabilities and chronic illnesses. The critical success factors we provide have broad applicability for guiding and/or evaluating new and existing regionalised health care strategies. Discussion Ontario is in the process of implementing fourteen Local Health Integration Networks (LHINs). The implementation of the LHINs provides a rare opportunity to address systematically the unmet diverse care needs of people with disabilities and chronic illnesses. The core of this paper provides a series of composite case vignettes illustrating integration opportunities relevant to these populations, namely: (i) rehabilitation and services for people with disabilities; (ii) chronic illness and cancer care; (iii) senior's health; (iv) community support services; (v) children's health; (vi) health promotion; and (vii) mental health and addiction services. For each vignette, we interpret the governing principles developed by the LHINs – equitable access based on patient need, preserving patient choice, responsiveness to local population health needs, shared accountability and patient-centred care – and describe how they apply. We then offer critical success factors to guide the LHINs in upholding these principles in response to the needs of people with disabilities and chronic illnesses. Summary This paper aims to bridge an important gap in the literature by examining the ethics of a new regionalisation strategy with a focus on the implications for people with disabilities and chronic illnesses across multiple sites of care. While Ontario is used as a case study to contextualize our discussion, the issues we identify, the ethical principles we apply, and the critical success factors we provide have broader applicability for guiding and evaluating the development of – or revisions to – a regionalised health care strategy. (shrink)

A collection of personal narratives and essays, Living Professionalism is designed to help medical students and residents understand and internalize various aspects of professionalism. These essays are meant for personal reflection and above all, for thoughtful discussion with mentors, with peers, with others throughout the health care provider community who care about acting professionally.

BackgroundArtificial intelligence has been described as the “fourth industrial revolution” with transformative and global implications, including in healthcare, public health, and global health. AI approaches hold promise for improving health systems worldwide, as well as individual and population health outcomes. While AI may have potential for advancing health equity within and between countries, we must consider the ethical implications of its deployment in order to mitigate its potential harms, particularly for the most vulnerable. This scoping review addresses the following question: (...) What ethical issues have been identified in relation to AI in the field of health, including from a global health perspective?MethodsEight electronic databases were searched for peer reviewed and grey literature published before April 2018 using the concepts of health, ethics, and AI, and their related terms. Records were independently screened by two reviewers and were included if they reported on AI in relation to health and ethics and were written in the English language. Data was charted on a piloted data charting form, and a descriptive and thematic analysis was performed.ResultsUpon reviewing 12,722 articles, 103 met the predetermined inclusion criteria. The literature was primarily focused on the ethics of AI in health care, particularly on carer robots, diagnostics, and precision medicine, but was largely silent on ethics of AI in public and population health. The literature highlighted a number of common ethical concerns related to privacy, trust, accountability and responsibility, and bias. Largely missing from the literature was the ethics of AI in global health, particularly in the context of low- and middle-income countries.ConclusionsThe ethical issues surrounding AI in the field of health are both vast and complex. While AI holds the potential to improve health and health systems, our analysis suggests that its introduction should be approached with cautious optimism. The dearth of literature on the ethics of AI within LMICs, as well as in public health, also points to a critical need for further research into the ethical implications of AI within both global and public health, to ensure that its development and implementation is ethical for everyone, everywhere. (shrink)

This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)

Both the psychology of perception and the philosophy of perception seem to show a new face when the process is considered at its own level, distinct from that of sensation. Unfamiliar conceptions in physics, anatomy, physiology, psychology, and phenomenology are required to clarify the separation and make it plausible. But there have been so many dead ends in the effort to solve the theoretical problems of perception that radical proposals may now be acceptable. Scientists are often more conservative than philosophers (...) of science. I end, therefore, as I began, with a plea for help. (shrink)

For centuries psychologists have been trying to explain how a man or an animal could perceive space. They have thought of space as having three dimensions and the difficulty was how an observer could see the third dimension. For depth, as Bishop Berkeley asserted at the outset of the New Theory of Vision (1709), “is a line endwise to the eye which projects only one point in the fund of the eye.” Space was its dimensions. It was empty save for (...) a collection of objects or bodies. For an observer, the objects were in different directions at various distances and the question was how these distances could be detected. For two hundred and fifty years we have tried to answer this question and failed. The explanations have been controversial, contradictory, and confused. (shrink)

We have synthesized a 582,970-base pair Mycoplasma genitalium genome. This synthetic genome, named M. genitalium JCVI-1.0, contains all the genes of wild-type M. genitalium G37 except MG408, which was disrupted by an antibiotic marker to block pathogenicity and to allow for selection. To identify the genome as synthetic, we inserted "watermarks" at intergenic sites known to tolerate transposon insertions. Overlapping "cassettes" of 5 to 7 kilobases (kb), assembled from chemically synthesized oligonucleotides, were joined by in vitro recombination to produce intermediate (...) assemblies of approximately 24 kb, 72 kb ("1/8 genome"), and 144 kb ("1/4 genome"), which were all cloned as bacterial artificial chromosomes in Escherichia coli. Most of these intermediate clones were sequenced, and clones of all four 1/4 genomes with the correct sequence were identified. The complete synthetic genome was assembled by transformation-associated recombination cloning in the yeast Saccharomyces cerevisiae, then isolated and sequenced. A clone with the correct sequence was identified. The methods described here will be generally useful for constructing large DNA molecules from chemically synthesized pieces and also from combinations of natural and synthetic DNA segments. 10.1126/science.1151721. (shrink)