Matching Items (43,917)
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Description

5-HT1B receptors (5-HT1BRs) modulate behavioral effects of cocaine. Here we examined the effects of the 5-HT1BR agonist 5-propoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-pyrrolo[3,2-b]pyridine (CP94253) on spontaneous and cocaine-induced locomotion and on cocaine-primed reinstatement of conditioned place preference (CPP) in male mice given daily

5-HT1B receptors (5-HT1BRs) modulate behavioral effects of cocaine. Here we examined the effects of the 5-HT1BR agonist 5-propoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-pyrrolo[3,2-b]pyridine (CP94253) on spontaneous and cocaine-induced locomotion and on cocaine-primed reinstatement of conditioned place preference (CPP) in male mice given daily repeated injections of either saline or cocaine (15 mg/kg, IP) for 20 days. In the locomotor activity experiment, testing occurred both 1 and 20 days after the final injection. In the CPP experiment, mice underwent conditioning procedures while receiving the last of their daily injections, which were given either during or ≥2 h after CPP procedures. The CPP procedural timeline consisted of baseline preference testing (days 12–13 of the chronic regimen), conditioning (days 14–19, 2 daily 30-min sessions separated by 5 h), CPP test (day 21), extinction (days 22–34; no injections), CPP extinction test (day 35), and reinstatement test (day 36). Mice that had not extinguished received additional extinction sessions prior to reinstatement testing on day 42.

On test days, mice were pretreated with either saline or CP94253 (10 mg/kg, IP). Testing began 30 min later, immediately after mice were primed with either saline or cocaine (5 mg/kg for locomotion; 15 mg/kg for reinstatement). We found that CP94253 increased spontaneous locomotion in mice receiving repeated injections of either saline or cocaine when tested 1 day after the last injection, but had no effect on spontaneous locomotion after 20 days abstinence from repeated injections. Surprisingly, cocaine-induced locomotion was sensitized regardless of whether the mice had received repeated saline or cocaine. CP94253 attenuated expression of the sensitized locomotion after 20 days abstinence. A control experiment in noninjected, drug-naïve mice showed that CP94253 had no effect on spontaneous or cocaine-induced locomotion. Mice reinstated cocaine-CPP when given a cocaine prime, and CP94253 pretreatment attenuated cocaine reinstatement. The findings suggest that stress from repeated saline injections and/or co-housing with cocaine-injected mice may cross-sensitize with cocaine effects on locomotion and that CP94253 attenuates these effects, as well as reinstatement of cocaine-CPP. This study supports the idea that 5-HT1BR agonists may be useful anti-cocaine medications.

Contributors Der-Ghazarian, Taleen (Author) / Call, Tanessa (Author) / Scott, Samantha (Author) / Dai, Kael (Author) / Brunwasser, Samuel (Author) / Noudali, Sean (Author) / Pentkowski, Nathan (Author) / Neisewander, Janet (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2017-10-10
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Description

Design of novel infrastructure materials requires a proper understanding of the influence of microstructure on the desired performance. The priority is to seek new and innovative ways to develop sustainable infrastructure materials using natural resources and industrial solid

Design of novel infrastructure materials requires a proper understanding of the influence of microstructure on the desired performance. The priority is to seek new and innovative ways to develop sustainable infrastructure materials using natural resources and industrial solid wastes in a manner that is ecologically sustainable and yet economically viable. Structural materials are invariably designed based on mechanical performance. Accurate prediction of effective constitutive behavior of highly heterogeneous novel structural materials with multiple microstructural phases is a challenging task. This necessitates reliable classification and characterization of constituent phases in terms of their volume fractions, size distributions and intrinsic elastic properties, coupled with numerical homogenization technique. This paper explores a microstructure-guided numerical framework that derives inputs from nanoindentation and synchrotron x-ray tomography towards the prediction of effective constitutive response of novel sustainable structural materials so as to enable microstructure-guided design.

