Search

Wesley Clover International's Alacrity Program operates at several locations globally to create new information and communication technology (ICT)–based companies supported by local investors. The in-country individuals selected as team members to build new companies are often recent bachelor's-level technology graduates with little or no business experience. To ensure success of the tech Start-ups built by such teams, it has been necessary to develop specialized, targeted training programs, accompanied by selective local mentoring. This article outlines the several organizational and training models used by the company to ensure the team behind each start-up has the necessary education, skills, and ongoing support for business success. [ABSTRACT FROM AUTHOR]

Anthropogenic stressors are the current drivers of loss of global biodiversity and deterioration of ecosystem function (e.g., primary production). However, it is debatable whether human stressors or associated changes in biodiversity better predict the impairment of ecosystem function. Variation in plankton communities during a whole-lake experiment (Lake 302S, Experimental Lakes Area, Canada) was examined to test whether the stressor treatment effect or subsequent stressor-independent variation in species richness best explained interannual variation in aggregate functional properties, such as productivity or net total biomass. Although significant “biodiversity – ecosystem function” relationships were detected, these correlations were confounded by the negative effect of experimental acidification on species richness. The stressor effect was removed by plotting functional properties against the residuals from the species richness – pH regressions, which generated either negative or nonsignificant relationships. The lack of significant stressor-independent positive relationships between functional properties and species richness highlights the potential greater importance of other mediating factors, such as interactions among multiple stressors, species identity, and altered trophic interactions, at the whole-ecosystem scale. [ABSTRACT FROM AUTHOR]

This article re-examines the problem of radical disunity after 1832. The main focus is on radical attitudes towards the second Melbourne ministry (1835–41) and its handling of the Canadian rebellions of 1837. Even when the government's imperial difficulties created a suitable opportunity to rekindle their reform campaign, radical leaders failed to co-operate effectively and made little headway in mobilizing and harnessing popular support. This defeat can be profitably explored through the experiences of Thomas Perronet Thompson (1783–1869), who emerged as one of the most energetic and strident critics of British policy in Canada during and after the rebellions. Despite his best efforts, Thompson was unable to win over other radical leaders or to attract a large following, a failure that highlights the wider constraints faced by radicalism in this era. [ABSTRACT FROM AUTHOR]

Summary1. The littoral microcrustacean community (Cladocera and Copepoda) was examined from 1989 to 1991 in a lake experimentally acidified to pH 4.5, and from 1992 to 1997 during the early stages of pH recovery. 2. Cladoceran abundance declined significantly from 1989 to 1991 (pH 4.5), but species richness did not change. Acantholeberis curvirostris, Simocephalus serrulatus, Latona spp. (Latona setifera, L. parviremis), and all species of chydorid Cladocera declined markedly in abundance while at pH 4.5. The abundance of cyclopoid copepods was low and Ceriodaphnia and calanoid copepods were absent. 3. Recovery of the community was subsequently monitored as pH was incrementally changed to a target pH 5.1 in 1992 and 1993, and to 5.8 in 1994–97. Species richness remained unchanged. Chydorid cladocerans remained at low abundance in 1992, and only Chydorus cf. brevilabris increased substantially from 1993 to 1996. Non-chydorid Cladocera increased in abundance in 1992, declined again in 1993, then gradually increased (mainly due to Ophryoxus gracilis) in 1994–96. All species declined in 1997 as minnows recolonized the lake. The calanoid copepod Leptodiaptomus minutus was present in low numbers in 1997. 4. The microcrustacean community in the littoral zone of Lake 302S has not yet shown consistent signs of recovery from acidification. [ABSTRACT FROM AUTHOR]

Reintroduction of functionally important species is considered a key strategy for restoring damaged ecosystems. However, the sudden reappearance of an extirpated species may have adverse ecological impacts, degrading ecosystem services. Therefore, we experimentally reintroduced the crayfish Orconectes virilis into a biologically recovering, formerly acidified Boreal Shield lake (Lake 302S, Experimental Lakes Area, Canada) to determine its effect on the littoral food web following a 17-year absence. In June 2004, a single-factor experimental design consisting of two treatment levels (crayfish-less control versus 1.8 introduced crayfish·m–2) was replicated five times for a total of 10 littoral cages (4 m2). Orconectes virilis significantly (P < 0.05) suppressed the total biomass of other benthic invertebrates by 70% primarily because of declines in larval damselflies and midges. In addition, crayfish reduced periphytic biomass by 90% (P < 0.001). Stable isotopic analyses of the mesocosm food webs further indicated that O. virilis likely functioned as an omnivore, exerting direct and possibly indirect effects on other invertebrates and periphyton. Our findings highlight how the reintroduction of O. virilis must be balanced with adequate fish predation to prevent this species from becoming an invader and negatively affecting the productive capacity of boreal lakes. [ABSTRACT FROM AUTHOR]

Canadian water bodies are presently experiencing fluctuations in orconectid crayfish ranges largely as a result of human activities. The range of Orconectes virilis, Canada’s most widespread crayfish, is expanding westward into previously uninhabited water bodies of Alberta. This species is also set to re-colonize watersheds in the eastern extent of its range as post-acidification recovery of aquatic ecosystems continues. In addition, the non-native Orconectes rusticus has invaded Central Canada. This species has the potential to rapidly invade boreal water bodies and out-compete native congeners, including O. virilis. Both these crayfish species are known to affect benthic ecosystems and their invasions may have adverse consequences for Canadian water bodies if left unchecked. Here we review the current documented distribution of O. virilis and O. rusticus in Canada, and identify the potential impacts that their invasion may have on boreal aquatic ecosystems. Finally, we consider options that resource managers might consider to contend with these invasions. [ABSTRACT FROM AUTHOR]

Assesses the recovery of lakes in Southeastern Canada from the effects of acidic deposition. Trends near Smelter sources; Factors influencing chemical recovery; Predictions of biological recovery.

Presents a study that determined the influence of spatial and temporal scale of acidification on the resilience of epilithic assemblages during chemical recovery of Canadian boreal lakes. Effects of anthropogenic acidification of boreal lakes on several environmental variables; Indicators of recovery in acidifed lakes; Comparison of experimental and atmospheric acidification of lakes; Details of study lakes and sampling protocols.

We analyzed the 21-yr dynamics of dissolved organic carbon (DOC) in 55 lakes during ice-free periods in five regions across eastern Canada in relation to total solar radiation (TSR), precipitation, air temperature, sulfate deposition (SO4), Southern Oscillation Index (SOI), North Atlantic Oscillation, and Pacific Decadal Oscillation (PDO). A synchronous pattern in DOC was found among lakes within each region; however, a synchronous pattern in DOC was not found among regions, except for Kejimkujik and Yarmouth. Long-term trends of increasing or decreasing DOC concentration were not evident except at the Experimental Lakes Area (ELA), where an increase in DOC correlated with a decrease in summer TSR and an increase in summer precipitation. Annual mean temperature increased at the Nova Scotia and Turkey Lakes Watershed regions (TLW) over the study period, but there was no corresponding change in DOC. TSR and precipitation were important explanatory variables across all regions, except for the TLW. Summer TSR, or annual TSR, had a negative relationship, while summer precipitation had a positive relationship with the temporal DOC pattern in all regions except TLW. TSR and precipitation explained 78%, 49%, and 84% of the variation in the long-term DOC patterns at Dorset, ELA, and Nova Scotia (NS) regions, respectively. In contrast, the long-term pattern in DOC at TLW was only weakly related to SOI and PDO. [ABSTRACT FROM AUTHOR]