Simulating the effect of quarantine on the spread of the 1918–19 flu in Central Canada

Quarantine is often proposed and sometimes used to control the spread of infectious diseases through a human population. Yet there is usually little or no information on the effectiveness of attempting to quarantine humans that is not of an anecdotal or conjectural nature. This paper describes how a compartmental model for the geographic spread of infectious diseases can be used to address the potential effectiveness of human quarantine. The model is applied to data from the historical record in central Canada around the time of the 1918–19 influenza epidemic. Information on the daily mobility patterns of individuals engaged in the fur trade throughout the region prior to, during, and immediately after the epidemic are used to determine whether rates of travel were affected by informal quarantine policies imposed by community leaders. The model is then used to assess the impact of observed differences in travel on the spread of the epidemic. Results show that when mobility rates are very low, as in this region, quarantine practices must be highly effective before they alter disease patterns significantly. Simulation results suggest, though, that effectiveness varies depending on when the limitation on travel between communities is implemented and how long it lasts, and that a policy of introducing quarantine at the earliest possible time may not always lead to the greatest reduction in cases of a disease.     

Zooplankton communities of the Arctic’s Canada Basin: the contribution by smaller taxa

Zooplankton was sampled at ten stations in the Canada Basin during August 2002 using both 53- and 236-m mesh nets to examine the contribution by smaller and less studied species. Copepod nauplii, the copepods Oithona similis, Oncaea borealis and Microcalanus pygmaeus, and the larvacean Fritillaria borealis typica dominated the upper 100 m of the water column numerically, while biomass was dominated by the copepods Calanus hyperboreus, Calanus glacialis and Paraeuchaeta glacialis, and the chaetognath Eukrohnia hamata. Zooplankton biomass ranged from 3.7 to 14.5 mg AFDW m^–3, with a mean of 9.6 mg AFDW m^–3 . While the three microcopepods contributed less than 5% of the biomass, estimates of their potential growth rates suggest they might contribute upwards of 25% of the metazoan zooplankton production. The true rates of growth and development of these microcopepods in the Arctic need to be determined to conclusively ascertain their importance.     

Chitinozoan zonation of the Late Ordovician and the Early Silurian of the island of Anticosti, Québec, Canada

A reappraisal of chitinozoan distribution across the Ordovician-Silurian boundary on the Island of Anticosti has led to the recognition of a new zone, the Ancyrochitina ellisbayensis biozone, in the uppermost part of the Ellis Bay Formation. This biozone lies between the well defined Upper Ordovician Spinachitina taugourdeaui biozone and the lowest Silurian (Rhuddanian) Plectochitina nodifera biozone of the Becscie Formation. The occurrence of such diagnostic species as P. nodifera, Belonechitina postrobusta, Conochitina electa and Ancyrochitina ramosaspina in the Lower Silurian of Anticosti points to a close similarity to faunas in Estonia and north Latvia and indicates an age ranging from the Parakidograptus acuminatus to the Coronograptus cyphus in terms of graptolite zones. The chitinozoan biozonation harmonizes with that based on conodonts and, to a lesser extent, with the known graptolite faunal succession. Five new species: Ancyrochitina ellisbayensis sp. nov., Clathrochitina postconcinna sp. nov., Conochitina gunriveris sp. nov., Clathrochitina perexilis sp. nov., Bursachitina basiconcava sp. nov. and three species in open nomenclature are described.     

Canada and China working together in the Nature Reserves of Inner Mongolia Autonomous Region

The environment and its natural resources are one of the richest treasures in the world. The lands, forests, lakes and rivers are not only beautiful spaces in the world, but these ecosystems are the basis of life for all the people and creatures who inhabit the earth. As inhabitants of the earth, we all have a responsibility to take care of these important resources-to protect our biological diversity-for ourselves, for future generations and for the many other creatures that we share the world with. Indeed, as stewards of the environment we must ensure that our actions, and those of the people around us, are not harmful or damaging to the earth.     

For what purpose the arts? An analysis of the mission statements of urban arts high schools in Canada and the United States

While general arts programs have declined in many schools across the United States and Canada, the number of specialized art programs in public secondary schools has swelled since the 1980s. While this increase is often celebrated by arts educators, questions about the justification of specialized arts programs are rarely raised, and their value is often taken for granted. In this article, we examine the mission statements of eighty-four specialized arts programs across two countries to examine the ideas, values, and commitments that are expressed in these public statements. In addition to a close thematic analysis, we describe how these mission statements reflect different conceptions of the role of the arts in education and consider the ways in which arguments that seek to broaden access to the arts are combined with the goal of serving a narrow subset of the student population. We argue that analyzing mission statements provides a clearer picture of the ideas that shape these programs, and that in order to foster an informed public conversation about the purpose and value of an education in the arts, educators committed to the arts must engage in this serious discussion.     

