Urban landscape networks: an ecological planning framework

This paper presents a framework for the planning of urban landscape networks in an attempt to have nature areas integrated into traditional urban land-use planning. The biophysical and socio-economic benefits of such a network are discussed to provide justification for this incorporation. A framework is described, building upon ecological planning processes and incorporating theory and methodology from landscape ecology. The framework includes an assessment of natural and cultural resources, formulating the spatial structure of the network and examination of network components. Implementation strategies are discussed within the context of traditional urban land-use planning practice.     

Tenure Choice and Labour Market Outcomes

In a series of papers Andrew Oswald has suggested that since home owners are relatively less mobile across geographic locations than renters, regional home ownership rates are positively correlated with regional unemployment rates. This paper examines this hypothesis at the individual level. Search theory suggests that when a subset of the population is less mobile than others, this less mobile group (that is, owners) will have lower probability of employment, longer spells of unemployment and lower wages than more mobile renters. These hypotheses on inferior labour market outcomes for owners were tested using US Current Population Survey data as well as data from the Panel Survey of Income Dynamics. The empirical model suggests that these hypotheses are not supported by any of the tests. Home owners, conditionally or unconditionally, have better labour market outcomes than renters.     

Runoff of pharmaceuticals and personal care products following application of biosolids to an agricultural field

Municipal biosolids are a source of nutrients for crop production. Beneficial Management Practices (BMPs) can be used to minimize the risk of contamination of adjacent water resources with chemical or microbial agents that are of public or environmental health concern. In this field study, we applied biosolids slurry at a commercial rate using either subsurface injection or broadcast application followed by incorporation. Precipitation was simulated at 1, 3, 7, 22, 36 and 266 days post-application on 2 m² microplots to evaluate surface runoff of 9 model pharmaceuticals and personal care products (PPCPs), atenolol, carbamazepine, cotinine, gemfibrozil, naproxen, ibuprofen, acetaminophen, sulfamethoxazole and triclosan. In runoff from the injected plots, concentrations of the model PPCPs were generally below the limits of quantitation. In contrast, in the broadcast application treatment, the concentrations of atenolol, carbamazepine, cotinine, gemfibrozil, naproxen, sulfamethoxazole and triclosan on the day following application ranged from 70-1477 ng L^− 1 in runoff and generally declined thereafter with first order kinetics. The total mass of PPCPs mobilized in surface runoff per m² of the field ranged from 0.63 µg for atenolol to 21.1 µg for ibuprofen. For ibuprofen and acetaminophen, concentrations in runoff first decreased and then increased, suggesting that these drugs were initially chemically or physically sequestered in the biosolids slurry, and subsequently released in the soil. Carbamazepine and triclosan were detected at low concentrations in a runoff event 266 days after broadcast application. Overall, this study showed that injection of biosolids slurry below the soil surface could effectively eliminate surface runoff of PPCPs.     

Applications of dynamic programming in survey engineering

Recent research has shown that probabilistic and non-probabilistic dynamic programming techniques can be applied beneficially in the solution of optimal design and management problems in surveying. The survey design system is presented. A non-probabilistic dynamic programming solution of a second order, one dimensional optimal survey design problem is outlined and some applications of Bayesian dynamic programming to survey logistics and management problems are demonstrated. A useful 'technology transfer' technique is included to illustrate one method of introducing systems theory and operations research to survey engineering.     

Influence of some environmental substances on atrazine adsorption in Baiyangdian lake area soil

Recent reports have attempted to show that fluoridating potable water is linked to increased levels of lead(II) in the blood. We examine these claims in light of the established science and critically evaluate their significance. The completeness of hexafluoro‐silicate hydrolysis is of paramount importance in ensuring that total water quality is maintained. The possible impacts of such complexes as Pb^II—F—SiF₅ or PbF_x ^(2‐x) are discussed as are the contributions of fluoridation byproducts to total acid content. We calculate the fractional distribution of aqueous species based on known chemical equilibria and show the species concentrations for several different model tap waters. We discuss and quantitatively show the effects of other complexing anions, such as carbonate or hydroxide. Overall, we conclude that no credible evidence exists to show that water fluoridation has any quantitatable effects on the solubility, bioavailability, bio‐accumulation, or reactivity of lead(0) or lead(II) compounds. The governing factors are the concentrations of a number of other species, such as (bi)carbonate, hydroxide, or chloride, whose effects far exceed those of fluoride or fluorosilicates under drinking water conditions. Lastly, we consider some previous epidemiological studies of lead(II) exposure and how recent papers fare methodologically.     

