Anion Assisted Redox Rates Between Cobalt (II) - Cobalt (III) Polypyridyl Complexes in Acetophenone

The effects of ionic strength and various anions on the rate of electron transfer between tris(2,2\u27-dipyridine) cobalt(III) and bis(2,2\u27,2 -tripyridine) cobalt(II) complexes have been examined in acetophenone. The redox rate was found to increase with increasing ionic strength in both the presence and absence of added salts. The reaction was first order with respect to each reactant and second order overall in all cases. The influence of the C104, BF4, and B(C6H5)4 anions on the reaction rate was studied with their order of effectiveness being: C104- \u3e BF4 \u3e\u3e B(C6H5)4. The reverse trend occurs in their ion pairing properties where the large size of the B(C6F5)4 stronger anion exerts a much stronger tendency to form ion pairs with the large reactant cations than either of the C104 and BF4 species. The proposed rate law in the presence of the C104 and BF4 anions was as follows: Rate = Kx[Co(dipy)3/3+][Co(tripy)2X+ where the rate is independent of the anion concentration. An alternate rate law was proposed for the B(C6H5)T4 anion where a greater degree of ion pairing was obtained. In the absence of added salts, the redox rate Is believed to occur by two different reaction pathways. Activation parameters were determined for each salt system as well as in the absence of added salts at µ = 0.0027 M and over a temperature range of 25-41°C. Factors affecting the activation parameters are discussed

Sea turtle nesting in the Ten Thousand Islands of Florida

Loggerhead sea turtles (Caretta caretta) nest in numerous substrate and beach types within the Ten Thousand Islands (TTl) of southwest Florida. Nesting beach selection was analyzed on 12 islands within this archipelago. Numerous physical characteristics were recorded to identify the relatedness of these variables and determine their importance for nesting beach selection in C. caretta. These variables were chosen after evaluating the islands, conducting literature searches and soliciting personal communications. Along transects, data were collected, on the following: height of canopy, beach width, overall slope (beach slope and slope of offshore approach) and sand samples analyzed for pH, percentage of water, percentage of organic content, percentage of carbonate and particle size (8 size classes). Data on ordinal aspect of beaches and beach length were also recorded and included in the analysis. All of the variables were analyzed by tree regression, incorporating the nesting data into the analysis. In the TTl, loggerheads appear to prefer wider beaches (p< 0.001; R2 = 0.56) that inherently have less slope, and secondarily, wider beaches that have low amounts of carbonate (p< O.00 1). In addition, C. caretta favors nest sites within or in close proximity to the supra-littoral vegetation zone of beaches in the TTl (p< 0.001). (86 page document

Can We Manage for Resilience? The Integration of Resilience Thinking into Natural Resource Management in the United States

The concept of resilience is now frequently invoked by natural resource agencies in the US. This reflects growing trends within ecology, conservation biology, and other disciplines acknowledging that social–ecological systems require management approaches recognizing their complexity. In this paper, we examine the concept of resilience and the manner in which some legal and regulatory frameworks governing federal natural resource agencies have difficulty accommodating it. We then use the U.S. Forest Service’s employment of resilience as an illustration of the challenges ahead

Embracing panarchy, building resilience and integrating adaptive management through a rebirth of the National Environmental Policy Act

Environmental law plays a key role in shaping policy for sustainability of socialeecological systems. In particular, the types of legal instruments, institutions, and the response of law to the inherent variability in socialeecological systems are critical. Sustainability likely must occur via the institutions we have in place, combined with alterations in policy and regulation within the context of these institutions. This ecosystem management arrangement can be characterized as a panarchy, with research on sustainability specific to the scale of interest. In this manuscript we examine an opportunity for integrating these concepts through a regulatory rebirth of the National Environmental Policy Act (NEPA). NEPA currently requires federal agencies to take a “hard look” at the environmental consequences of proposed action. The original intent of NEPA, however, was more substantive and its provisions, while currently equilibrium based, may be reconfigured to embrace new understanding of the dynamics of socialeecological systems

