Dopamine-D1 and δ-opioid receptors co-exist in rat striatal neurons

Cocaine’s enhancement of dopaminergic neurotransmission in the mesolimbic pathway plays a critical role in the initial reinforcing properties of this drug. However, other neurotransmitter systems are also integral to the addiction process. A large body of data indicates that opioids and dopamine together mediate emotional and reinforced behaviors. In support of this, cocaine-mediated increases in activation of dopamine D1 receptors (D1R) results in a desensitization of δ-opioid receptor (DOR) signaling through adenylyl cyclase (AC) in striatal neurons. To further define cellular mechanisms underlying this effect, the subcellular distribution of DOR and D1R was examined in the rat dorsolateral striatum. Dual immunoperoxidase/gold-silver detection combined with electron microscopy was used to identify DOR and D1R immunoreactivities in the same section of tissue. Semi-quantitative analysis revealed that a subset of dendritic cellular profiles exhibited both DOR and D1R immunoreactivities. Of 165 randomly sampled D1R immunoreactive profiles, 43% contained DOR. Similarly of 198 DOR-labeled cellular profiles, 52% contained D1R. The present data provide ultrastructural evidence for co-existence between DOR and D1R in striatal neurons, suggesting a possible mechanism whereby D1R modulation may alter DOR function

Rare Kaon Decays

The current status of rare kaon decay experiments is reviewed. New limits in the search for Lepton Flavor Violation are discussed, as are new measurements of the CKM matrix.Comment: 8 pages, 3 figures, LaTeX, presented at the 3rd International Conference on B Phyiscs and CP Violation, Taipei December 3-7, 199

Response of selected plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels

The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plants of the Merritt Island Wildlife Refuge, the citrus production, or the beekeeping industry of the island. Conditions were simulated in greenhouse exposure chambers and field chambers constructed to model the ideal continuous stirred tank reactor. A plant exposure system was developed for dispensing and monitoring the two major chemicals in SRF exhaust, HCl and Al203, and for dispensing and monitoring SRF exhaust (controlled fuel burns). Plants native to Merritt Island, Florida were grown and used as test species. Dose-response relationships were determined for short term exposure of selected plant species to HCl, Al203, and mixtures of the two to SRF exhaust

Volatile organic compounds in northern New England marine and continental environments during the ICARTT 2004 campaign

Volatile organic compound (VOC) measurements were made during the summer 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) at Thompson Farm (TF), a continental site 25 km from the New Hampshire coast, and Appledore Island (AI), a marine site 10 km off the Maine coast. The 24 h mean total hydroxyl radical (OH) reactivity (±1σ) for the suite of VOCs was 4.15 (±2.64) s−1 at TF and 2.57 (±1.10) s−1 at AI. The larger range of reactivity at TF was dominated by isoprene and the monoterpenes (mean combined reactivity = 2.01 (±2.57) s−1). The impact of local anthropogenic hydrocarbon sources such as liquefied petroleum gas (LPG) leakage and fossil fuel evaporation was evident at both sites. During the campaign, a propane flux of 9 (±2) × 109 molecules cm−2 s−1 was calculated from the linear regression of the mean 0100–0400 local time mixing ratios at TF. This is consistent with fluxes observed in 2003 at sites spread throughout the coastal area of New Hampshire indicating that LPG tank leakage is a major hydrocarbon source throughout the region. Net monoterpene fluxes during ICARTT at TF were 6 (±2), 1.8 (±0.4), 1.2 (±0.6), and 0.4 (±0.5) × 109 molecules cm−2 s−1 for α‐pinene, β‐pinene, camphene, and limonene, respectively. Comparison to estimated NO3 and O3 loss rates indicate that gross monoterpene emission rates were approximately double the observed net fluxes at TF and comparable to current monoterpene nighttime emission inventory estimates for the northeast

A Classification and Characterization of Two-Locus, Pure, Strict, Epistatic Models for Simulation and Detection

BackgroundThe statistical genetics phenomenon of epistasis is widely acknowledged to confound disease etiology. In order to evaluate strategies for detecting these complex multi-locus disease associations, simulation studies are required. The development of the GAMETES software for the generation of complex genetic models, has provided the means to randomly generate an architecturally diverse population of epistatic models that are both pure and strict, i.e. all n loci, but no fewer, are predictive of phenotype. Previous theoretical work characterizing complex genetic models has yet to examine pure, strict, epistasis which should be the most challenging to detect. This study addresses three goals: (1) Classify and characterize pure, strict, two-locus epistatic models, (2) Investigate the effect of model ‘architecture’ on detection difficulty, and (3) Explore how adjusting GAMETES constraints influences diversity in the generated models

