Browse "Science & Technology"

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Article

Optometry

Optometry [Gk optos, "visible" and metron, "measure"] is the profession of examining eyes for faults of refraction, ocular mobility and visual perception and of the treatment of abnormal conditions with correctional lenses and orthoptics.
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Article

Organic Agriculture

Organic agriculture is defined as the sustainable cultivation of land for food production that nourishes soil life, nurtures animals in their natural environment and feeds them according to their physiology.
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Macleans

'Organic' Food Label Questioned

While working as an independent organic food inspector, Mischa Popoff says he felt like "a police officer without a billy club or handcuffs.This article was originally published in Maclean's Magazine on September 10, 2007
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Article

Ornamentals

Ornamentals, in horticulture, include both woody and herbaceous plants used primarily as amenities.
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Macleans

Osteoporosis Breakthrough

In the spring of 1997, William Boyle, a microbiologist at Amgen Inc., a drug company based near Los Angeles, placed a telephone call to Dr. Josef Penninger, an immunologist at the firm's Toronto offshoot, the Amgen Research Institute.This article was originally published in Maclean's Magazine on February 8, 1999
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Macleans

Ottawa takes on reproductive technology

The new federal law on reproductive technology tabled last week was a long time coming. A royal commission studied the subject exhaustively from 1989 to 1993.This article was originally published in Maclean's Magazine on May 20, 2002
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Macleans

Our Dying Seas

This article was originally published in Maclean’s magazine on October 5, 1998. Partner content is not updated.
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Article

Ozone Depletion

Ozone depletion is a chemical thinning of the OZONE LAYER in the stratosphere or upper atmosphere. Scientists determined in the 1970s that it is caused by ozone depleting substances (ODSs), particularly by the use of chlorofluorocarbons (CFCs).
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Article

Pablum

Pablum is a multi-grain processed cereal developed as a nutritious, precooked digestible food for infants. The cereal was first developed at the Hospital for Sick Children in Toronto in 1930 by pediatric doctors Theodore Drake and Frederick Tisdall under the supervision of physician-in-chief Alan Brown. Pablum became commercially available in 1934 through an agreement with the Mead Johnson & Company and was used as a brand name through the early 21st century.
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Article

Paleontology

Paleontology is the study of fossils and gives us knowledge of past life, helps us understand the nature of ancient organisms and provides information about the composition of the biomass of past times. The organisms now living represent a stage in the succession of life forms and, according to the concept of evolution, have descended from past life forms. It is difficult to estimate how many species now exist; the number may be in excess of 45 million. Some authorities estimate that 1.5 million living species (monerans, protistans, fungi, plants and animals) have actually been found and described.
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Article

Palliser Expedition

The explorers amassed astronomical, meteorological, geological and magnetic data, and described the country, its fauna and flora, its inhabitants and its "capabilities" for settlement and transportation.
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Article

Palynology

Palynology is the study of spores and pollen, has many applications in botany, geology and medicine. Spores are primitive reproductive bodies of fungi and some plants. Pollen grains are small male reproductive bodies produced and dispersed by seed plants. Spores and pollen are small (5–100 μm), spherical or oblong structures, identifiable under a compound light microscope. Fine details of the wall structure and sculpture can be seen under the scanning electron microscope (magnification of 20,000 to 40,000×). The detailed structure of the wall (exine layer), and the number and arrangements of pores and furrows in the wall, are the diagnostic characters used in identification. Pollen is a key tool in reconstructing past vegetation and environments (palaeoecology), because the outer wall is both extremely resistant to decay and elaborately and beautifully constructed so that identification to species or family level is possible. Pollen of many plants is discharged into the air annually and falls into lakes and bogs as a "rain" which represents the surrounding vegetation. Many forest regions in Canada produce a total pollen fallout of 30,000 to 60,000 grains per cm2 annually, whereas tundra regions produce fewer than 1,000 grains per cm2 annually.
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Article

Pandemics in Canada

A pandemic is an outbreak of an infectious disease that affects a large proportion of the population in multiple countries or worldwide. Human populations have been affected by pandemics since ancient times. These include widespread outbreaks of plague, cholera, influenza and, more recently, HIV/AIDS and COVID-19. In order to slow or stop the spread of disease, governments implement public health measures that include testing, isolation and quarantine. In Canada, public health agencies at the federal, provincial and municipal levels play an important role in monitoring disease, advising governments and communicating to the public. Click here for definitions of key terms used in this article.
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Article

Pantonal

Pantonal (Institut de recherche Pantonal Inc).
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Article

Parasitology

Parasitology is a branch of biology dealing with organisms (animals or, rarely, plants) which live in or on other species (hosts) from which they derive nourishment. These organisms are called parasites. This rather simplistic definition includes some viruses, bacteria and protozoa, various kinds of worms and certain insects, ticks, mites and copepod crustaceans. Some parasites cause disease in humans and in domestic and wild animals, although most appear to have minimal effect on their hosts. Several have complex and fascinating developmental cycles in two or more hosts.
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