OBJECTIVES/GOALS: To develop feasible screening methods for activity of the enzyme Glucose-6-phosphate dehydrogenase (G6PD) with point of care applicability. METHODS/STUDY POPULATION: Current knowledge establishes the relevance of G6PD as a critical therapeutic determinant for effective antimalarial therapy due to the occurrence of mutations that lead to post-treatment severe adverse effects. We present our findings on development of cost effective point-of-care screening methodologies to ascertain G6PD deficiency. RESULTS/ANTICIPATED RESULTS: Using Patient Cohort Explorer and data from the Department of Pathology, we established the prevalence of G6PD deficiency at the University of Mississippi Medical Center, Jackson, MS as high as 11.8% (African-American males in all population, n = 2518). Next, for selection of potential target groups, we set up a protocol for recruitment of volunteers based on ethnic background, parental ethnicity, and medical history. G6PD activity was evaluated using point of care methods [Trinity Biotech test or CareSTART Biosensor], and Gold Standard quantitative spectrophotometric assay (LabCorp). Determinations in >20 subjects have showed comparable concordance. If used with a conservative interpretation of the signal, the Trinity Biotech test showed superior potential for use in the field relative to the CareSTART Biosensor. DISCUSSION/SIGNIFICANCE OF IMPACT: We established the prevalence of G6PD deficiency in our medical center. We have also setup tests for point-of-care assessment of G6PD. Pending evaluation of the relative tests performance, we will be in position to screen individuals and select them for a prospective clinical trial to evaluate the safety of antimalarial agents on scope of G6PD deficiency.

Giant electromagnetic pulses (EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers (e.g. the Extreme Light Infrastructure). We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP, providing an opportunity for comparison with existing charge separation models.

Background: Differences in the level of cognitive compromise between individuals following brain injury are thought to arise from underlying differences in cognitive reserve. The level of cognitive reserve attained by an individual is influenced by both genetic and life experience factors such as educational attainment and occupational history. The Tasmanian Healthy Brain Project (THBP) is a world-first prospective study examining the capacity of university-level education to enhance cognitive reserve in older adults and subsequently reduce age-related cognitive decline and risk for neurodegenerative disease.

Methods: Up to 1,000 adults aged 50–79 years at the time of entry into the study will be recruited to participate in the THBP. All participants will be healthy and free of significant medical, psychological, or psychiatric illness. Of the participant sample, 90% will undertake a minimum of 12 months part-time university-level study as an intervention. The remaining 10% will act as a control reference group. Participants will complete an annual comprehensive assessment of neuropsychological function, medical health, socialization, and personal well-being. Premorbid estimates of past cognitive, education, occupational, and physical function will be used to account for the mediating influence of prior life experience on outcomes. Potential contributing genetic factors will also be explored.

Results: Participant results will be assessed annually. Participants displaying evidence of dementia on the comprehensive neuropsychological assessment will be referred to an independent psycho-geriatrician for screening and diagnosis.

Conclusions: The THBP commenced in 2011 and is expected to run for 10–20 years duration. To date, a total of 383 participants have been recruited into the THBP.

The central serotonergic system has been implicated in the pathophysiology of panic disorder (PD) by evidence of abnormally elevated serotonin-turnover, reduced pre- and post-synaptic 5-HT1A−receptor sensitivity and binding and clinical improvement during administration of agents that enhance serotonergic transmission. Polymorphisms in genes that putatively influence serotonergic neurotransmission increase the vulnerability for developing PD specifically in males. We tested the hypotheses that serotonin transporter (5-HTT) binding is elevated in PD subjects vs. healthy controls in regions where in vivo evidence exists for both elevated 5-HTT and 5-HT1A receptor levels in PD and investigated whether the extent of this difference depends upon gender. Volunteers were out-patients with current PD (n=24) and healthy controls (n=24). The non-displaceable component of 5-HTT binding-potential (BPND) was measured using positron emission tomography and the 5-HTT selective radioligand, [11C]DASB. PD severity was assessed using the PD Severity Scale. The 5-HTT-BPND was increased in males with PD relative to male controls in the anterior cingulate cortex (F=8.96, pFDR=0.01) and midbrain (F=5.09, pFDR=0.03). In contrast, BPND did not differ between females with PD and female controls in any region examined. The finding that 5-HTT-binding is elevated in males but not in females with PD converges with other evidence suggesting that dysfunction within the central serotonergic system exists in PD, and also indicates that such abnormalities are influenced by gender. These findings conceivably may reflect a sexual dimorphism that underlies the greater efficacy of serotonin reuptake inhibitor treatment in females vs. males with PD.