Does Climate or Habitat Affect the Frequency of Cooperative Brood Rearing in Canada Geese?

Canada geese ( Branta canadensis ) are unusual because individuals use either of two different brood-rearing behaviors: cooperative broods (two or more merged broods attended by more than three parents) or two-parent families. We tested whether cooperative broods form in response to habitat or climatic conditions by examining variation in cooperative brood frequencies among Canada geese nesting in Connecticut from 1982 to 1996. Percent of goslings raised in cooperative broods ranged from 0 to 100% at a given site in different years, but the pattern of annual variation was different at each site. The sites were in close proximity to each other and had similar climates; thus, the differences in annual variation among sites was not likely to be a response to climatic conditions. Cooperative brood frequencies also varied among sites in each individual year, but sites with the most gang brooding in one year often had the least the next. Such would not be expected if gang brooding occurred in response to non-ephemeral habitat characteristics. Sites where gang brooding occurred and where it did not have similar food resources and predation risks. These findings failed to support the hypotheses that gang broods form in response to food competition or predation. Sites where gang broods occurred had more parent geese and more goslings than sites where they did not occur. Furthermore, the proportion of goslings raised in gang broods was correlated with the number of goslings and parents at the site. Our results support the hypothesis that gang broods form from the inadvertent mixing of goslings. This single factor, however, was not sufficient to account for all of the observed variation in gang brooding frequencies.     

Quaternary (Flandrian?) dinoflagellate cysts from the Grand Banks,off Newfoundland,Canada

A well-preserved assemblage of dinoflagellate cysts, probably of Flandrian age, was recovered from two piston cores on the Grand Banks, off Newfoundland, Canada. The assemblage, dominated by the dinoflagellate cyst species Operculodinium centrocarpum, is regarded as a mixed Gulf Stream/North Atlantic Drift—Labrador current association.     

Comparison of black–white disparities in preterm birth between Canada and the United States

Background:

A higher risk of preterm birth among black women than among white women is well established in the United States. We compared differences in preterm birth between non-Hispanic black and white women in Canada and the US, hypothesizing that disparities would be less extreme in Canada given the different historical experiences of black populations and Canada’s universal health care system.

Methods:

Using data on singleton live births in Canada and the US for 2004–2006, we estimated crude and adjusted risk ratios and risk differences in preterm birth (< 37 wk) and very preterm birth (< 32 wk) among non-Hispanic black versus non-Hispanic white women in each country. Adjusted models for the US were standardized to the covariate distribution of the Canadian cohort.

Results:

In Canada, 8.9% and 5.9% of infants born to black and white mothers, respectively, were preterm; the corresponding figures in the US were 12.7% and 8.0%. Crude risk ratios for preterm birth among black women relative to white women were 1.49 (95% confidence interval [CI] 1.32 to 1.66) in Canada and 1.57 (95% CI 1.56 to 1.58) in the US (p value for heterogeneity [p_H] = 0.3). The crude risk differences for preterm birth were 2.94 (95% CI 1.91 to 3.96) in Canada and 4.63 (95% CI 4.56 to 4.70) in the US (p_H = 0.003). Adjusted risk ratios for preterm birth (p_H = 0.1) were slightly higher in Canada than in the US, whereas adjusted risk differences were similar in both countries. Similar patterns were observed for racial disparities in very preterm birth.

Interpretation:

