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governmentOttawa, Ontario, Canada

Research output, citation impact, and the most-cited recent papers from Government of Canada (Canada). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
3.8K
Citations
135.9K
h-index
143
i10-index
2.0K
Also known as
Gouvernement de Sa MajestéGouvernement du CanadaGovernment of CanadaHer Majesty's Government

Top-cited papers from Government of Canada

Abscisic Acid: Emergence of a Core Signaling Network
Sean R. Cutler, Pedro L. Rodrı́guez, Ruth Finkelstein, Suzanne R. Abrams
2010· Annual Review of Plant Biology3.1Kdoi:10.1146/annurev-arplant-042809-112122

Abscisic acid (ABA) regulates numerous developmental processes and adaptive stress responses in plants. Many ABA signaling components have been identified, but their interconnections and a consensus on the structure of the ABA signaling network have eluded researchers. Recently, several advances have led to the identification of ABA receptors and their three-dimensional structures, and an understanding of how key regulatory phosphatase and kinase activities are controlled by ABA. A new model for ABA action has been proposed and validated, in which the soluble PYR/PYL/RCAR receptors function at the apex of a negative regulatory pathway to directly regulate PP2C phosphatases, which in turn directly regulate SnRK2 kinases. This model unifies many previously defined signaling components and highlights the importance of future work focused on defining the direct targets of SnRK2s and PP2Cs, dissecting the mechanisms of hormone interactions (i.e., cross talk) and defining connections between this new negative regulatory pathway and other factors implicated in ABA signaling.

Predicting relapse: A meta-analysis of sexual offender recidivism studies.
R. Karl Hanson, Monique T. Bussière
1998· Journal of Consulting and Clinical Psychology2.3Kdoi:10.1037/0022-006x.66.2.348

Evidence from 61 follow-up studies was examined to identify the factors most strongly related to recidivism among sexual offenders. On average, the sexual offense recidivism rate was low (13.4%; n = 23,393). There were, however, subgroups of offenders who recidivated at high rates. Sexual offense recidivism was best predicted by measures of sexual deviancy (e.g., deviant sexual preferences, prior sexual offenses) and, to a lesser extent, by general criminological factors (e.g., age, total prior offenses). Those offenders who failed to complete treatment were at higher risk for reoffending than those who completed treatment. The predictors of nonsexual violent recidivism and general (any) recidivism were similar to those predictors found among nonsexual criminals (e.g., prior violent offenses, age, juvenile deliquency). Our results suggest that applied risk assessments of sexual offenders should consider separately the offender's risk for sexual and nonsexual recidivism.

Eutrophication of lakes cannot be controlled by reducing nitrogen input: Results of a 37-year whole-ecosystem experiment
David W. Schindler, Robert E. Hecky, D. L. Findlay, M. P. Stainton +4 more
2008· Proceedings of the National Academy of Sciences1.7Kdoi:10.1073/pnas.0805108105

Lake 227, a small lake in the Precambrian Shield at the Experimental Lakes Area (ELA), has been fertilized for 37 years with constant annual inputs of phosphorus and decreasing inputs of nitrogen to test the theory that controlling nitrogen inputs can control eutrophication. For the final 16 years (1990-2005), the lake was fertilized with phosphorus alone. Reducing nitrogen inputs increasingly favored nitrogen-fixing cyanobacteria as a response by the phytoplankton community to extreme seasonal nitrogen limitation. Nitrogen fixation was sufficient to allow biomass to continue to be produced in proportion to phosphorus, and the lake remained highly eutrophic, despite showing indications of extreme nitrogen limitation seasonally. To reduce eutrophication, the focus of management must be on decreasing inputs of phosphorus.

