Formula SAE Intake System

The Formula SAE Intake System is intended to optimize the airflow into a restricted 600cc engine. The intake system is designed, fabricated, and installed in accordance with the FSAE rule book with a focus on maximizing the vehicle’s acceleration. It is directly responsible for determining the drivability of the car and how much horsepower the flow restricted engine produces. Design of the intake was conceptualized based on researching a number of factors including venturi diffusion angles, plenum volumes, and runner lengths. Initial tests were performed utilizing computational fluid dynamics for a total of 367 flow simulations and 261 running hours on various intake components in SolidWorks Flow Simulation 2016. From the beginning, it was known that the intake needed to possess certain contours that would be very difficult to create with sheet metal. It was for this reason that a composite construction was pursued for the plenum of the intake manifold, utilizing fused deposition modeling to form the mold. Flow testing and dynamometer testing will be utilized to verify the effectiveness of the design. In the end, the intake system will provide peak performance in the flow restricted system. The increased brake horsepower and improved vehicle drivability will provide a competitive advantage on any race course.https://scholarscompass.vcu.edu/capstone/1198/thumbnail.jp

Digging Deeper into Egocentric Gaze Prediction

This paper digs deeper into factors that influence egocentric gaze. Instead of training deep models for this purpose in a blind manner, we propose to inspect factors that contribute to gaze guidance during daily tasks. Bottom-up saliency and optical flow are assessed versus strong spatial prior baselines. Task-specific cues such as vanishing point, manipulation point, and hand regions are analyzed as representatives of top-down information. We also look into the contribution of these factors by investigating a simple recurrent neural model for ego-centric gaze prediction. First, deep features are extracted for all input video frames. Then, a gated recurrent unit is employed to integrate information over time and to predict the next fixation. We also propose an integrated model that combines the recurrent model with several top-down and bottom-up cues. Extensive experiments over multiple datasets reveal that (1) spatial biases are strong in egocentric videos, (2) bottom-up saliency models perform poorly in predicting gaze and underperform spatial biases, (3) deep features perform better compared to traditional features, (4) as opposed to hand regions, the manipulation point is a strong influential cue for gaze prediction, (5) combining the proposed recurrent model with bottom-up cues, vanishing points and, in particular, manipulation point results in the best gaze prediction accuracy over egocentric videos, (6) the knowledge transfer works best for cases where the tasks or sequences are similar, and (7) task and activity recognition can benefit from gaze prediction. Our findings suggest that (1) there should be more emphasis on hand-object interaction and (2) the egocentric vision community should consider larger datasets including diverse stimuli and more subjects.Comment: presented at WACV 201

Ro 15-4513 Antagonizes Alcohol-Induced Sedation in Mice Through aß¿2-type GABA(A) Receptors

Peer reviewedPublisher PD

Normal extinction and reinstatement of morphine-induced conditioned place preference in the GluA1-KO mouse line

Extinction and reinstatement of morphine-induced conditioned place preference were studied in glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-receptor GluA1 subunit-deficient mice (global GluA1-KO mice). In line with previous findings, both acquisition and expression of conditioned place preference to morphine (20 mg/kg, subcutaneously) were fully functional in GluA1 KO mice compared with wild-type littermate controls (GluA1-WT), thus enabling the study of extinction. With a 10-session extinction paradigm, the GluA1 KO mice showed complete extinction similar to that of the GluA1-WT mice. Morphine-induced reinstatement (10 mg/kg, subcutaneously) was detected in both mouse lines. GluA1 KO mice moved more during all the phases of the experiment, including the place conditioning trials, extinction sessions, and place preference tests. The results suggest that the GluA1 subunit may be dispensable or prone to compensation at the neural circuitries delineating extinction and reinstatement. The GluA1 KO mice show altered long-term between-session habituation, which extends longer than previously anticipated.Peer reviewe

The Metallicity of the HD 98800 System

Pre-main sequence (PMS) binaries and multiples enable critical tests of stellar models if masses, metallicities, and luminosities of the component stars are known. We have analyzed high-resolution, high signal-to-noise echelle spectra of the quadruple-star system HD 98800 and using spectrum synthesis, computed fits to the composite spectrum for a full range of plausible stellar parameters for the components. We consistently find that sub-solar metallicity yields fits with lower $\chi^2$ values, with an overall best-fit of $[M/H] = -0.20\pm0.10$. This metallicity appears to be consistent with PMS evolutionary tracks for the measured masses and luminosities of the components of HD 98800 but additional constraints on the system and modelling are needed.Comment: 6 pages, 3 figures, 5 tables. Online-only material: color figure. Accepted in Ap

A trade-off between current and future sex allocation revealed by maternal energy budget in a small mammal