Relative disparities in preterm birth and very preterm birth between non-Hispanic black and white women were similar in magnitude in Canada and the US. Absolute disparities were smaller in Canada, which reflects a lower overall risk of preterm birth in Canada than in the US in both black and white populations.In the United States, a higher risk of preterm birth among black women than among white women is well established.^1–3 This racial disparity is of great concern because preterm birth is a leading cause of perinatal mortality and is predictive of developmental problems and adverse health outcomes later in life.⁴ The underlying causes of the racial disparity in preterm birth in the US are not well understood, although research has suggested contributing roles for a wide range of factors, including socioeconomic disadvantage,⁵ poor neighbourhood conditions (e.g., poverty, crime),^5,6 lack of access to health care,⁷ psychosocial stress,⁸ racial discrimination⁹ and adverse health behaviours.¹⁰Rates of preterm birth have consistently been lower in Canada than in the US.^11,12 However, in contrast to the US, little is known about differences in rates by race or ethnicity in Canada. There is evidence that African-born and Caribbean-born women in the provinces of Quebec and Ontario have higher rates of preterm birth than Canadian-born women.^13–15 Although the magnitude of these differences is smaller than the disparity in preterm births between black and white women in the US,¹⁶ foreign-born black women in the US have been found to be at lower risk of preterm birth than US-born black women.^17,18In both Canada and the US, socioeconomic conditions at both individual and neighbourhood levels are important predictors of preterm birth.^19–21 Although the income gap between black and white people is markedly smaller in Canada than in the US,²² black populations in both countries have lower education levels, higher unemployment rates and a greater likelihood of living in low-quality neighbourhoods compared with white populations.²³ Canada and the US share similar social and economic influences, yet the historical experiences of black populations and the social welfare systems (e.g., universal health care) are quite different in the 2 countries. Black people constitute about 13% of the total US population, but only about 3% of the Canadian population.^24,25 The overwhelming majority of Canada’s black population are immigrants who entered the country after 1960 and their descendants, whereas more than 85% of black Americans can trace their ancestry 3 or more generations in the US, with most being descendants of slaves.²²The objectives of our study are twofold. First, using data from a new cohort linking birth registrations with information from the 2006 Canadian long-form census, we present Canada-wide estimates of differences in preterm birth rates between black and white populations. Second, we use comparable methodology to compare racial differences in preterm birth rates between Canada and the US. Given different historical experiences of black populations in the 2 countries, as well as Canada’s commitment to universal health care and its general perception as a more egalitarian society than the US,²² we hypothesized that we would observe smaller racial disparities in the rates in Canada than in the US.     

“Föhn illness” and human biometeorology in the Chinook area of Canada

Literature on the nature and possible causes of föhn illness is reviewed. Seven physiological and psychological aspects of human well-being were solicited from 1828 residents of southern Alberta by telephone interview. Data were evaluated to determine if well-being was weather related. Meteorological parameters included eight 48-h weather types, temperature, humidity, wind and pressure. The expected increase in föhn illness symptoms during the frequent warm chinook and decrease at times of cold non-chinook weather were not present. However, with the cool chinook (temperature slightly below freezing) many people claimed additional irritability and, to a lesser extent, more pain in their joints, headaches and nervousness. Several adverse symptoms were positively correlated with wind velocity. However, no widespread chinook illness comparable to the föhn illness was found.     

Northward migrating trees establish in treefall gaps at the northern limit of the temperate–boreal ecotone, Ontario, Canada

Climate change is expected to promote migration of species. In ecotones, areas of ecological tension, disturbances may provide opportunities for some migrating species to establish in otherwise competitive environments. The size of and time since disturbance may determine the establishment ability of these species. We investigated gap dynamics of an old-growth red pine (Pinus resinosa Sol. ex Aiton) forest in the Great Lakes–St. Lawrence forest in northern Ontario, Canada, a transition zone between temperate and boreal forest. We investigated the effects of gaps of different sizes and ages on tree species abundance and basal area. Our results show that tree species from the temperate forest further south, such as red maple (Acer rubrum L.), red oak (Quercus rubra L.), and white pine (Pinus strobus L.), establish more often in large, old gaps; however, tree species that have more northern distributions, such as black spruce (Picea mariana Mill.), paper birch (Betula papyrifera Marsh.), and red pine show no difference in establishment ability with gap size or age. These differences in composition could not be attributed to autogenic succession. We conclude that treefall gaps in this forest facilitate the establishment of northward migrating species, potentially providing a pathway for future forest migration in response to recent changes in climate.     

Waiting for children��s surgery in Canada: the Canadian Paediatric Surgical Wait Times project

Background

In addition to possibly prolonged suffering and anxiety, extended waits for children’s surgery beyond critical developmental periods has potential for lifelong impact. The goal of this study was to determine the duration of waits for surgery for children and youth at Canadian paediatric academic health sciences centres using clinically-derived access targets (i.e., the maximum acceptable waiting periods for completion of specific types of surgery) as used in this Canadian Paediatric Surgical Wait Times project.

Methods

We prospectively applied standardized wait-time targets for surgery, created by nominal-group consensus expert panels, to pediatric patients at children’s health sciences centres across Canada with decision-to-treat dates of Sept. 1, 2007 or later. From Jan. 1 to Dec. 30, 2009, patients’ actual wait times were compared with their target wait times to determine the percentage of patients receiving surgery after the target waiting period.