Nutrient limitation of phytoplankton in freshwater and marine environments: A review of recent evidence on the effects of enrichment
Robert E. Hecky, Peter Kilham
1988· Limnology and Oceanography1.4Kdoi:10.4319/lo.1988.33.4_part_2.0796

Phytoplankton can become limited by the availability of nutrients when light and temperature are adequate and loss rates are not excessive. The current paradigms for nutrient limitations in freshwater, estuarine, and marine environments are quite different. A review of the experimental and observational data used to infer P or N limitation of phytoplankton growth indicates that P limitation in freshwater environments can be demonstrated rigorously at several hierarchical levels of system complexity, from algal cultures to whole lakes. A similarly rigorous demonstration of N limitation has not been achieved for marine waters. Therefore, we conclude that the extent and severity of N limitation in the marine environment remain an open question. Culture studies have established that internal cellular concentrations of nutrients determine phytoplankton growth rates, and these studies have shown that it is often difficult to relate growth rates to external concentrations, especially in natural situations. This should lead to a greater reliance on the composition of particulate matter and biomass‐based physiological rates to infer nutrient limitation. Such measurements have demonstrated their utility in a wide variety of freshwater and marine environments, and, most importantly, they can be applied to systems that are difficult to manipulate experimentally or budget accurately. Dissolved nutrient concentrations are most useful in determining nutrient loading rates of aquatic ecosystems. The relative proportions of nutrients supplied to phytoplankton can be a strong selective force shaping phytoplankton communities and affecting the biomass yield per unit of limiting nutrient.

Energetic Responses of Salmon to Temperature. A Study of Some Thermal Relations in the Physiology and Freshwater Ecology of Sockeye Salmon (<i>Oncorhynchus nerkd</i>)
John Brett
1971· American Zoologist1.1Kdoi:10.1093/icb/11.1.99

SYNOPSIS. Studies on the relation of temperature to tolerance, preference, metabolic rate, performance, circulation, and growth of sockeye salmon all point to a physiological optimum in the region of 15°C. Natural occurrence is limited in time and space at temperatures above 18°C despite being able to tolerate 24°C. Forms of physiological inadequacy can be demonstrated which account for such restrictions in distribution. Predictive power for locating and accounting for concentrations of young fish in thermally stratified lakes appeared to provide “proof” for the controlling influence of the physiological optimum temperature. Early literature on the ecology of sockeye supported this view. Recent studies using midwater trawls and sonar detection reveal a diurnal behavior pattern which points to a more subtle interaction of biotic andabiotic factors governing vertical distribution in which the controlling force appears to be bioenergetic efficiency. It is concluded that a mechanism of behavioral thermoregulation has evolved which favorably balances daily metabolic expenditures in order to conserve energy when food is limited.

Improving risk assessments for sex offenders: A comparison of three actuarial scales.
R. Karl Hanson, David J. Thornton
2000· Law and Human Behavior1.1Kdoi:10.1023/a:1005482921333

The study compared the predictive accuracy of three sex offender risk-assessment measures: the RRASOR (Hanson, 1997), Thornton's SACJ-Min (Grubin, 1998), and a new scale, Static-99, created by combining the items from the RRASOR and SACJ-Min. Predictive accuracy was tested using four diverse datasets drawn from Canada and the United Kingdom (total n = 1301). The RRASOR and the SACJ-Min showed roughly equivalent predictive accuracy, and the combination of the two scales was more accurate than either original scale. Static-99 showed moderate predictive accuracy for both sexual recidivism (r = 0.33, ROC area = 0.71) and violent (including sexual) recidivism (r = 0.32, ROC area = 0.69). The variation in the predictive accuracy of Static-99 across the four samples was no more than would be expected by chance.

Eutrophication and Recovery in Experimental Lakes: Implications for Lake Management
D. W. Schindler
1974· Science1.0Kdoi:10.1126/science.184.4139.897

Combinations of phosphorus, nitrogen, and carbon were added to several small lakes in northwestern Ontario, Canada, at rates similar to those in many culturally eutrophied lakes. Phosphate and nitrate caused rapid eutrophication. A similar result was obtained with phosphate, ammonia, and sucrose, but recovery was almost immediate when phosphate additions only were discontinued. When two basins of one lake were fertilized with equal amounts of nitrate and sucrose, and phosphorus was also added to one of the basins, the phosphateenriched basin quickly became highly eutrophic, while the basin receiving only nitrogen and carbon remained at prefertilization conditions. These results, and the high affinity of sediments for phosphorus indicate that rapid abatement of eutrophication may be expected to follow phosphorus control measures.

