519 research outputs found
Genetic Regulation of Nicotine-Responsive Behaviors in the Nematode, C. elegans.
At its core, addiction is a pathological state of motivation. While motivation itself is an adaptive psychological tool, when the motivation to seek out and engage a specific pharmacological agent, such as nicotine, or a biologically relevant stimulus, such as highly palatable food, exerts undue control over the behavior of an animal, the adaptive tool of motivation is transformed into the maladaptive state of addiction. The insulin signaling system plays a vital role in motivated behaviors, particularly in food-seeking behavior. The transient receptor potential (TRP) channels, meanwhile, are deeply involved in the sensory systems necessary for an organism to monitor its environment in order to locate biologically relevant stimuli. Here, we explore a role for the insulin signaling system in the locomotor response of nematodes to an acute nicotine challenge as well as a role for TRP channels in mediating nicotine-approach behavior in these animals. The studies presented here suggest novel models for how drugs of abuse can usurp adaptive motivational processes. We demonstrate that nematodes with a compromised insulin signaling system respond to an acute nicotine challenge as though it were a depressant rather than a stimulant. This effect persists in both genetic and pharmacologic manipulations of the insulin signaling system. We also demonstrate that C. elegans will chemotax to a source of nicotine and that vanilloid TRP channels are necessary for this behavior. The findings from the studies presented here may serve to identify novel therapeutic targets for the treatment of nicotine abuse, which is a leading public health concern throughout the developed world.PhDNeuroscienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111391/1/neurosaw_1.pd
Analysis of the first gigantic jet recorded over continental North America
[1] Two low-light cameras near Marfa, Texas, recorded a gigantic jet over northern Mexico on 13 May 2005 at approximately 0423:50 UTC. Assuming that the farthest of two candidate storm systems was its source, the bright lower channel ended in a fork at around 50–59 km height with the very dim upper branches extended to 69–80 km altitude. During the time window containing the jet, extremely low frequency magnetic field recordings show that there was no fast charge moment change larger than 50 coulomb times kilometers (C km) but there was a larger and slower charge moment change of 520 C km over 70 ms. The likely parent thunderstorm was a high-precipitation supercell cluster containing a persistent mesocyclone, with radar echo tops of at least 17 km. However, photogrammetric analysis suggests that the gigantic jet occurred over the forward flank downdraft region with echo tops of 14 km. This part of the supercell may have had an inverted-polarity charge configuration as evidenced by positive cloud-to-ground lightning flashes (+CG) dominating over negative flashes (-CG), while -CGs occurred under the downwind anvil. Four minutes before the gigantic jet, -CG activity practically ceased in this area, while +CG rates increased, culminating during the 20 s leading up to the gigantic jet with four National Lightning Detection Network–detected +CGs. A relative lull in lightning activity of both polarities was observed for up to 1.5 min after the gigantic jet. The maturing storm subsequently produced 30 sprites between 0454 and 0820 UTC, some associated with extremely large impulse charge moment change values.Peer ReviewedPostprint (published version
Ecosystem conservation in multi-tenure reserve networks : the contribution of land outside of publicly protected areas
Multi-tenure reserve networks have been developed as a mechanism to improve cross tenure management and protection of biodiversity, but also as a means of accounting for biodiversity assets managed for conservation outside of protected areas on public land. We evaluated the contribution of multi-tenure reserve networks to enhancing the comprehensiveness and representativeness of ecosystems in publicly protected areas, using three Australian case studies. All networks contributed to enhancing comprehensiveness and representativeness, but this contribution varied between networks and between components of those networks. Significantly, components on private land and "other public land" in all three networks greatly enhanced the protection of some ecosystems at a subregional scale. The Grassy Box Woodlands Conservation Management Network, in particular made a substantial contribution to conservation, with most components protecting remnants of an endangered and under-represented ecosystem. Multi-reserve conservation networks not only act to protect threatened and under-reserved ecosystems, but they also provide a mechanism to account for this protection. Thus, multi-tenure reserve networks have the potential to provide increased knowledge and understanding to conservation planning decision making processes.<br /