Graduate Quantum Mechanics Reform

We address four main areas in which graduate quantum mechanics education can be improved: course content, textbook, teaching methods, and assessment tools. We report on a three year longitudinal study at the Colorado School of Mines using innovations in all these areas. In particular, we have modified the content of the course to reflect progress in the field in the last 50 years, used textbooks that include such content, incorporated a variety of teaching techniques based on physics education research, and used a variety of assessment tools to study the effectiveness of these reforms. We present a new assessment tool, the Graduate Quantum Mechanics Conceptual Survey, and further testing of a previously developed assessment tool, the Quantum Mechanics Conceptual Survey. We find that graduate students respond well to research-based techniques that have been tested mainly in introductory courses, and that they learn much of the new content introduced in each version of the course. We also find that students' ability to answer conceptual questions about graduate quantum mechanics is highly correlated with their ability to solve calculational problems on the same topics. In contrast, we find that students' understanding of basic undergraduate quantum mechanics concepts at the modern physics level is not improved by instruction at the graduate level.Comment: accepted to American Journal of Physic

Characterisation of the Upper Respiratory Tract Virome of Feedlot Cattle and its Association with Bovine Respiratory Disease

Bovine respiratory disease (BRD) is a major health problem within the global cattle industry. This disease has a complex aetiology, with viruses playing an integral role. In this study, metagenomics was used to sequence viral nucleic acids in the nasal swabs of BRD affected cattle. Viruses detected included those well known for their association with BRD in Australia (bovine viral diarrhea virus 1), as well as viruses known to be present but not fully characterised (bovine coronavirus) and viruses that have not been reported in BRD affect cattle in Australia (bovine rhinitis, bovine influenza D, and bovine nidovirus). Nasal swabs from a case control study were subsequently tested for 10 viruses and the presence of at least one virus was found to be significantly associated with BRD. Some of the more recently detected viruses had inconsistent association with BRD. Full genome sequences for bovine coronavirus, a virus increasingly associated with BRD, and bovine nidovirus were complete. Both viruses belong to the Coronaviridae family, which are frequently associated with disease in mammals. This study has provided greater insights into the viral pathogens associated with BRD and highlighted the need for further studies to elucidate more precisely the roles viruses play in BRD

Characterisation of the Upper Respiratory Tract Virome of Feedlot Cattle and its Association with Bovine Respiratory Disease

Bovine respiratory disease (BRD) is a major health problem within the global cattle industry. This disease has a complex aetiology, with viruses playing an integral role. In this study, metagenomics was used to sequence viral nucleic acids in the nasal swabs of BRD affected cattle. Viruses detected included those well known for their association with BRD in Australia (bovine viral diarrhea virus 1), as well as viruses known to be present but not fully characterised (bovine coronavirus) and viruses that have not been reported in BRD affect cattle in Australia (bovine rhinitis, bovine influenza D, and bovine nidovirus). Nasal swabs from a case control study were subsequently tested for 10 viruses and the presence of at least one virus was found to be significantly associated with BRD. Some of the more recently detected viruses had inconsistent association with BRD. Full genome sequences for bovine coronavirus, a virus increasingly associated with BRD, and bovine nidovirus were complete. Both viruses belong to the Coronaviridae family, which are frequently associated with disease in mammals. This study has provided greater insights into the viral pathogens associated with BRD and highlighted the need for further studies to elucidate more precisely the roles viruses play in BRD

Is it still worth searching for lepton flavor violation in rare kaon decays?

Prospective searches for lepton flavor violation (LFV) in rare kaon decays at the existing and future intermediate-energy accelerators are considered. The proposed studies are complementary to LFV searches in muon-decay experiments and offer a unique opportunity to probe models with approximately conserved fermion-generation quantum number with sensitivity superior to that in other processes. Consequently, new searches for LFV in kaon decays are an important and independent part of the general program of searches for lepton flavor violation in the final states with charged leptons.Comment: 30 pages, 10 figures. An extended version of the talk given at the Chicago Flavor Seminar, February 27, 2004. In the new version some misprints were corrected and some new data for LFV-processes were added. The main content of the paper was not changed. The paper is published in Yad. Fiz. 68, 1272 (2005