A comparison of taxon co-occurrence patterns for macro- and microorganisms

We examine co-occurrence patterns of microorganisms to evaluate community assembly "rules". We use methods previously applied to macroorganisms, both to evaluate their applicability to microorganisms and to allow comparison of co-occurrence patterns observed in microorganisms to those found in macroorganisms. We use a null model analysis of 124 incidence matrices from microbial communities, including bacteria, archaea, fungi, and algae, and we compare these results to previously published findings from a meta-analysis of almost 100 macroorganism data sets. We show that assemblages of microorganisms demonstrate nonrandom patterns of co-occurrence that are broadly similar to those found in assemblages of macroorganisms. These results suggest that some taxon co-occurrence patterns may be general characteristics of communities of organisms from all domains of life. We also find that co-occurrence in microbial communities does not vary among taxonomic groups or habitat types. However, we find that the degree of co-occurrence does vary among studies that use different methods to survey microbial communities. Finally, we discuss the potential effects of the undersampling of microbial communities on our results, as well as processes that may contribute to nonrandom patterns of co-occurrence in both macrobial and microbial communities such as competition, habitat filtering, historical effects, and neutral processes.     

Predators, parasitoids, and pathogens: a cross-cutting examination of intraguild predation theory

Although the canonical concept of intraguild predation evokes images of predators and prey, several subdisciplines within ecology have developed theory not specifically framed in terms of predation and competition and often using system-specific terminology, yet functionally quite similar. Here, we formulate models combining exploitation and competition in predator-prey, host-parasitoid, and host-pathogen communities to compare dynamics, food web structure, and coexistence criteria for these disparate communities. Although dynamic stability in the coexistence region varies strongly among systems, in all cases coexistence of two consumers on a single resource occurs only if the intraguild prey species is more efficient than the intraguild predator at suppressing the abundance of the basal resource, and if the intraguild predator accrues a sufficient gain from attacking the intraguild prey. In addition, equilibrial abundances of all species in all three formulations respond similarly to increases in productivity of the basal resource. Our understanding of predator-prey and parasitoid-host communities has benefited from explicit examination of intraguild predation (IGP) theory, and we suggest that future research examining pathogen communities, in particular, will benefit substantially from explicit recognition of predictions from IGP theory.     

Quantifying construction and demolition waste: An analytical review

Quantifying construction and demolition (C&D) waste generation is regarded as a prerequisite for the implementation of successful waste management. In literature, various methods have been employed to quantify the C&D waste generation at both regional and project levels. However, an integrated review that systemically describes and analyses all the existing methods has yet to be conducted. To bridge this research gap, an analytical review is conducted. Fifty-seven papers are retrieved based on a set of rigorous procedures. The characteristics of the selected papers are classified according to the following criteria - waste generation activity, estimation level and quantification methodology. Six categories of existing C&D waste quantification methodologies are identified, including site visit method, waste generation rate method, lifetime analysis method, classification system accumulation method, variables modelling method and other particular methods. A critical comparison of the identified methods is given according to their characteristics and implementation constraints. Moreover, a decision tree is proposed for aiding the selection of the most appropriate quantification method in different scenarios. Based on the analytical review, limitations of previous studies and recommendations of potential future research directions are further suggested.     

Driving self-restriction in high-risk conditions: how do older drivers compare to others?

Introduction

Many older drivers self-restrict or avoid driving under high-risk conditions. Little is known about the onset of driving self-restrictions or how widespread self-restrictions are among drivers of all ages.

Methods

The Second Injury Control and Risk Survey (ICARIS-2) was a nationwide cross-sectional, list-assisted random-digit-dial telephone survey from 2001 to 2003. National prevalence estimates and weighted percentages of those reporting driving self-restrictions were calculated. Multivariable logistic regression was used to explore associations between specific self-restrictions and age group, adjusting for other personal characteristics.

Results

More than half of all drivers reported at least one driving self-restriction. The most commonly reported restriction was avoidance of driving in bad weather (47.5%), followed by at night (27.9%) and on highways or high-speed roads (19%). A greater percentage of young adult women (18-24 years) reported self-restricting in bad weather compared to women in other age groups, and the percentage of drivers self-restricting at night, in bad weather, and on highways or high-speed roads increased steeply after age 64. We found that women, those in low income groups, and those who had driven low annual mileage were more likely to self-restrict.

Conclusions

In addition to assessing self-restrictions among older drivers, a new finding from our study is that self-restrictions are also quite prevalent among younger age groups. Driving self-restrictions may be better understood as a spectrum across ages in which drivers’ reasons for restriction change.