The Effect of Mandated Planning on Plan Quality

Problem: What is a “good plan”? Among their key goals, plans aim to communicate, influence and engage. Persuasiveness (the ability to engage and motivate) is, therefore, an essential plan quality. Unfortunately, all too many comprehensive plans lack this important quality. In addition, state planning mandates intended to strengthen planning can instead worsen this shortcoming.

Purpose: To develop a methodology to measure and compare the communicative and persuasive qualities of plans in states with and without planning mandates.

Methods: A specially designed protocol was developed to measure the communicative and persuasive qualities of comprehensive plans. Plans of 20 municipalities in states with planning mandates were compared with those of 20 municipalities in states without planning mandates. Statistical analyses of the results were conducted using the Wilcoxon–Mann–Whitney (U) test and simple t tests.

Results and conclusions: Requiring local governments to prepare plans did not result in better plans—at least as measured by a protocol tailored specifically to assess the persuasiveness and communicative quality of plans. Plans prepared in mandate states were much more rigid and standardized than those prepared in nonmandate states. Nonmandated plans also scored much higher in terms of their narrative and storytelling qualities than mandated plans. Private consultant involvement in plan making significantly increased the communicative and persuasive qualities of plans.

Takeaway for practice: Plans in all 40 municipalities fell far short of the ideal communicative and persuasive qualities set forth in the protocol. The deficiency was greatest in states with planning mandates. The involvement of private consultants had a positive impact on plan quality, while the provision of state funding for planning did not.

Research support: None.     

Comparative study of the temporal evolution of atmospheric lead deposition in Scotland and eastern Canada using blanket peat bogs

The temporal evolution of atmospheric lead deposition and its possible sources were assessed in eastern Canada and in western Scotland, using blanket peat bogs as geochemical archives. Short cores were taken from two remote sites located close to the sea. Significant lead enrichments in the upper layers at both sites reflect the increasing emission of lead into the atmosphere due to anthropogenic activities during the last century. At the Scottish site, a region under aeolian influence from Europe, anthropogenic derived lead could be recognized by the distinctive unradiogenic composition (206Pb/207Pb ratios down to approximately 1.115), being clearly different from the pre-industrial values (206Pb/207Pb approximately 1.166). In contrast, the lead pollution in eastern Canada (influenced by North American sources) is identified by a more radiogenic lead isotope composition (206Pb/207Pb ratios up to approximately 1.199) compared to preindustrial values (206Pb/207Pb approximately 1.161). Emission inventories and isotope characteristics suggest that industrial (coal burning, mining) and traffic (leaded gasoline) outputs are the most likely sources during the first and the second half of the 20th century, respectively, in both, western Scotland and eastern Canada alike. The Scottish record is in line with previous studies of past atmospheric lead deposition. However, the Canadian deposit suggests that the wind derived, pre-industrial lead, is less radiogenic as previously implied using sediment archives. These results are thus the first to report pre-industrial lead isotope ratios and concentrations of atmospheric derived aerosols in North America.     

The Effects of CoCl2 on HIF-1α Protein under Experimental Conditions of Autoprogressive Hypoxia Using Mouse Models

It is well known that cobalt chloride (CoCl₂) can enhance the stability of hypoxia-inducible factor (HIF)-1α. The aim of this study is to detect the effect of CoCl₂ on the hypoxia tolerance of mice which were repeatedly exposed to autoprogressive hypoxia. Balb/c mice were randomly divided into groups of chemical pretreatment and normal saline (NS), respectively injected with CoCl₂ and NS 3 h before exposure to hypoxia for 0 run (H0), 1 run (H1), and 4 runs (H4). Western Blot, electrophoretic mobility shift assay (EMSA), extracellular recordings population spikes in area cornus ammonis I (CA 1) of mouse hippocampal slices and real-time were used in this study. Our results demonstrated that the tolerance of mice to hypoxia, the changes of HIF-1α protein level and HIF-1 DNA binding activity in mice hippocampus, the mRNA level of erythropoietin (EPO) and vascular endothelial growth factor (VEGF), and the disappearance time of population spikes of hippocampal slices were substantially different between the control group and the CoCl₂ group. Over-induction of HIF-1α by pretreatment with CoCl₂ before hypoxia did not increase the hypoxia tolerance.