Results

Overall, 27% of pediatric patients from across Canada (17411 of 64012) received their surgery after their standardized target waiting period. Dentistry, ophthalmology, plastic surgery and cancer surgery showed the highest percentages of surgeries completed past target.

Interpretation

Many children wait too long for surgery in Canada. Specific attention is required, in particular, in dentistry, ophthalmology, plastic surgery and cancer care, to address children’s wait times for surgery. Improved access may be realized with use of national wait-time targets.Prolonged wait times for care are often a concern in publicly funded health care systems.¹ Canadian governments have made the reduction of wait times a priority.^2,3 A Canadian federal–provincial accord, called the 2004 10-Year Plan to Strengthen Health Care, included a $5.5 billion wait-times reduction fund to help provincial and territorial governments reduce wait times in the five priority areas, which are cancer care, cardiac care, diagnostic imaging, joint replacement and sight restoration.³The focus of the fund, however, was almost exclusively relevant to adults, omitting Canada’s children and youth, who represent more than one-quarter of the Canadian population⁴ from the wait-time reduction priorities. To address wait times, governments in Canada have established central targets, such as the recommendation that surgery should be performed within six months of the decision to treat.² Although this approach is uniform and explicit, urgent surgery often requires a shorter time frame. An alternative approach to central targets is to have clinicians develop clinically derived access targets (i.e., maximum acceptable waiting periods for the completion of specific types of surgery).People are often surprised to learn that children wait for surgery just like adults.⁵ In addition to the possibility of prolonged suffering and anxiety that is typical of extended waits, surgery in children must sometimes be performed at critical developmental periods.⁶ Furthermore, adverse effects of extended waits may have lifelong impact, which magnifies the importance of measuring and addressing wait times in this vulnerable population. In 2006, the Pediatric Surgical Chiefs of Canada agreed to adopt standardized pediatric surgical wait-time access targets and resolved to measure the wait times for children’s surgeries. Thus, the Canadian Paediatric Surgical Wait Times project was founded as an unprecedented national collaborative effort. The goal of the project was to determine the duration of waits for surgery for children and youth at Canadian children’s centres in all surgical subspecialties, using clinically derived access targets.     

“Grateful” subjects: class and capital at the border in Philippine–Canada migration

This paper considers how Philippine migrants prepare themselves and are prepared by others for emigration to Canada. In particular, it emphasizes how class-differentiated migrants are rendered socially homogenous as they are encouraged to be “grateful” transnational citizen subjects throughout their migration trajectories, commencing with initial decisions to migrate. Preparations for migration include individual decisions to increase marketability by acquiring particular kinds of skill sets matched to one of a variety of immigration streams. Despite such individual projects, the inequalities associated with gendered and racialized characteristics of Philippine migration trajectories and class dynamics are enduring for many migrants, though not all. Historical structural processes shaping the contours of global migration in the example of Philippine–Canada migration are compounded by the contradictory practices and outcomes associated with various preparations for migration. Current reforms to Canada’s immigration system to a “just-in-time” model promise to cause major disruptions to long-held migrant plans. Meanwhile, migrants are preconditioned to accept uncritically the multiple forms of subordination encouraged through the policies of multiple states and to accommodate themselves to new immigrant/citizen social identities which are devalued in a multiplicity of ways. This paper shows how, through the collusion of agents that migrants encounter in multiple sites, the disciplining of mobile citizens becomes more formalized and the contradictions between migrant ambition and neoliberal imperatives more visible.     

Exploratory multiscale analysis of the fish assemblages and habitats of the lower St. Lawrence River,Québec,Canada

This work presents a multiscale analysis of the fish diversity of the lower St. Lawrence River which flows from the Laurentian Great Lakes of North America. A database of about 14,000 fish sampling stations from the lower St. Lawrence is linked to five different habitat maps of the study area: hydrographical units, water masses, depth, sediment type and wetland type. We hypothesize that species turnover (beta diversity) will be significant among these habitat maps. For each map, we calculate a UPGMA dendrogram based on the Jaccard coefficient of similarity in species occurrences as a first assemblage–habitat model. A randomization test is then used to identify the significant dendrograms from which we infer fish assemblages. We then show that many species are actually selecting or avoiding habitats. Finally, species selecting particular habitats are described by some selected ecological traits that are expected to occur frequently in those habitats. We found assemblages for the hydrographical units but not for the water masses. The fluvial section is selected by many stenohaline and some euryhaline species, while the freshwater estuary and the brackish estuary are only selected by euryhaline species. In the fluvial section at the hydrographical unit scale, many species associated with lentic habitats are limnophilic and more vegetation-dependent while many species selecting lotic habitats are rheophilic insectivorous species. Significant assemblages are defined for depth, sediment type and wetland type. Taken together, we found strong empirical evidence of a diverse actively selecting littoral assemblage of small, low mobility fishes opposing a channel assemblage of larger, more mobile fishes.     