First Report of the Collaborative Outcome Data Project on the Effectiveness of Psychological Treatment for Sex Offenders
R. Karl Hanson, Arthur Gordon, A. I. Harris, Janice K. Marques +3 more
2002· Sexual Abuse870doi:10.1177/107906320201400207

This meta-analytic review examined the effectiveness of psychological treatment for sex offenders by summarizing data from 43 studies (combined n = 9,454). Averaged across all studies, the sexual offence recidivism rate was lower for the treatment groups (12.3%) than the comparison groups (16.8%, 38 studies, unweighted average). A similar pattern was found for general recidivism, although the overall rates were predictably higher (treatment 27.9%, comparison 39.2%, 30 studies). Current treatments (cognitive-behavioral, k = 13; systemic, k = 2) were associated with reductions in both sexual recidivism (from 17.4 to 9.9%) and general recidivism (from 51 to 32%). Older forms of treatment (operating prior to 1980) appeared to have little effect. Future directions for improving the quality of sex offender treatment outcome evaluations are discussed.

Where Should We Intervene?
R. Karl Hanson, A. I. Harris
2000· Criminal Justice and Behavior782doi:10.1177/0093854800027001002

Effective intervention with sexual offenders requires the targeting of appropriate risk factors. In this study, information on dynamic (changeable) risk factors was collected through interviews with community supervision officers and file reviews of 208 sexual offense recidivists and 201 nonrecidivists. The recidivists were generally considered to have poor social supports, attitudes tolerant of sexual assault, antisocial lifestyles, poor self-management strategies, and difficulties cooperating with supervision. The overall mood of the recidivists and nonrecidivists was similar, but the recidivists showed increased anger and subjective distress just before reoffending. The dynamic risk factors reported by the officers continued to be strongly associated with recidivism, even after controlling for preexisting differences in static risk factors. The factors identified in the interview data were reflected (to a lesser extent) in the officers' contemporaneous case notes, which suggests that the interview findings cannot be completely attributed to retrospective recall bias.

Effects of Acid Rain on Freshwater Ecosystems
D. W. Schindler
1988· Science663doi:10.1126/science.239.4836.149

Acid-vulnerable areas are more numerous and widespread than believed 7 years ago. Lakes and streams in acid-vulnerable areas of northeastern North America have suffered substantial declines in acid-neutralizing capacity, the worst cases resulting in biological damage. Many invertebrates are very sensitive to acidification, with some disappearing at pH values as high as 6.0. However, the recent rate of acidification of lakes is slower than once predicted, in part the result of decreases in sulfur oxide emissions. A discussion of some of the processes that have contributed to the acidification of lakes as well as those that have protected acid-sensitive freshwaters is presented. The author is in the Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba R3T 2N6, Canada.

Exercises for mechanical neck disorders
Anita Gross, Theresa Kay, Jean-Philippe Paquin, Samuel Blanchette +4 more
2015· Cochrane Database of Systematic Reviews600doi:10.1002/14651858.cd004250.pub5