Sex-allocation theories generally assume differential fitness costs of raising sons and daughters. Yet, experimental confirmation of such costs is scarce and potential mechanisms are rarely addressed. While the most universal measure of physiological costs is energy expenditure, only one study has related the maternal energy budget to experimentally controlled offspring sex. Here, we experimentally test this in the bank vole (Myodes glareolus) by simultaneously manipulating the litter's size and sex ratio immediately after birth. Two weeks after manipulation, when mothers were at the peak of lactation and were pregnant with concurrent litters, we assessed their energy budget. We found that maternal food consumption and daily energy expenditure increased with the size of the litters being lactated. Importantly, the effects of offspring sex on energy budget depended on the characteristics of the simultaneously gestating litters. Specifically, the mothers nursing all-male litters and concurrently pregnant with male-biased litters had the highest energy expenditure. These had consequences for the next generation, as size of female offspring from the concurrent pregnancy of these mothers was compromised. Our study attests a higher cost of sons, consequently leading to a lower investment in them, and reveals the significance of offspring sex in moulding the trade-off between current and future maternal investment

Multiple actions of fenamates and other nonsteroidal anti-inflammatory drugs on GABA(A) receptors

The nonsteroidal anti-inflammatory drug (NSAID) niflumic acid, a fenamate in structure, has many molecular targets, one of them being specific subtypes of the main inhibitory ligand-gated anion channel, the GABA(A) receptor. Here, we report on the effects of other fenamates and other classes of NSAIDs on brain picrotoxinin-sensitive GABA A receptors, using an autoradiographic assay with [S-35]TBPS as a ligand on mouse brain sections. We found that the other fenamates studied (flufenamic acid, meclofenamic acid, mefenamic acid and tolfenamic acid) affected the autoradiographic signal at low micromolar concentrations in a facilitatory-like allosteric fashion, i.e., without having affinity to the [S-35]TBPS binding site. Unlike niflumic acid that shows clear preference for inhibiting cerebellar granule cell layer GABA(A) receptors, the other fenamates showed little brain regional selectivity, indicating that their actions are not receptor-subtype selective. Of the non-fenamate NSAIDs studied at 100 mu M concentration, diclofenac induced the greatest inhibition of the binding, which is not surprising as it has close structural similarity with the potent fenamate meclofenamic acid. Using two-electrode voltage-clamp assays on Xenopus oocytes, the effect of niflumic acid was found to be dependent on the beta subunit variant and the presence of gamma 2 subunit in rat recombinant alpha 1 beta and alpha 1 beta gamma 2 GABA(A) receptors, with the beta 1 allowing the niflumic acid inhibition and beta 3 the stimulation of the receptor-mediated currents. In summary, the fenamate NSAID5 constitute an interesting class of compounds that could be used for development of potent GABA(A) receptor allosteric agonists with other targets to moderate inflammation, pain and associated anxiety/depression.Peer reviewe

Mice Lacking GABA(A) Receptor delta Subunit Have Altered Pharmaco-EEG Responses to Multiple Drugs

In the brain, extrasynaptically expressed ionotropic, delta subunit-containing gamma-aminobutyric acid A-type receptors (delta-GABA(A)Rs) have been implicated in drug effects at both neuronal and behavioral levels. These alterations are supposed to be caused via drug-induced modulation of receptor ionophores affecting chloride ion-mediated inhibitory tonic currents. Often, a transgenic mouse model genetically lacking the delta-GABA(A)Rs (delta-KO) has been used to study the roles of delta-GABA(A)Rs in brain functions, because a specific antagonist of the delta-GABA(A)Rs is still lacking. We have previously observed with these delta-KO mice that activation of delta-GABA(A)Rs is needed for morphine-induced conditioning of place preference, and others have suggested that delta-GABA(A)Rs act as targets selectively for low doses of ethanol. Furthermore, activation of these receptors via drug-mediated agonism induces a robust increase in the slow-wave frequency bands of electroencephalography (EEG). Here, we tested delta-KO mice (compared to littermate wild-type controls) for the pharmaco-EEG responses of a broad spectrum of pharmacologically different drug classes, including alcohol, opioids, stimulants, and psychedelics. Gaboxadol (THIP), a known superagonist of delta-GABA(A)Rs, was included as the positive control, and as expected, delta-KO mice produced a blunted pharmaco-EEG response to 6 mg/kg THIP. Pharmaco-EEGs showed notable differences between treatments but also differences between delta-KO mice and their wild-type littermates. Interestingly mephedrone (4-MMC, 5 mg/kg), an amphetamine-like stimulant, had reduced effects in the delta-KO mice. The responses to ethanol (1 g/kg), LSD (0.2 mg/kg), and morphine (20 mg/kg) were similar in delta-KO and wild-type mice. Since stimulants are not known to act on delta-GABA(A)Rs, our findings on pharmaco-EEG effects of 4-MMC suggest that delta-GABA(A)Rs are involved in the secondary indirect regulation of the brain rhythms after 4-MMC.Peer reviewe