Health of the Land,Health of the People: A Case Study on Gwich’in Berry Harvesting in Northern Canada

Many Aboriginal groups, in northern Canada and elsewhere, recognize the strong relationship between the health and well-being of people and environment. Western science, including theory and literature related to forest ecosystem management, has been slow to recognize the complex and diverse values that Aboriginal people associate with their lands and resources. Through case study research on the berry-harvesting practices of Gwich’in women from the community of Fort McPherson, Northwest Territories, Canada, we investigated the values that Teetl’it Gwich’in women associate with the land or nan kak. Nine different values, as well as a set of detailed measures, were identified during the research, including individual preference and well-being, family well-being, social connectivity, cultural continuity, land and resource use, stewardship, self-government, and spirituality. The commercial value of berries was not identified as important to women. This interdisciplinary research has the potential to contribute to several bodies of literature including that on social-ecological systems.     

Downstream variations of phytoplankton in the St.Lawrence River (Québec, Canada)

Longitudinal variations of phytoplankton biomass and composition were assessed in a 250 km-long section of the St.Lawrence River, which alternately runs through narrow (< 2 km) river cross sections and wide (up to 10 km) fluvial lakes. In the main river stem, concentrations of suspended matter and total phosphorus increased with distance downstream, whereas light penetration decreased. Seasonal changes in plankton composition and biomass were more important than those resulting from differences in water mass (tributary) of origin. Sampling at three cross river sections and in two fluvial lakes showed a progressive downstream decrease in phytoplankton biomass and changes in size structure and taxonomic composition. River plankton was primarily composed of small (< 10 µm equivalent spherical diameter), truly planktonic cells belonging to Cryptophyceae and diatoms, with Chlorophyceae in summer. Plankton sampled in summer among rooted macrophytes in fluvial lakes exhibited a higher biomass of resuspended periphytic algae than in the main river stem, which contributed slightly to downstream phytoplankton biomass.Successive river cross sections always shared about 50% of their taxa, indicating a rapid downstream transport of algae within the main water mass. However, the proportion of species common to all cross sections was highest during the spring freshet, and lowest during summer low discharge, likely resulting from the development of a distinct flora in fluvial lakes during summer. Conversely, about 30% of the identified taxa were exclusive to a cross section and were replaced by others occurring downstream. Overall, phytoplankton composition along the St.Lawrence River is primarily controlled by advective forces, which result in a homogeneous flora in the main river stem, with a local contribution of resuspended periphyton from fluvial lakes.     

Are legislative frameworks in Canada and Ontario up to the task of addressing invasive alien species?

As a signatory to the international Convention on Biological Diversity (CBD), Canada has committed to prevent, control, and eradicate invasive alien species (IAS). Yet, despite developing policy on biodiversity and IAS, the federal government has been criticized for its inaction on biological invasions over the past decade. In Canada’s most populous province, Ontario, similar concerns have been raised about the provincial government’s approach to dealing with IAS. The ongoing criticism of government response suggests that an effective legislative framework to guide and coordinate action on IAS may be lacking in Canada. In this paper, we examined how well existing legislation at the federal and Ontario levels addresses IAS threats, and thus contributes to CBD commitments. We reviewed a total of 98 pieces of legislation, comprised of 55 federal acts, two federal omnibus bills, and 41 Ontario acts. Of these, 20 federal and 12 Ontario acts were found to cover IAS either intentionally or incidentally, but IAS was not the central focus of most legislation. No consistent terminology existed across legislation referring to IAS, further highlighting a lack of focus on the issue. Legislation on IAS was administered by several different ministries both federally and in Ontario, but coordination of action among agencies was not explicitly addressed in laws and regulations. While many acts provided broad powers of enforcement, most provisions were not directly linked to IAS prevention and management. In general, Canada’s legislative framework on IAS is fragmented, and this complicates the development of a coordinated approach to the problem.