BACKGROUND: Neck pain is common, disabling and costly. Exercise is one treatment approach. OBJECTIVES: To assess the effectiveness of exercises to improve pain, disability, function, patient satisfaction, quality of life and global perceived effect in adults with neck pain. SEARCH METHODS: We searched MEDLINE, MANTIS, ClinicalTrials.gov and three other computerized databases up to between January and May 2014 plus additional sources (reference checking, citation searching, contact with authors). SELECTION CRITERIA: We included randomized controlled trials (RCTs) comparing single therapeutic exercise with a control for adults suffering from neck pain with or without cervicogenic headache or radiculopathy. DATA COLLECTION AND ANALYSIS: Two review authors independently conducted trial selection, data extraction, 'Risk of bias' assessment and clinical relevance. The quality of the evidence was assessed using GRADE. Meta-analyses were performed for relative risk and standardized mean differences (SMD) with 95% confidence intervals (CIs) after judging clinical and statistical heterogeneity. MAIN RESULTS: Twenty-seven trials (2485 analyzed /3005 randomized participants) met our inclusion criteria.For acute neck pain only, no evidence was found.For chronic neck pain, moderate quality evidence supports 1) cervico-scapulothoracic and upper extremity strength training to improve pain of a moderate to large amount immediately post treatment [pooled SMD (SMDp) -0.71 (95% CI: -1.33 to -0.10)] and at short-term follow-up; 2) scapulothoracic and upper extremity endurance training for slight beneficial effect on pain at immediate post treatment and short-term follow-up; 3) combined cervical, shoulder and scapulothoracic strengthening and stretching exercises varied from a small to large magnitude of beneficial effect on pain at immediate post treatment [SMDp -0.33 (95% CI: -0.55 to -0.10)] and up to long-term follow-up and a medium magnitude of effect improving function at both immediate post treatment and at short-term follow-up [SMDp -0.45 (95%CI: -0.72 to -0.18)]; 4) cervico-scapulothoracic strengthening/stabilization exercises to improve pain and function at intermediate term [SMDp -14.90 (95% CI:-22.40 to -7.39)]; 5) Mindfulness exercises (Qigong) minimally improved function but not global perceived effect at short term. Low evidence suggests 1) breathing exercises; 2) general fitness training; 3) stretching alone; and 4) feedback exercises combined with pattern synchronization may not change pain or function at immediate post treatment to short-term follow-up. Very low evidence suggests neuromuscular eye-neck co-ordination/proprioceptive exercises may improve pain and function at short-term follow-up.For chronic cervicogenic headache, moderate quality evidence supports static-dynamic cervico-scapulothoracic strengthening/endurance exercises including pressure biofeedback immediate post treatment and probably improves pain, function and global perceived effect at long-term follow-up. Low grade evidence supports sustained natural apophyseal glides (SNAG) exercises.For acute radiculopathy, low quality evidence suggests a small benefit for pain reduction at immediate post treatment with cervical stretch/strengthening/stabilization exercises. AUTHORS' CONCLUSIONS: No high quality evidence was found, indicating that there is still uncertainty about the effectiveness of exercise for neck pain. Using specific strengthening exercises as a part of routine practice for chronic neck pain, cervicogenic headache and radiculopathy may be beneficial. Research showed the use of strengthening and endurance exercises for the cervico-scapulothoracic and shoulder may be beneficial in reducing pain and improving function. However, when only stretching exercises were used no beneficial effects may be expected. Future research should explore optimal dosage.

Global-Scale Environmental Effects of Hydrological Alterations: Introduction
David M. Rosenberg, P. McCully, Catherine M. Pringle
2000· BioScience563doi:10.1641/0006-3568(2000)050[0746:gseeoh]2.0.co;2

Ubiquitous hydrological alterations-dam construction and associated water diversion, exploitation of groundwater aquifers, stream channelization, and intercatchment water transfer-are producing global-scale effects on the environment. The articles in this special issue of BioScience highlight the cumulative effects of hydrological alterations associated with dam and reservoir development. Such information is critical for deciding whether, when, and where the next major hydrological project will be built; it can also warn us about impending environmental impacts.

Urban Trees and Human Health: A Scoping Review
Kathleen L. Wolf, Sharon T. Lam, Jennifer McKeen, Gregory R. A. Richardson +2 more
2020· International Journal of Environmental Research and Public Health443doi:10.3390/ijerph17124371

The urban forest is a green infrastructure system that delivers multiple environmental, economic, social and health services, and functions in cities. Environmental benefits of urban trees are well understood, but no review to date has examined how urban trees affect human health. This review provides a comprehensive summary of existing literature on the health impacts of urban trees that can inform future research, policy, and nature-based public health interventions. A systematic search used keywords representing human health, environmental health, and urban forestry. Following screening and appraisal of several thousand articles, 201 studies were conceptually sorted into a three-part framework. Reducing Harm, representing 41% of studies, includes topics such as air pollution, ultraviolet radiation, heat exposure, and pollen. Restoring Capacities, at 31%, includes attention restoration, mental health, stress reduction, and clinical outcomes. Building Capacities, at 28%, includes topics such as birth outcomes, active living, and weight status. The studies that were reviewed show substantial heterogeneity in purpose and method yet indicate important health outcomes associated with people's exposure to trees. This review will help inform future research and practice, and demonstrates why urban forest planning and management should strategically promote trees as a social determinant of public health.

