Effects of air pollutants on the growth and antioxidative system of Norway spruce exposed in open-top chambers

Grafted Norway spruce trees were subjected to exposure beginning in April 1988, to one of four different air treatments in open-top chambers: Charcoal filtered air (CF), non-filtered air (NF), non-filtered air with the addition of O(3) during summer (NFO), and SO(2) plus NO(2) during winter (NFOSN). CF trees were considered as the reference group. No effects on growth parameters were observed. Samples of the two youngest needle year classes were taken late in November 1989 for enzyme determinations. The activity of ascorbic acid peroxidase (A-POD) increased the same level in all treatments, and activities of catalase and dehydroascorbic acid reductase (DHA-R) increased only in NF and NFO treatments. A higher level of activity in the NFOSN treatment was observed only for glucose-6-phosphate-dehydrogenase (Glc-6-P-DH) and non-specific peroxidase (POD). Isoelectric focusing of POD showed a changed pattern in the NFOSN treatment. Neither activity nor isoelectric focusing of superoxidase dismutase (SOD) was changed in any of the treatments.     

Statistical inference on patch-specific survival and movement rates from marked animals

Empirical estimates of patch-specific survival and movement rates are needed to parametrize spatially explicit population models, and for inference on the effects of habitat quality and fragmentation on populations. Data from radio-marked animals, in which both the fates and habitat locations of animals are known over time, can be used in conjunction with continuous-time proportional hazards models to obtain inferences on survival rates. Discrete-time conditional logistic models may provide inference on both survival and movement rates. We use Monte Carlo simulation to investigate accuracy of estimates of survival from both approaches, and movement rates from conditional logistic regression, for two habitats. Bias was low (relative bias < 0.04) and interval coverage accurate (close to the nominal 0.95) for estimates of habitat effect on survival based on proportional hazards. Bias was high ( relative bias 0.60) and interval coverage poor ( = 0.26 vs. nominal 0.95) for estimates of habitat effect based on conditional logistic regression; bias was especially influenced by heterogeneity in survival and the shape of the hazard function, whereas both bias and coverage were affected by ‘memory’ effects in movement patterns. Bias estimates of movement rate was low ( relative bias < 0.05), but interval coverage was poor ( = 0.48–0.80), possibly as a result of poor performance of a Taylor series estimate of variance. An example is provided from a radio-telemetry study of 47 wintering American woodcock (Scolopax minor), illustrating practical difficulties in field studies to parametrize these models. We also discuss extensions of continuous-time models to explicitly include a movement process, and further examine tradeoffs between continuous and discrete models.     

Evaluation of the Impacts of Dock Structures and Land Use on Tidal Creek Ecosystems in South Carolina Estuarine Environments

Tidal creeks and their associated salt marshes are the primary link between uplands and estuaries in the southeastern region. They are also critical nursery and feeding grounds. In addition, the uplands surrounding creeks are preferred sites for homebuilding because of their natural beauty and the ability to access the estuary from a personal dock structure. The objective of this study was to evaluate the cumulative impacts of docks on tidal creek nursery habitats for both small and large tidal creeks. The number of docks was associated with the amount of impervious cover in both small and large creeks. The presence of docks had little measurable effect on sediment metal concentrations at the scale of small and large creeks. In small and large creeks, sediment polycyclic aromatic hydrocarbon (PAH) concentrations were related to the human activity in the upland that includes the presence of docks at the scale of small and large creeks. Some impacts on the benthic community were associated with docks and human activity in small creeks but not in large creeks. Suburban development may reduce fish and crustacean abundances, but the dock may potentially mediate the development effect. Individually, the harm to the marine environment resulting from dock shading, chrominated copper arsenate leachates, and PAH contamination was small at the scale of tidal creeks. However, impacts from dock structures could not be separated from anthropogenic watershed-scale effects. These results demonstrate that suburban development with its accompanying dock construction does represent a major source of environmental degradation to tidal creeks and associated salt marsh habitats.     

Social support and newcomer adjustment in organizations: Attachment theory at work?

Social support has been suggested as important for newcomer adjustment to an organization. The present paper reports a longitudinal study of 91 newcomers to three separate organizations. The effects of availability and helpfulness of 10 sources of social support on newcomers reports of psychological distress, satisfaction, intention to leave, and their supervisors assessment of their performance rating (N of supervisors = 41; n of ratings = 91) were examined. The availability of support activities such as offsite training sessions and business trips were found to be associated with decreased psychological symptoms. Helpfulness of various relationship supports were associated with positive adjustment. These results are discussed within the context of attachment theory and our knowledge of social support in work settings.     

Presenting Triple-Wins? Assessing Projects That Deliver Adaptation,Mitigation and Development Co-benefits in Rural Sub-Saharan Africa

The concept of climate compatible development (CCD) is increasingly employed by donors and policy makers seeking ‘triple-wins’ for development, adaptation and mitigation. While CCD rhetoric is becoming more widespread, analyses drawing on empirical cases that present triple-wins are sorely lacking. We address this knowledge gap. Drawing on examples in rural sub-Saharan Africa, we provide the first glimpse into how projects that demonstrate triple-win potential are framed and presented within the scientific literature. We identify that development projects are still commonly evaluated in terms of adaptation or mitigation benefits. Few are framed according to their benefits across all three dimensions. Consequently, where triple-wins are occurring, they are likely to be under-reported. This has important implications, which underestimates the co-benefits that projects can deliver. A more robust academic evidence base for the delivery of triple-wins is necessary to encourage continued donor investment in activities offering the potential to deliver CCD.     

Chemical mass balance model with fractionation for apportioning PM2.5: a test case for Los Angeles traffic sources

Chemical mass balance receptor models (CMBs) use measured pollutant concentrations, along with source information, to apportion the contributions of primary sources to the measured concentrations. CMBs can be used to evaluate the accuracy of the emission inventories that underlie State Implementation Plan (SIP) modeling, by providing an allocation of emissions to individual source categories. CMBs, however, traditionally have not accounted for the chemical reaction and differential deposition or fractionation that occur between the source and receptor. This means that they have historically had severe limitations in apportioning secondary particulate matter (PM), which is an especially important component of fine PM (PM2.5). Stafford and Liljestrand developed a method to account for fractionation in CMBs using depletion factors based on a solution of the steady-state advection-dispersion equation, including gravitational settling, dry deposition, and first-order chemical reaction.     

Shelter, housing and recovery: a comparison of u.s. Disasters

In this paper we examine the issues associated with the temporary sheltering and housing of victims after natural disasters in the United States. Specific topics addressed include differential access to shelter and housing aid according to social class, ethnicity and related demographic factors; the relationship between post-disaster shelter and housing and long-term recovery; the role of social support networks in the sheltering of victims; and the implications of the research for the provision of shelter and housing aid after disasters.