Spatiotemporal variability in Swedish lake ecosystems

Studying ecosystem dynamics is critical to monitoring and managing linked systems of humans and nature. Due to the growth of tools and techniques for collecting data, information on the condition of these systems is more widely available. While there are a variety of approaches for mining and assessing data, there is a need for methods to detect latent characteristics in ecosystems linked to temporal and spatial patterns of change. Resiliencebased approaches have been effective at not only identifying environmental change but also providing warning in advance of critical transitions in social-ecological systems (SES). In this study, we examine the usefulness of one such method, Fisher Information (FI) for spatiotemporal analysis. FI is used to assess patterns in data and has been established as an effective tool for capturing complex system dynamics to include regimes and regime shifts. We employed FI to assess the biophysical condition of eighty-five Swedish lakes from 1996–2018. Results showed that FI captured spatiotemporal changes in the Swedish lakes and identified distinct spatial patterns above and below the Limes Norrlandicus, a hard ecotone boundary which separates northern and southern ecoregions in Sweden. Further, it revealed that spatial variance changed approaching this boundary. Our results demonstrate the utility of this resilience-based approach for spatiotemporal and spatial regimes analyses linked to monitoring and managing critical watersheds and waterbodies impacted by accelerating environmental change

Spatiotemporal variability of Swedish lake ecosystems

Studying ecosystem dynamics is critical to monitoring and managing linked systems of humans and nature. Due to the growth of tools and techniques for collecting data, information on the condition of these systems is more widely available. While there are a variety of approaches for mining and assessing data, there is a need for methods to detect latent characteristics in ecosystems linked to temporal and spatial patterns of change. Resiliencebased approaches have been effective at not only identifying environmental change but also providing warning in advance of critical transitions in social-ecological systems (SES). In this study, we examine the usefulness of one such method, Fisher Information (FI) for spatiotemporal analysis. FI is used to assess patterns in data and has been established as an effective tool for capturing complex system dynamics to include regimes and regime shifts. We employed FI to assess the biophysical condition of eighty-five Swedish lakes from 1996–2018. Results showed that FI captured spatiotemporal changes in the Swedish lakes and identified distinct spatial patterns above and below the Limes Norrlandicus, a hard ecotone boundary which separates northern and southern ecoregions in Sweden. Further, it revealed that spatial variance changed approaching this boundary. Our results demonstrate the utility of this resilience-based approach for spatiotemporal and spatial regimes analyses linked to monitoring and managing critical watersheds and waterbodies impacted by accelerating environmental change

Time-series Analysis of Clusters in City Size Distributions

Complex systems, such as urban systems, emerge unpredictably without the influence of central control as a result of adaptive behavior by their component, interacting agents. This paper analyses city size distributions, by decade, from the south-western region of the United States for the years 1890–1990. It determines if the distributions were clustered and documents changes in the pattern of clusters over time. Clusters were determined utilizing a kernel density estimator and cluster analysis. The data were clustered as determined by both methods. The analyses identified 4–7 clusters of cities in each of the decades analysed. Cities cluster into size classes, suggesting variability in growth rates at different scales

Impact of Hurricane Katrina on the Coastal Systems of Southern Louisiana

Natural disasters, such as hurricanes and forest fires, could trigger collapse and reorganization of social-ecological systems. In the face of external perturbations, a resilient system would have capacity to absorb impacts, adapt to change, learn, and if needed, reorganize within the same regime. Within this context, we asked how human and natural systems in Louisiana responded to Hurricane Katrina, and how the natural disaster altered the status of these systems. This paper discusses community resilience to natural hazards and addresses the limitations for assessing disaster resilience. Furthermore, we assessed social and environmental change in New Orleans and southern Louisiana through both a spatial and temporal lens (i.e., pre- and post-Katrina). By analyzing changes in system condition using social, economic and environmental factors, we identified some of the characteristics of the system’s reorganization trajectories. Our results suggest that although the ongoing population recovery may be a sign of revitalization, the city and metropolitan area continue to face socioeconomic inequalities and environmental vulnerability to natural disasters. Further, the spatial distribution of social-ecological condition over time reveals certain levels of change and reorganization after Katrina, but the reorganization did not translate into greater equity. This effort presents an enhanced approach to assessing social-ecological change pre and post disturbance and provides a way forward for characterizing pertinent aspects of disaster resilience