The 'ForensOMICS' approach for postmortem interval estimation from human bone by integrating metabolomics, lipidomics, and proteomics
The establishment of large private nature reserves by conservation NGOs : key factors for successful implementation
Private nature reserves created by nongovernmental organizations (NGOs) are increasing, and their growing number and extent means that they can potentially contribute to biodiversity goals at a global scale. However, the success of these reserves depends on the legal, economic and institutional conditions framing their creation and management. We explored these conditions, and the opportunities and challenges facing conservation organizations in managing private nature reserves, across several countries, with an emphasis on Australia. Results from 17 semi-structured interviews with representatives of private conservation organizations indicated that while private reserves may enhance the conservation estate, challenges remain. Legal frameworks, especially tenure and economic laws, vary across and within countries, presenting conservation organizations with significant opportunities or constraints to owning and/or managing private nature reserves. Many acquired land without strategic acquisition procedures and secured funding for property acquisition but not management, affecting the long-term maintenance of properties. Other typical problems were tied to the institutional capacity of the organizations. Greater planning within organizations, especially financial planning, is required and NGOs must understand opportunities and constraints present in legislative frameworks at the outset. Organizations must establish their expertise gaps and address them. To this end, partnerships between organizations and/or with government can prove critical
Training and Transfer Effect of FluoroSim, an Augmented Reality Fluoroscopic Simulator for Dynamic Hip Screw Guidewire Insertion: A Single-Blinded Randomized Controlled Trial
BACKGROUND: FluoroSim, a novel fluoroscopic simulator, can be used to practice dynamic hip screw (DHS) guidewire insertion in a high-fidelity clinical scenario. Our aim was to demonstrate a training effect in undergraduate medical students who are not familiar with this operation and its simulation. METHODS: Forty-five undergraduate medical students were recruited and randomized to either training (n = 23) or control (n = 22) cohorts. The training cohort had more exposure to FluoroSim (5 attempts each week) over a 2-week period (with a 1-week washout period in between) compared with the control cohort (a single attempt 1 week apart) over a 2-week period. Five real-time objective performance metrics were recorded: (1) tip-apex distance (TAD) (mm), (2) predicted cut-out rate (%), (3) total procedural time (sec), (4) total number of radiographs (n), and (5) total number of guidewire retries (n). RESULTS: At baseline, there was no significant difference in the performance metrics, which confirmed the absence of a selection bias. The intragroup training effect demonstrated a significant improvement in all metrics for the training cohort only. A significant difference between groups was demonstrated as the training cohort significantly outperformed the control cohort in 3 metrics (procedural time [25%], number of radiographs [57%], and number of guidewire retries [100%]; p < 0.001). A learning curve showed an inversely proportional correlation between frequency of attempts and procedural time as well as the number of digital fluoroscopic radiographs that were made, indicating the development of psychomotor skills. There was also an improved baseline of the learning curve after the 1-week washout period, suggesting skill retention. CONCLUSIONS: Skill acquisition with the FluoroSim system was demonstrated with repeat exposure in a safe, radiation-free high-fidelity clinical simulation with actual operating room equipment. The task of DHS guidewire insertion requires cognitive and psychomotor skills that take a variable number of attempts to acquire, as demonstrated on the learning curve. Additional work is required to demonstrate that the skill tested by the FluoroSim is the same skill that is required for intraoperative DHS guidewire insertion. However, use of the FluoroSim provides improvement in skills with extra-clinical training opportunities for orthopaedic trainees. CLINICAL RELEVANCE: FluoroSim has demonstrated validity and training effect. It has the potential to be approved for possible use on patients in the operating room to help surgeons with the operation. Consequently, operating time, accuracy of TAD, and surgical outcomes may all be improved
FE Modelling of Mechanical Tensioning for Controlling Residual Stresses in Friction Stir Welds
The ‘ForensOMICS’ approach for postmortem interval estimation from human bone by integrating metabolomics, lipidomics, and proteomics