Contributors Das, Sumanta (Author) / Xiao, Xianghui (Author) / Chawla, Nikhilesh (Author) / Neithalath, Narayanan (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created 2017-02-22
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Description

Adolescence is a sensitive period for the development of romantic relationships. During this period the maturation of frontolimbic networks is particularly important for the capacity to regulate emotional experiences. In previous research, both functional magnetic resonance imaging (fMRI)

Adolescence is a sensitive period for the development of romantic relationships. During this period the maturation of frontolimbic networks is particularly important for the capacity to regulate emotional experiences. In previous research, both functional magnetic resonance imaging (fMRI) and dense array electroencephalography (dEEG) measures have suggested that responses in limbic regions are enhanced in adolescents experiencing social rejection. In the present research, we examined social acceptance and rejection from romantic partners as they engaged in a Chatroom Interact Task. Dual 128-channel dEEG systems were used to record neural responses to acceptance and rejection from both adolescent romantic partners and unfamiliar peers (N = 75). We employed a two-step temporal principal component analysis (PCA) and spatial independent component analysis (ICA) approach to statistically identify the neural components related to social feedback. Results revealed that the early (288 ms) discrimination between acceptance and rejection reflected by the P3a component was significant for the romantic partner but not the unfamiliar peer. In contrast, the later (364 ms) P3b component discriminated between acceptance and rejection for both partners and peers. The two-step approach (PCA then ICA) was better able than either PCA or ICA alone in separating these components of the brain's electrical activity that reflected both temporal and spatial phases of the brain's processing of social feedback.

Contributors Kuo, Ching-Chang (Author) / Ha, Phuong Thao (Author) / Ebbert, Ashley (Author) / Tucker, Don M. (Author) / Dishion, Thomas (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2017-05-31
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Description

Risks are inherent in construction projects. In order to manage risks, contingency amount is set aside usually in an escrow account. Cost contingency can be a handsome amount that would get blocked during the execution of the project

Risks are inherent in construction projects. In order to manage risks, contingency amount is set aside usually in an escrow account. Cost contingency can be a handsome amount that would get blocked during the execution of the project for further use, incurring constant opportunity cost. The stakeholders may wish to use this held amount for other endeavors during project execution. The managerial practices for dynamic contingency management are of extreme importance. Stakeholders anticipate risks and hindsight project performance by eyeing key performance indicators of a project to direct decisions. The aim of this research is to integrate project key performance indicators with future risk perception to develop a decision support system for facilitating cost contingency release requests. The model is expected to help decision making to ease the managerial burden ensuring effective use of contingency. The findings are not conclusive due to ongoing nature of research.

Contributors Ayub, Bilal (Author) / Thaheem, Muhammad Jamaluddin (Author) / Din, Zia Ud (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created 2016-05-20
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Description

The water resources and hydrologic extremes in Mediterranean basins are heavily influenced by climate variability. Modeling these watersheds is difficult due to the complex nature of the hydrologic response as well as the sparseness of hydrometeorological observations. In

The water resources and hydrologic extremes in Mediterranean basins are heavily influenced by climate variability. Modeling these watersheds is difficult due to the complex nature of the hydrologic response as well as the sparseness of hydrometeorological observations. In this work, we present a strategy to calibrate a distributed hydrologic model, known as TIN-based Real-time Integrated Basin Simulator (tRIBS), in the Rio Mannu basin (RMB), a medium-sized watershed (472.5 km[superscript 2]) located in an agricultural area in Sardinia, Italy. In the RMB, precipitation, streamflow and meteorological data were collected within different historical periods and at diverse temporal resolutions. We designed two statistical tools for downscaling precipitation and potential evapotranspiration data to create the hourly, high-resolution forcing for the hydrologic model from daily records. Despite the presence of several sources of uncertainty in the observations and model parameterization, the use of the disaggregated forcing led to good calibration and validation performances for the tRIBS model, when daily discharge observations were available. The methodology proposed here can be also used to disaggregate outputs of climate models and conduct high-resolution hydrologic simulations with the goal of quantifying the impacts of climate change on water resources and the frequency of hydrologic extremes within medium-sized basins.

Contributors Mascaro, Giuseppe (Author) / Piras, M. (Author) / Deidda, R. (Author) / Vivoni, Enrique (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created 2013-10-24
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Description

Cloud and fog droplets efficiently scavenge and process water-soluble compounds and, thus, modify the chemical composition of the gas and particle phases. The concentrations of dissolved organic carbon (DOC) in the aqueous phase reach concentrations on the order

Cloud and fog droplets efficiently scavenge and process water-soluble compounds and, thus, modify the chemical composition of the gas and particle phases. The concentrations of dissolved organic carbon (DOC) in the aqueous phase reach concentrations on the order of ~ 10 mgC L-1 which is typically on the same order of magnitude as the sum of inorganic anions. Aldehydes and carboxylic acids typically comprise a large fraction of DOC because of their high solubility. The dissolution of species in the aqueous phase can lead to (i) the removal of species from the gas phase preventing their processing by gas phase reactions (e.g., photolysis of aldehydes) and (ii) the formation of unique products that do not have any efficient gas phase sources (e.g., dicarboxylic acids).

