30 research outputs found
Monitoring of resistance to the pyrethroid cypermethrin in Brazilian Aedes aegypti (Diptera: Culicidae) populations collected between 2001 and 2003
Phylogeography of Sardinian Cave Salamanders (Genus Hydromantes) Is Mainly Determined by Geomorphology
Detecting the factors that determine the interruption of gene flow between populations is key to understanding how speciation occurs. In this context, caves are an excellent system for studying processes of colonization, differentiation and speciation, since they represent discrete geographical units often with known geological histories. Here, we asked whether discontinuous calcareous areas and cave systems represent major barriers to gene flow within and among the five species of Sardinian cave salamanders (genus Hydromantes) and whether intraspecific genetic structure parallels geographic distance within and among caves. We generated mitochondrial cytochrome b gene sequences from 184 individuals representing 48 populations, and used a Bayesian phylogeographic approach to infer possible areas of cladogenesis for these species and reconstruct historical and current dispersal routes among distinct populations. Our results show deep genetic divergence within and among all Sardinian cave salamander species, which can mostly be attributed to the effects of mountains and discontinuities in major calcareous areas and cave systems acting as barriers to gene flow. While these salamander species can also occur outside caves, our results indicate that there is a very poor dispersal of these species between separate cave systems
William Bloomquist, Doctor of Musical Arts recital, piano, June 2, 1980
Instrumentation: pian
Mapping the Surface of Sheet Flow Water in the Everglades
University of Florida (UF) researchers used airborne laser swath mapping (ALSM) to map the height of vegetation, relative to the surface of sheet flow water, in the Everglades. In less than three hours of flying, ALSM provided sub-decimeter precision measurements of the height and slope of the water surface over an area greater than 50 square kilometers. The RMS scatter of the measurements about the best fitting slope along a 14 kilometer transect was less than 4 cm. Two features of the UF ALSM system were of particular advantage in this project: coverage of the nadir provided by the oscillating mirror scanner, and intensity values of the return signals. Openings in the grasses allowed a small percentage of laser shots, at the nadir of the aircraft, to be reflected from the calm surface of the slowly flowing water. These nearly specular reflections produced intensity values five to ten times as strong as the diffuse reflections from the grasses. The ALSM observations had to be carefully calibrated for the unusually strong return signals, but once this was done the signal-to-noise ratio was excellent and the geometry could not have been better for determining the height of the water surface. This project demonstrated the unique capabilities of ALSM to quickly and accurately map remote wildlife habitats, in this case that of the Cape Sable Seaside Sparrow, an endangered species that builds nests within 15 cm of the surface of the water. Managers hope to use such measurements to plan and control the release of water in order to avoid inundating nests, hopefully helping the Cape Sable Seaside Sparrow to avoid extinction
Understanding the effects of forced and bubble-induced convection in transport-limited organic electrosynthesis
Organic electrosynthesis offers a sustainable path to decarbonize the chemical industry by integrating renewable energy into chemical manufacturing. However, achieving the selectivity and energy efficiency required for industrial applications is challenging due to the inherent mass transport limitations. Convection can mitigate mass transport limitations, but its impact on organic electrochemical processes remains poorly understood. We investigate the interplay between mass transport and electrochemical reaction rates under convective flows in the context of the electrosynthesis of adiponitrile, one of the largest organic electrochemical processes in the industry. We use experiments and data-driven predictive models to demonstrate that forced liquid convection and bubble-induced convection produce near-identical mass transport conditions when the corresponding Sherwood numbers—the ratio of convective mass transport to diffusive mass transport—are equal. Moreover, we show that the Faradaic efficiency (i.e., the electrochemical selectivity) scales with the Sherwood number for a given current density and reactant concentration. This scalability enables performance to be predicted irrespective of the convection mode employed to enhance mass transport. Our results provide a deeper understanding of mass transport in organic electrosynthesis and offer guidelines to enable more sustainable chemical manufacturing practices
IF YOU CANNOT TAKE THE HEAT, GET OUT OF THE CERRADO … RECOVERING THE EQUILIBRIUM AMENITY COST OF NONMARGINAL CLIMATE CHANGE IN BRAZIL
This paper presents an empirical technique for valuing large changes in nonmarketed local attributes (e.g., climate amenities) without data describing prices of locally traded commodities like housing. A model of endogenous sorting is used to identify individuals' indirect utility functions, from which the value of the change in the local attribute is recovered while accounting for equilibrium impacts on markets for labor and locally traded commodities. Annual amenity costs of Brazilian climate change are estimated to be between 8.1 billion for a moderate climate change scenario, depending upon the role of migration costs. Copyright Blackwell Publishing, Inc. 2007
Aryl propanolamines: comparison of activity at human β(3) receptors, rat β(3) receptors and rat atrial receptors mediating tachycardia
1. The in vitro activity of four aryl propanolamines was compared to two prototypic β(3) receptor agonists, CGP 12177 and CL316243 at the human β(3) receptor, the rat β(3) receptor in the stomach fundus and receptors mediating atrial tachycardia. 2. L-739,574 was the most potent (EC(50)=9 nM) and selective agonist at the human β(3) receptor with high maximal response (74% of the maximal response to isoproterenol). 3. A phenol-biaryl ether analogue possessed modest affinity for the human β(3) receptor (EC(50)=246 nM), but was highly efficacious with a maximal response 82% of the maximal response to isoproterenol. The other derivatives were intermediate in potency with low maximal responses. 4. These agonists at the human β(3) receptor did not activate the rat β(3) receptor in the rat stomach fundus. In fact, the aryl propanolamines (10(−6) M) inhibited CL316243-induced activation of the rat β(3) receptor. Thus, agonist activity at the human β(3) receptor translated into antagonist activity at the rat β(3) receptor. 5. L739,574 and the phenol biaryl ether increased heart rate via β(1) receptors. 6. Although CGP12177 produced atrial tachycardia, neither the indole sulphonamide nor biphenyl biaryl ether did, although both had high affinity for the human β(3) receptor. Thus, the atrial tachycardic receptor was not identical to the human β(3) receptor. 7. These studies (a) characterized four aryl propanolamines with high affinity at the human β(3) receptor, (b) found that they were antagonists at the rat β(3) receptor, an observation with profound implications for in vivo rat data, and (c) established that the rodent atrial non-β(1), β(2) or β(3) tachycardic receptor was also unrelated to the human β(3) receptor