Impact on industry

Future research on the ability of driving self-restrictions to reduce actual crash risk and prevent injuries is needed.     

Factors influencing private and public environmental protection behaviors: results from a survey of residents in Shaanxi, China

Currently one of the largest and most rapidly developing countries, China also has some of the world's most severe environmental problems. China will most likely need to use all of the potential major strategies currently available to solve the country's huge environmental challenges, including promoting individual conservation behavior through educational campaigns and encouraging public environmental advocacy. This paper summarized the findings of a survey of 347 residents of Shaanxi province on environmental attitudes and behaviors. The survey found generally high levels of environmental knowledge and high recognition of the seriousness of environmental issues, moderate levels of individual actions supporting environmental resource conservation and low levels of public environmental behaviors, particularly for organized public advocacy. Further analysis indicated that the perceived importance of environmental protection is the most important factor influencing individual environmental resource conservation, but not public advocacy behaviors. Implications for environmental campaigns are discussed.     

Temporal and spatial variation in the δ<Superscript>15</Superscript>N and δ<Superscript>13</Superscript>C values of fish and squid from Alaskan waters

To test the hypothesis that stable isotope ratios from marine organisms vary, the δ¹⁵N and δ¹³C values from fish and squid collected in Alaskan waters were measured across years (1997, 2000, and 2005), seasons, geographic locations, and different size/age classes, and between muscle tissue and whole animals. Temporal, geographic, and ontogenetic differences in stable isotope ratios ranged from 0.5–2.5‰ (δ¹⁵N) to 0.5–2.0‰ (δ¹³C). Twenty-one comparisons of stable isotope values between whole organisms and muscle tissue revealed only four small differences each for δ¹⁵N and δ¹³C, making costly and space prohibitive collection of whole animals unnecessary. The data from this study indicate that significant variations of stable isotope values from animals in marine systems necessitates collection of prey and predator tissues from the same time and place for best interpretation of stable isotope analysis in foraging ecology studies.     

Sustainable urban community development from the grassroots: Challenges and opportunities in a pedestrian street initiative

Abstract

A local sustainable development initiative to establish a temporary pedestrian zone within a Canadian urban community served as a research study into the efficacy of social capital in the development of a network for community action. This community-based initiative used social capital to overcome campaign obstacles and the campaign itself generated new social capital within the neighbourhood through the creation of adaptive networks of participants. The campaign succeeded in creating a part-time pedestrian-only space that serves as an educational example of change for sustainable community development that is replicable in other communities, and provides an example of alternative occupation of community space. Contrary to other literature, little evidence of “core burnout” was found although the network does continue to expend a large amount of effort and time on fundraising. While social capital is a powerful tool for local grassroots action, the availability of a critical source of economic capital may prove vital to the long-term success and sustainability of the network.     

Environmental Racialization: Linking Racialization to the Environment in Canada

Abstract

This paper introduces the concept of environmental racialization to account for how race is socially and spatially organized in large Canadian cities. Drawing on a theoretical analysis of the notion of intentionality as conceived in environmental justice literature, the argument is made that claims of environmental racism must include direct a connection between agent's subjective racist intent and the powerful racist outcomes. In contrast, environmental racialization recognizes that agents’ intentional actions can result in unpurposeful racist outcomes, even if these outcomes are systemic. The case study of the community of Mid-Scarborough in Toronto illustrates the relevance of the concept of environment racialization.     

Urban environmental justice through the camera: understanding the politics of space and the right to the city

Using the lens of Lefebvre's spatial trialectics, we assess the utility of photo-elicited interviewing for environmental justice, recognising that a view to social spatial analysis is essential to engaging with the historical processes of exclusion and discrimination that are crucial to explaining why unequal distributions of environmental injustice are systemic and not random. Drawing on insights from our own photo-elicited interviewing-based work in the neighbourhood called Parkdale in Toronto, we make two main recommendations for future environmental justice work using photo-elicited interviewing. First, researchers must be open to a broader epistemology, one that draws on a more spatially nuanced and temporally evolving knowledge of the full range of environmental influences on communities. Second, in order to arrive at a more robust critical analysis of social space, researchers should complement photo-elicited interviewing with historical research about the relevant communities and include participants from other comparative communities.     

Ten steps toward integrated environmental excellance

Environmental management is moving away from the traditional use of specialists to currect end-of-the-pipe problems and instead is moving back in the process to reduce the production of these waste materials. The author shows how integrating environmental responsiblity all the way down the production line might work in a practical application, including a ten-step formula for putting a total quality environmental program in place.