The phenologies and distributions of pea aphid (Acyrthosiphon pisum (Harris)), blue alfalfa aphid (A. kondoi (Shinji)), and spotted alfalfa aphid (Therioaphis maculata (Buckton)) were intensively studied in California alfalfa. The results showed, as expected, that aphid populations across all densities were aggregated; but that ladybird beetle (Hippodamia convergens (G.-M.)) predation increased the degree of aggregation. The distribution parameters of the aphids were estimated using methods developed by Iwao and Kuno (1971).

Population models for the Egyptian alfalfa weevil and alfalfa are reported, which compared favorably with field data. A mechanism for coupling the plant–herbivore trophic levels is suggested.

Frazer and Gilbert (1976) described the predation of pea aphids, Acyrthosiphon pisum (Harris), by adult coccinellids. They developed a formula to predict the predation rate as a function of temperature, predator density, and prey age-distribution and density. Gutierrez et al. (1979) extended the formula to describe several predators sharing the same prey. The following papers develop the study to cover the complete predator-prey relationship, including the dynamics of both predators and prey.

The behavior of larval stages of the green lace wing, Chrysopa carnea Stephens, and of the ladybird beetle Hippodamia convergens G.-M. were studied in the laboratory. With increasing hunger level, only first instar H. convergens larvae spent more time searching in the upper part of alfalfa stems, where both prey aphids, Acyrthosiphon pisum (Harris) and Acyrthosiphon kondoi (Shinji), are found. All larval instars tested except first instar C. carnea visited more stems per unit time with increasing hunger level. The weight gain, the developmental time, and the mortality of all larvae were adversely influenced at low food levels, but differently for each predator size and species. C. carnea larvae had higher rates of fat body utilization and weight gain than coccinellid larvae.

The field population dynamics of pea aphid (Acyrthosiphon pisum) and blue alfalfa aphid (A. kondoi) in alfalfa (Medicago sativa), as influenced by weather, competitors (Egyptian alfalfa weevil = EAW, Hypera brunneipennis), predation from coccinellids (Hippodamia convergens) and harvesting practices, are examined with a stochastic multitrophic level simulation model. The model incorporates a demand-driven functional-response model to estimate prey consumption, and a metabolic pool model to determine the rates and priorities of food allocation to respiration, growth, reproduction, and egestion.

The model results compare favorably with field data, and are used to examine the effects of removal of each of the above factors on the dynamics of the aphids. The model shows that the observed density of EAW did not affect the aphid dynamics, but did reduce the standing crop of alfalfa. The predator H. convergens had a significant effect on the population dynamics of the aphids and the plant. Harvesting greatly affected the aphid population dynamics, as well as the dynamics of plant growth and reserve accumulation. However, high temperatures mediated through species-specific respiration costs and possibly a fungal pathogen were responsible for the observed dominance of blue aphid populations in the cool parts of the year and pea aphid populations during warmer parts of the year.

A simple age-specific energetics (calories or biomass) model for the growth and development, reproduction, respiration, ageing, and intrinsic survivorship as a function of temperature and per capita energy availability for pea aphid (Acyrthosiphon pisum (Harris)) is reported. The ratio of energy supply–demand is used to scale all of the rates in the model. The maximum demand for energy based upon current state values is used to drive the Frazer–Gilbert functional response model (i.e. food acquisition), which is a component of the metabolic pool model used to assimilate energy to growth, reproduction, respiration, and egestion. The extensive data sets on pea aphid energetics published by Randolph et al. (1975) were used to develop the model. As the model estimates reproduction (Mx) and survivorship (Lx) values, extensive published age-specific life-data sets on pea aphids are used to test it. The results suggest:

(1) the lower thermal threshold for development is raised and the upper threshold is lowered as food resources are decreased

(2) the temperature-dependent rate of development is slowed with decreasing energy resources

(3) the size of individuals and reproduction become smaller as temperature approaches the upper and lower thermal thresholds.A simple model for multitrophic level interactions incorporating the acquisition and assimilation functions is presented.