Michael J. Baca

Gene-environment interactions affect long-term depression (LTD) through changes in dopamine receptor affinity in Snap25 deficient mice.

Genes and environmental conditions interact in the development of cognitive capacities and each plays an important role in neuropsychiatric disorders such as attention deficit/hyperactivity disorder (ADHD) and schizophrenia. Multiple studies have indicated that the gene for the SNARE protein SNAP-25 is a candidate susceptibility gene for ADHD, as well as schizophrenia, while maternal smoking is a candidate environmental risk factor for ADHD. We utilized mice heterozygous for a Snap25 null allele and deficient in SNAP-25 expression to model genetic effects in combination with prenatal exposure to nicotine to explore genetic and environmental interactions in synaptic plasticity and behavior. We show that SNAP-25 deficient mice exposed to prenatal nicotine exhibit hyperactivity and deficits in social interaction. Using a high frequency stimulus electrophysiological paradigm for long-term depression (LTD) induction, we examined the roles of dopaminergic D2 receptors (D2Rs) and cannabinoid CB1 receptors (CB1Rs), both critical for LTD induction in the striatum. We found that prenatal exposure to nicotine in Snap25 heterozygote null mice produced a deficit in the D2R-dependent induction of LTD, although CB1R regulation of plasticity was not impaired. We also show that prenatal nicotine exposure altered the affinity and/or receptor coupling of D2Rs, but not the number of these receptors in heterozygote null Snap25 mutants. These results refine the observations made in the coloboma mouse mutant, a proposed mouse model of ADHD, and illustrate how gene×environmental influences can interact to perturb neural functions that regulate behavior.

City of Hoboken Energy Surety Analysis: Preliminary Design Summary

In 2012, Hurricane Sandy devastated much of the U.S. northeast coastal areas. Among those hardest hit was the small community of Hoboken, New Jersey, located on the banks of the Hudson River across from Manhattan. This report describes a city-wide electrical infrastructure design that uses microgrids and other infrastructure to ensure the city retains functionality should such an event occur in the future. The designs ensure that up to 55 critical buildings will retain power during blackout or flooded conditions and include analysis for microgrid architectures, performance parameters, system control, renewable energy integration, and financial opportunities (while grid connected). The results presented here are not binding and are subject to change based on input from the Hoboken stakeholders, the integrator selected to manage and implement the microgrid, or other subject matter experts during the detailed (final) phase of the design effort.

Evaluating the effect of resource constraints on resilience of bulk power system with an electric power restoration model

Although reliability standards for electric power systems are well accepted, methods and metrics are not established for evaluating the effects of large-scale disruptions that exceed N – 1 criteria for bulk power systems. This paper introduces a model for simulating restoration of bulk power systems following such disruptions. The model allows analysts to simulate disruption of a bulk power system by designating system components as damaged or non-functional. The analyst further defines recovery resource availability and restoration priorities. The model then compares resource requirements to constraints to calculate the timeline of repair completion and the dynamic restoration of power across the network. Resilience metrics quantify the impacts and costs of the disruption to the utility. These quantities enable the analyst to evaluate how proposed system improvements affect restoration and resilience of the bulk power system. The paper concludes with an illustrative case study on a simplified seven-bus system.

A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing.

The human brain (volume=1200cm3) consumes 20W and is capable of performing>10%5E16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m%5E3 and 3MW, giving the brain a 10%5E12 advantage in operations/s/W/cm%5E3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

Venetie, Alaska energy assessment.

This report summarizes the Energy Assessment performed for Venetie, Alaska using the principals of an Energy Surety Microgrid (ESM) The report covers a brief overview of the principals of ESM, a site characterization of Venetie, a review of the consequence modeling, some preliminary recommendations, and a basic cost analysis.

Kalaeloa Energy System Redevelopment Options Including Advanced Microgrids.

In June 2016, the Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE) in collaboration with the Renewable Energy Branch for the Hawaii State Energy Office (HSEO), the Hawaii Community Development Authority (HCDA), the United States Navy (Navy), and Sandia National Laboratories (Sandia) established a project to 1) assess the current functionality of the energy infrastructure at the Kalaeloa Community Development District, and 2) evaluate options to use both existing and new distributed and renewable energy generation and storage resources within advanced microgrid frameworks to cost-effectively enhance energy security and reliability for critical stakeholder needs during both short-term and extended electric power outages. This report discusses the results of a stakeholder workshop and associated site visits conducted by Sandia in October 2016 to identify major Kalaeloa stakeholder and tenant energy issues, concerns, and priorities. The report also documents information on the performance and cost benefits of a range of possible energy system improvement options including traditional electric grid upgrade approaches, advanced microgrid upgrades, and combined grid/microgrid improvements. The costs and benefits of the different improvement options are presented, comparing options to see how well they address the energy system reliability, sustainability, and resiliency priorities identified by the Kalaeloa stakeholders.

Induction frequency affects cortico-striatal synaptic plasticity with implications for frequency filtering.

Long-term synaptic depression (LTD) in cortico-striatal circuits is initiated by depolarization of striatal medium spiny neurons through a convergent cortical glutamatergic input. This produces retrograde endocannabinoid signaling to presynaptic cortical terminals and eventually results in long term (>30 min) decreases in glutamate release. These same circuits can also undergo short-term depression (STD) through a less well-defined process in which the magnitude of postsynaptic responses returns to baseline levels within 10 min. Additionally, the cortico-striatal circuit shows characteristics of a GABAA receptor-dependent low-pass filter, which results in significant attenuation of high frequency cortical inputs. The majority of in vitro studies of LTD have used a 100-Hz induction paradigm and it is unclear whether other frequencies, which may also have physiological relevance, have equivalent ability to induce this form of plasticity. Here we have investigated the effectiveness of a range of induction paradigms in producing LTD in cortico-striatal circuits, and demonstrate that some lower frequency paradigms, with perhaps more physiological relevance, are more effective at inducing LTD. We also show that GABAA receptor-dependent frequency filtering in this circuit is altered following the induction of LTD and STD suggesting an important role for synaptic depression in signal processing in these circuits.

A mission resilience assessment methodology for infrastructure disruptions

Resilience has recently emerged as a security priority, but the development of mission resilience analysis techniques for military systems has lagged behind those for other systems. This paper identifies gaps for mission resilience assessment in current vulnerability assessment approaches used at military facilities. Additionally, the paper describes ongoing research to develop a set of mission resilience models that addresses those gaps and could be used to evaluate mission resilience to electric power outages.