A framework for selecting a suite of indicators for fisheries management
Jake Rice, Marie-Joëlle Rochet
2005· ICES Journal of Marine Science428doi:10.1016/j.icesjms.2005.01.003

Abstract We develop a framework for the objective selection of a suite of indicators for use in fisheries management. The framework encompasses eight steps, and provides guidance on pitfalls to be avoided at each step. Step 1 identifies user groups and their needs, featuring the setting of operational objectives, and Step 2 identifies a corresponding list of candidate indicators. Step 3 assigns weights to nine screening criteria for the candidate indicators: concreteness, theoretical basis, public awareness, cost, measurement, historic data, sensitivity, responsiveness, and specificity. Step 4 scores the indicators against the criteria, and Step 5 summarizes the results. Steps 3–5 offer technical aspects on which guidance is provided, including scoring standards for criteria and a generalized method for applying the standards when scoring individual indicators. Multi-criterion summarization methods are recommended for most applications. Steps 6 and 7 are concerned with deciding how many indicators are needed, and making the final selection of complementary suites of indicators. Ordinarily, these steps are done interactively with the users of the indicators, thus providing guidance on process rather than technical approach. Step 8 is the clear presentation to all users of the information contained. The discussion also includes the special case in which indicators are used in formal decision rules.

Addressing the endogeneity dilemma in operations management research: Theoretical, empirical, and pragmatic considerations
Mikko Ketokivi, Cameron N. McIntosh
2017· Journal of Operations Management428doi:10.1016/j.jom.2017.05.001

Abstract In this paper, we examine the problem of endogeneity in the context of operations management research. Whereas the extant literature has focused primarily on the statistical aspect of the problem, a comprehensive treatment requires an examination of theoretical and pragmatic considerations as complements. The prevailing problem with the focus on statistical techniques is that the standards tend to be derived from idealizations: the correlation between a regressor and a disturbance term must be exactly zero, or the analysis will be invalid. In actual empirical research settings, such a knife‐edge assumption can never be satisfied, indeed it cannot even be directly tested. Idealizations are useful in helping us understand what it would take to eliminate endogeneity, but when applied directly and unconditionally, they lead to unreasonable standards that may unnecessarily stifle substantive inquiry. We believe that it is far more productive and meaningful to ask: “What can we realistically expect empirical scientists to be able to achieve?” To this end, we cover and revisit some of the general technical material on endogeneity, paying special attention to the idiosyncrasies of operations management research and what could constitute reasonable criteria for addressing endogeneity in empirical operations management studies.

Can scientists and policy makers work together?: Table 1
Bernard C. K. Choi, Tikki Pang, Vivian Lin, Pekka Puska +4 more
2005· Journal of Epidemiology & Community Health395doi:10.1136/jech.2004.031765

This paper addresses a fundamental question in evidence based policy making--can scientists and policy makers work together? It first provides a scenario outlining the different mentalities and imperatives of scientists and policy makers, and then discusses various issues and solutions relating to whether and how scientists and policy makers can work together. Scientists and policy makers have different goals, attitudes toward information, languages, perception of time, and career paths. Important issues affecting their working together include lack of mutual trust and respect, different views on the production and use of evidence, different accountabilities, and whether there should be a link between science and policy. The suggested solutions include providing new incentives to encourage scientists and policy makers to work together, using knowledge brokers (translational scientists), making organisational changes, defining research in a broader sense, re-defining the starting point for knowledge transfer, expanding the accountability horizon, and finally, acknowledging the complexity of policy making. It is hoped that further discussion and debate on the partnership idea, the need for incentives, recognising the incompatibility problems, the role of civil society, and other related themes will lead to new opportunities for further advancing evidence based policy and practice.

FURTHER MEASUREMENTS OF PRIMARY PRODUCTION USING A LARGE‐VOLUME PLASTIC SPHERE
Naval J. Antia, C. D. McAllister, TIMOTHY R. PARSONS, K. Stephens +1 more
1963· Limnology and Oceanography387doi:10.4319/lo.1963.8.2.0166