We present measurements of DOC and select aldehydes in fog water at high elevation and intercepted clouds at a biogenically-impacted location (Whistler, Canada) and in fog water in a more polluted area (Davis, CA). Concentrations of formaldehyde, glyoxal and methylglyoxal were in the micromolar range and comprised ≤ 2% each individually of the DOC. Comparison of the DOC and aldehyde concentrations to those at other locations shows good agreement and reveals highest levels for both in anthropogenically impacted regions. Based on this overview, we conclude that the fraction of organic carbon (dissolved and insoluble inclusions) in the aqueous phase of clouds or fogs, respectively, comprises 2–~ 40% of total organic carbon. Higher values are observed to be associated with aged air masses where organics are expected to be more highly oxidized and, thus, more soluble. Accordingly, the aqueous/gas partitioning ratio expressed here as an effective Henry's law constant for DOC (KH*DOC) increases by an order of magnitude from 7 × 103 M atm-1 to 7 × 104 M atm-1 during the ageing of air masses.

The measurements are accompanied by photochemical box model simulations. These simulations are used to contrast two scenarios, i.e., an anthropogenically vs. a more biogenically impacted one as being representative for Davis and Whistler, respectively. Since the simplicity of the box model prevents a fully quantitative prediction of the observed aldehyde concentrations, we rather use the model results to compare trends in aldehyde partitioning and ratios. They suggest that the scavenging of aldehydes by the aqueous phase can reduce HO2 gas phase levels significantly by two orders of magnitude due to a weaker net source of HO2 production from aldehyde photolysis in the gas phase. Despite the high solubility of dicarbonyl compounds (glyoxal, methylglyoxal), their impact on the HO2 budget by scavenging is < 10% of that of formaldehyde. The overview of DOC and aldehyde measurements presented here reveals that clouds and fogs can be efficient sinks for organics, with increasing importance in aged air masses. Even though aldehydes, specifically formaldehyde, only comprise ~ 1% of DOC, their scavenging and processing in the aqueous phase might translate into significant effects in the oxidation capacity of the atmosphere.

Contributors Ervens, B. (Author) / Wang, Y. (Author) / Eagar, J. (Author) / Leaitch, W. R. (Author) / Macdonald, A. M. (Author) / Valsaraj, K. T. (Author) / Herckes, Pierre (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2013-05-21
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Description

Axion stars are hypothetical objects formed of axions, obtained as localized and coherently oscillating solutions to their classical equation of motion. Depending on the value of the field amplitude at the core |θ0| ≡ |θ(r = 0)|, the

Axion stars are hypothetical objects formed of axions, obtained as localized and coherently oscillating solutions to their classical equation of motion. Depending on the value of the field amplitude at the core |θ0| ≡ |θ(r = 0)|, the equilibrium of the system arises from the balance of the kinetic pressure and either self-gravity or axion self-interactions. Starting from a general relativistic framework, we obtain the set of equations describing the configuration of the axion star, which we solve as a function of |θ0|. For small |θ0| [< over ~] 1, we reproduce results previously obtained in the literature, and we provide arguments for the stability of such configurations in terms of first principles. We compare qualitative analytical results with a numerical calculation. For large amplitudes |θ0| [> over ~] 1, the axion field probes the full non-harmonic QCD chiral potential and the axion star enters the dense branch. Our numerical solutions show that in this latter regime the axions are relativistic, and that one should not use a single frequency approximation, as previously applied in the literature. We employ a multi-harmonic expansion to solve the relativistic equation for the axion field in the star, and demonstrate that higher modes cannot be neglected in the dense regime. We interpret the solutions in the dense regime as pseudo-breathers, and show that the life-time of such configurations is much smaller than any cosmological time scale.

Contributors Visinelli, Luca (Author) / Baum, Sebastian (Author) / Redondo, Javier (Author) / Freese, Katherine (Author) / Wilczek, Frank (Author) / Origins Project (Contributor)
Created 2017-12-06
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Description

Various biologically inspired flow field designs of the gas distributor (interconnector) have been designed and simulated. Their performance using Nafion-212 with humidified H2 and Air at 80 °C with the ANSYS Fluent Fuel Cell module software was evaluated.

