Guiding decisions on the future of dams: A GIS database characterizing ecological and social considerations of Dam decisions.

In the United States and elsewhere, there are a growing number of dams which have exceeded their design life and will need to be repaired or removed in the coming decades. Most of these dams no longer serve their original purpose and removal can provide ecological benefits and eliminate future maintenance costs and hazards. However, many decision-makers have been ill-prepared by community resistance to proposals to remove dams. Given the number of dam removal initiatives that have failed or been delayed due to community resistance, both ecological and social attributes of dams need to be better mapped and conveyed in understandable ways. The goal of this study was to support future decisions regarding dams by 1) developing a set of metrics to assess the social and ecological dimensions of dams, and 2) using these metrics to develop a GIS database, for the 1000+ dams in the Narragansett Bay/Rhode Island area of southern New England. The database characterizes the ecological benefits of dam removal or modification, in terms of fish passage, and the social dimensions that may need to be considered when engaging a community in discussions about the future of a dam. Our emphasis was on small-head dams (i.e. <5 m tall) which comprise most dams in the study area. We created social value metrics that used GIS data to assess dams and their impoundments for potential benefits to waterfront properties, history, sense-of-place, and recreation. We modeled our ecological metrics and ranking system after the Nature Conservancy's Northeast Aquatic Connectivity study which considered factors relating to river connectivity and watershed quality. We evaluated our social and ecological metrics using case studies of dams in the study area that had been previously removed or modified. We assumed that both sets of dams were ecologically important, but the modified dams had higher social value that prohibited their removal. Dams that had been removed or modified were both ranked as high priority in terms of value for fish passage, particularly for diadromous fish. Dams that were modified to include fish passage had substantially larger impoundments, more waterfront properties, and more features associated with recreational or cultural value (e.g. boating opportunity, visibility, etc.). Our social metrics were consistent with expectations based on the limited case studies (7 removals, 19 modifications) available in the study area. We made the dam assessment metrics readily accessible to stakeholders through an interactive ArcGIS Online web map.

Genetic removal of synaptic Zn2+ impairs cognition, alters neurotrophic signaling and induces neuronal hyperactivity.

Vesicular Zn2+ (zinc) is released at synapses and has been demonstrated to modulate neuronal responses. However, mechanisms through which dysregulation of zinc homeostasis may potentiate neuronal dysfunction and neurodegeneration are not well-understood. We previously reported that accumulation of soluble amyloid beta oligomers (AßO) at synapses correlates with synaptic loss and that AßO localization at synapses is regulated by synaptic activity and enhanced by the release of vesicular Zn2+ in the hippocampus, a brain region that deteriorates early in Alzheimer's disease (AD). Significantly, drugs regulating zinc homeostasis inhibit AßO accumulation and improve cognition in mouse models of AD. We used both sexes of a transgenic mouse model lacking synaptic Zn2+ (ZnT3KO) that develops AD-like cognitive impairment and neurodegeneration to study the effects of disruption of Zn2+ modulation of neurotransmission in cognition, protein expression and activation, and neuronal excitability. Here we report that the genetic removal of synaptic Zn2+ results in progressive impairment of hippocampal-dependent memory, reduces activity-dependent increase in Erk phosphorylation and BDNF mRNA, alters regulation of Erk activation by NMDAR subunits, increases neuronal spiking, and induces biochemical and morphological alterations consistent with increasing epileptiform activity and neurodegeneration as ZnT3KO mice age. Our study shows that disruption of synaptic Zn2+ triggers neurodegenerative processes and is a potential pathway through which AßO trigger altered expression of neurotrophic proteins, along with reduced hippocampal synaptic density and degenerating neurons, neuronal spiking activity, and cognitive impairment and supports efforts to develop therapeutics to preserve synaptic zinc homeostasis in the brain as potential treatments for AD.

Language effects on bargaining.

Language is critical to coordination in groups. Though, how language affects coordination in groups is not well understood. We prime distributive and integrative language in a bargaining experiment to better understand the links between group outcomes and communication. We accomplish this by priming interests or positions language in randomized groups. We find that priming positions as opposed to interests language leads to agreements where controllers, subjects with unilateral authority over the group outcome, receive a larger share of the benefits but where the total benefits to the group are unaffected. In contrast to common justifications for the use of integrative language in bargaining, our experimental approach revealed no significant differences between priming interests and positions language in regards to increasing joint outcomes for the groups. Across treatments, we find subjects that use gain frames and make reference to visuals aids during bargaining experience larger gains for the group, while loss frames and pro-self language experience larger gains for the individual through side payments. This finding suggests a bargainer's dilemma: whether to employ language that claims a larger share of group's assets or employ language to increase joint gains.

A multiscale approach to balance trade-offs among dam infrastructure, river restoration, and cost.

Aging infrastructure and growing interests in river restoration have led to a substantial rise in dam removals in the United States. However, the decision to remove a dam involves many complex trade-offs. The benefits of dam removal for hazard reduction and ecological restoration are potentially offset by the loss of hydroelectricity production, water supply, and other important services. We use a multiobjective approach to examine a wide array of trade-offs and synergies involved with strategic dam removal at three spatial scales in New England. We find that increasing the scale of decision-making improves the efficiency of trade-offs among ecosystem services, river safety, and economic costs resulting from dam removal, but this may lead to heterogeneous and less equitable local-scale outcomes. Our model may help facilitate multilateral funding, policy, and stakeholder agreements by analyzing the trade-offs of coordinated dam decisions, including net benefit alternatives to dam removal, at scales that satisfy these agreements.

Low Cost Electrode Assembly for EEG Recordings in Mice.

Wireless electroencephalography (EEG) of small animal subjects typically utilizes miniaturized EEG devices which require a robust recording and electrode assembly that remains in place while also being well-tolerated by the animal so as not to impair the ability of the animal to perform normal living activities or experimental tasks. We developed simple and fast electrode assembly and method of electrode implantation using electrode wires and wire-wrap technology that provides both higher survival and success rates in obtaining recordings from the electrodes than methods using screws as electrodes. The new wire method results in a 51% improvement in the number of electrodes that successfully record EEG signal. Also, the electrode assembly remains affixed and provides EEG signal for at least a month after implantation. Screws often serve as recording electrodes, which require either drilling holes into the skull to insert screws or affixing screws to the surface of the skull with adhesive. Drilling holes large enough to insert screws can be invasive and damaging to brain tissue, using adhesives may interfere with conductance and result in a poor signal, and soldering screws to wire leads results in fragile connections. The methods presented in this article provide a robust implant that is minimally invasive and has a significantly higher success rate of electrode implantation. In addition, the implant remains affixed and produces good recordings for over a month, while using economical, easily obtained materials and skills readily available in most animal research laboratories.

Disruption of zinc neuromodulation by Aß oligomers: therapeutic implications.

So far, therapeutics focusing on reducing levels of amyloid beta for treatment of Alzheimer's disease have not been successful in completing clinical trials to come to market, suggesting the need of a wider perspective and the consideration of novel targets of intervention to slow or halt the progression of this disease. One such target is soluble amyloid beta in oligomeric forms, which have been demonstrated to bind with high affinity to zinc released during synaptic activity. This review considers the interaction of AßO and zinc and the role of zinc in neurotransmission along with possible neurotoxic effects of this interaction. Finally, it also discusses recent experimental data in animal models that have translated into potential treatments for AD based on the modulation of hyperexcitability and zinc homeostasis.