The experiment described by McAllister, et al. (1961), in which a phytoplankton bloom was induced to occur in a free‐floating 20‐ft diameter thin transparent plastic sphere has been repeated. Daily measurements were made of nutrients, particulate matter, and photosynthetic rates with less frequent assays for vitamins and dissolved organic matter. In situ light was recorded by a bolometer. The experiment was prolonged to 100 days to study phytoplankton decay, most of this period being in the dark. The phytoplankton consisted mainly of 6 species of diatom and one large dinoflagellate. The mean composition of this crop at various stages of its development is reported by ratios involving chlorophyll a and particulate organic carbon. A detailed discussion is given of the findings of the experiment which, in general, confirmed those of the earlier work and yielded, in addition, valuable new information. The plant cells excreted 35–40% of their organic matter during growth. The C 14 method of measuring photosynthesis gave results agreeing well with the production of particulate carbon. The growth kinetics of the bloom were dominated by the constancy of the mean cell division rates which were relatively independent of temperature and light. The rate of photosynthesis per unit chlorophyll was also remarkably constant and not proportional to light intensity, cells developing a highly efficient photosynthetic mechanism with respect to available radiant energy. The mean chemical composition of a cell changed after depletion of nutrients from the surrounding water. The carbon, protein, chlorophyll a and phosphorus decreased. The silicon and lipid contents remained nearly constant and the carbohydrate increased. During the decay period over half the particulate phosphorus was remineralized in 2 weeks. Silicon returned to solution more slowly but at a constant rate. There was no significant nitrification even after 75 days. The consumption of oxygen occurred mainly from the oxidation of “dissolved” organic matter and not from the interaction of oxygen with particulate material. The latter may have been important as a surface for bacteria. The evolution rate of carbon dioxide was constant with time but proceeded with a variable RQ, which was around 0.5 immediately after the bloom but increased to nearly 2 in the “old” water present at the beginning and end of the experiment.

ON ESTIMATING ANNUAL PRODUCTION
Andrew Hamilton
1969· Limnology and Oceanography363doi:10.4319/lo.1969.14.5.0771

The method of Hynes and Coleman is modified to make it more adaptable and more consistent with their underlying assumptions. If most organisms comprising a community are univoltine and have approximately the same maximum size, the average standing crop can be used to obtain a realistic estimate of annual production. The size frequency distribution can be regarded as a first estimate of an “average cohort” when the number of “average cohorts” equals the number of size classes through which the organisms grow. If growth, in terms of the size units used, is assumed to be linear, then numerical differences in adjacent size classes can be attributed to mortality. When all size classes are considered together, the effect of nonlinear growth on the estimate of annual production is not large. In contrast, a serious error is introduced if the organisms are not univoltine. When the growth pattern and generation time are known, it is relatively simple to modify the average size frequency distribution to improve the estimate of the “average cohort” and hence improve the estimate of annual production. A reply to the criticisms of Fager is included.

PAHs, PCBs, PCNs, Organochlorine Pesticides, Synthetic Musks, and Polychlorinated <i>n</i>-Alkanes in U.K. Sewage Sludge:  Survey Results and Implications
Joanna L. Stevens, Grant L. Northcott, Gary A. Stern, Gregg T. Tomy +1 more
2002· Environmental Science & Technology356doi:10.1021/es020161y

A survey of the digested sludge from 14 U.K. wastewater treatment plants was carried out to obtain contemporary U.K. data on the concentrations of certain classes of persistent organic compounds for which data are scarce and to assess whether U.K. sludge was likely to comply with the sludge limits for PCBs and PAHs proposed by the European Union. Total PAH (24 compounds) concentrations ranged from 67 to 370 mg/kg dw, in line with data from other countries; all the samples would exceed the proposed EU limit. Total PCB concentrations were 110-440 microg/kg dw, well below the proposed EU limit. Total PCN concentrations ranged from 50 to 190 microg/kg. Total synthetic musk concentrations ranged from 2.1 to 86 mg/kg dw; there were a few very high concentrations of HHCB and AHTN in the samples. Total concentrations of the short- and medium-chained polychlorinated alkanes ranged between 7 and 200 mg/kg and between 30 and 9700 mg/kg, respectively. These very high concentrations are indicative of chemicals with numerous and ongoing diffuse sources.

Addressing Attribution through Contribution Analysis: Using Performance Measures Sensibly
John Mayne
2001· Canadian Journal of Program Evaluation342doi:10.3138/cjpe.016.001

Abstract: The changing culture of public administration involves accountability for results and outcomes. This article suggests that performance measurement can address such attribution questions. Contribution analysis has a major role to play in helping managers, researchers, and policymakers to arrive at conclusions about the contribution their program has made to particular outcomes. The article describes the steps necessary to produce a credible contribution story.