Various biologically inspired flow field designs of the gas distributor (interconnector) have been designed and simulated. Their performance using Nafion-212 with humidified H2 and Air at 80 °C with the ANSYS Fluent Fuel Cell module software was evaluated. Novel interdigitated designs were optimized by obeying biologically inspired branching rules. These rules allow for more mathematically formal descriptions of flow field designs, enabling relatively simple optimization. The channel to land ratio was kept equivalent between designs with typical values between 0.8 and 1.0. The pressure drop and the current density distribution were monitored for each design on both anode and cathode sides. The most promising designs are expected to exhibit lower pressure drop however, low pressure drop can also be an indication of potential water flooding at higher operating current density. A biologically inspired interdigitated design with 9 inlet channels exhibited reduced pressure drop and improved current density distribution compared to all other interdigitated designs evaluated in this study. The simulated fuel cell performance data at ambient pressure with humidified H2 and air compares well with the experimental data using a single serpentine flow field design.

Contributors Arvay, Adam (Author) / French, Jason (Author) / Wang, Jui-Chieh (Author) / Peng, Xihong (Author) / Kannan, Arunachala Mada (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created 2015
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Description

Nasonia, a genus of four closely related parasitoid insect species, is a model system for genetic research. Their haplodiploid genetics (haploid males and diploid females) and interfertile species are advantageous for the genetic analysis of complex traits and

Nasonia, a genus of four closely related parasitoid insect species, is a model system for genetic research. Their haplodiploid genetics (haploid males and diploid females) and interfertile species are advantageous for the genetic analysis of complex traits and the genetic basis of species differences. A fine-scale genomic map is an important tool for advancing genetic studies in this system. We developed and used a hybrid genotyping microarray to generate a high-resolution genetic map that covers 79% of the sequenced genome of Nasonia vitripennis. The microarray is based on differential hybridization of species-specific oligos between N. vitripennis and Nasonia giraulti at more than 20,000 markers spanning the Nasonia genome. The map places 729 scaffolds onto the five linkage groups of Nasonia, including locating many smaller scaffolds that would be difficult to map by other means. The microarray was used to characterize 26 segmental introgression lines containing chromosomal regions from one species in the genetic background of another. These segmental introgression lines have been used for rapid screening and mapping of quantitative trait loci involved in species differences. Finally, the microarray is extended to bulk-segregant analysis and genotyping of other Nasonia species combinations. These resources should further expand the usefulness of Nasonia for studies of the genetic basis and architecture of complex traits and speciation.

Contributors Desjardins, Christopher A. (Author) / Gadau, Juergen (Author) / Lopez, Jacqueline A. (Author) / Niehuis, Oliver (Author) / Avery, Amanda R. (Author) / Loehlin, David W. (Author) / Richards, Stephen (Author) / Colbourne, John K. (Author) / Werren, John H. (Author) / College of Liberal Arts and Sciences (Contributor)
Created 2013-02-01
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Description

Background: The efficacy of deep brain stimulation (DBS) in Parkinson’s disease has been convincingly demonstrated in studies comparing motor performance with and without stimulation, but characterization of the stimulation dose-response curves has been limited.

Methods: In a series of

Background: The efficacy of deep brain stimulation (DBS) in Parkinson’s disease has been convincingly demonstrated in studies comparing motor performance with and without stimulation, but characterization of the stimulation dose-response curves has been limited.

Methods: In a series of case studies, eight subjects with Parkinson’s disease and bilateral DBS systems were evaluated at their clinically determined stimulation (CDS) and at three reduced amplitudes, ie, approximately 70%, 30%, and 0% of the CDS (MOD, LOW, and OFF, respectively). Performance was assessed using the motor section of the Unified Parkinson’s Disease Rating Scale (UPDRS-III), which includes subscores for tremor, bradykinesia, gait, posture, and tapping. Data at the reduced settings were analyzed to determine if individual subjects demonstrated a threshold-like response, which was defined as a dose-response curve in which one decrement in stimulation accounted for ≥70% of the maximum change observed. Day-to-day variability was assessed using the CDS data from the three different days.

Results: In the dose-response curves, two subjects exhibited a threshold-like response, four exhibited a graded change, and two did not exhibit substantial changes. For some subjects, variability in CDS performance across the three days exceeded the change observed when reducing amplitude to the MOD setting. Comparisons across this set of eight subjects demonstrated that the mean UPDRS-III and all but one subscore significantly increased (performance degraded) when amplitude was reduced from CDS to the LOW and OFF conditions, but there were no significant changes when amplitude was reduced from CDS to the MOD condition.

Conclusion: Individual differences in the DBS dose-response curves may provide opportunities to optimize clinical performance. Day-to-day variability in motor performance cautions against the use of a single UPDRS measurement in clinical selection of DBS settings.

Contributors Conovaloff, Alison (Author) / Krishnamurthi, Narayanan (Author) / Mahant, Padma (Author) / Samanta, Johan (Author) / Abbas, James (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created 2012-12-11