The combined use of multiple omics allows to study complex interrelated biological processes in their entirety. We applied a combination of metabolomics, lipidomics and proteomics to human bones to investigate their combined potential to estimate time elapsed since death (i.e., the postmortem interval [PMI]). This 'ForensOMICS' approach has the potential to improve accuracy and precision of PMI estimation of skeletonized human remains, thereby helping forensic investigators to establish the timeline of events surrounding death. Anterior midshaft tibial bone was collected from four female body donors before their placement at the Forensic Anthropology Research Facility owned by the Forensic Anthropological Center at Texas State (FACTS). Bone samples were again collected at selected PMIs (219-790-834-872days). Liquid chromatography mass spectrometry (LC-MS) was used to obtain untargeted metabolomic, lipidomic, and proteomic profiles from the pre- and post-placement bone samples. The three omics blocks were investigated independently by univariate and multivariate analyses, followed by Data Integration Analysis for Biomarker discovery using Latent variable approaches for Omics studies (DIABLO), to identify the reduced number of markers describing postmortem changes and discriminating the individuals based on their PMI. The resulting model showed that pre-placement metabolome, lipidome and proteome profiles were clearly distinguishable from post-placement ones. Metabolites in the pre-placement samples suggested an extinction of the energetic metabolism and a switch towards another source of fuelling (e.g., structural proteins). We were able to identify certain biomolecules with an excellent potential for PMI estimation, predominantly the biomolecules from the metabolomics block. Our findings suggest that, by targeting a combination of compounds with different postmortem stability, in the future we could be able to estimate both short PMIs, by using metabolites and lipids, and longer PMIs, by using proteins
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A GIS approach for predicting prehistoric site locations.
Use of geographic information system (GIS)-based predictive mapping to locate areas of high potential for prehistoric archaeological sites is becoming increasingly popular among archaeologists. Knowledge of the environmental variables influencing activities of original inhabitants is used to produce GIS layers representing the spatial distribution of those variables. The GIS layers are then analyzed to identify locations where combinations of environmental variables match patterns observed at known prehistoric sites. Presented are the results of a study to locate high-potential areas for prehistoric sites in a largely unsurveyed area of 39,000 acres in the Upper Chesapeake Bay region, including details of the analysis process. The project used environmental data from over 500 known sites in other parts of the region and the results corresponded well with known sites in the study area
An evaluation of Sea Search as a citizen science programme in Marine Protected Areas
Citizen science involves collaboration between multi-sector agencies and the public to address a natural resource management issue. The Sea Search citizen science programme involves community groups in monitoring and collecting subtidal rocky reef and intertidal rocky shore data in Victorian Marine Protected Areas (MPAs), Australia. In this study we compared volunteer and scientifically collected data and the volunteer motivation for participation in the Sea Search programme. Intertidal rocky shore volunteer-collected data was found to be typically comparable to data collected by scientists for species richness and diversity measures. For subtidal monitoring there was also no significant difference for species richness recorded by scientists and volunteers. However, low statistical power suggest only large changes could be detected due to reduced data replication. Generally volunteers recorded lower species diversity for biological groups compared to scientists, albeit not significant. Species abundance measures for algae species were significantly different between volunteers and scientists. These results suggest difficulty in identification and abundance measurements by volunteers and the need for additional training requirements necessary for surveying algae assemblages. The subtidal monitoring results also highlight the difficulties of collecting data in exposed rocky reef habitats with weather conditions and volunteer diver availability constraining sampling effort. The prime motivation for volunteer participation in Sea Search was to assist with scientific research followed closely by wanting to work close to nature. This study revealed two important themes for volunteer engagement in Sea Search: 1) volunteer training and participation and, 2) usability of volunteer collected data for MPA managers. Volunteer-collected data through the Sea Search citizen science programme has the potential to provide useable data to assist in informed management practices of Victoria’s MPAs, but requires the support and commitment from all partners involved.<br /
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