MOLECULAR AND ENZYMATIC RESISTANCE OF CULEX TARSALIS TO PYRETHROID AND ORGANOPHOSPHATE INSECTICIDES

Culex tarsalis, a vector for diseases like West Nile virus, is evolving resistance to pyrethroid and organophosphate insecticides used for agriculture and vector control in Northern California. Common mechanisms of resistance in other Culex species include the target-site mutations kdr and ace-1 and increased levels of detoxification enzymes (esterases, GSTs, and oxidases). This study contained two parts: Pyrethroid Individual study and an Organophosphate Preliminary study. For the Pyrethroid Individual study, the goal was to compare the prevalence of kdr mutations and detoxification enzymes between pyrethroid susceptible and resistant Cx. tarsalis individuals in Northern California. For the Organophosphate Preliminary study, the goal was to survey current organophosphate resistance in Northern California Cx. tarsalis populations while identifying possible resistance mechanisms: ace-1 and variations in detoxification enzymes between populations and individuals. Individual mosquitoes previously categorized by resistance status from CDC bottle bioassays with permethrin or naled were prepared for both molecular and enzymatic testing by separating the legs of a mosquito from the remaining body. Legs were used to test for the presence of kdr and ace-1 mutation by qPCR and PCR respectively and confirmed by DNA sequencing while the bodies were used to test for levels of detoxification enzymes. A subset of individuals in the Organophosphate Preliminary study forwent bottle bioassays and were tested directly to make comparisons between populations without the stress of going into bottle bioassays. For the Pyrethroid Individual study, the greater number of F alleles present at the kdr target-site as well as increased levels of GST significantly increased survival when exposed to permethrin. Individuals with 2 F alleles and an active GST level greater than or equal to 0.052 ug/ml showed a higher survival rate than either mechanism independently demonstrating resistance to pyrethroids in Cx. tarsalis is likely the result of multiple resistance mechanisms acting collectively. For the Organophosphate Preliminary study, currently little resistance to naled (3%) was observed in Northern California Cx. tarsalis populations. No ace-1 mutations were found in the 208 individuals tested, however three did possess silent mutations at the target-site, suggesting surveillance is needed in the future. Between the small sample size and little resistance found in this preliminary study, there was no correlation between levels of detoxification enzymes from resistant and susceptible individuals. Due to differences in the biology of Cx. tarsalis and other mechanisms of resistance not looked at in this study it is hard to quantify definitive resistance mechanisms in Cx. tarsalis. From this study it appears that kdr mutation (L1014F) and increased levels of GST likely contribute at some level to resistance to pyrethroid insecticides in Cx. tarsalis

A comparative study of the Allium obtusum comples

The taxa of the Allium obtusum complex were examined morphologically, chromosomally, and with the use of the scanning electron microscope, Additional field studies included ultraviolet photography, caging experiments, and collection of insect visitors. Based on the cumulative information gathered during this investigation, of the 7 taxa previously proposed in this complex, 4 are considered to be valid: A. cratericola, A. obtusum, A. tribracteatum, and A. yosemitense, A new variety of A. obtusum, var, robustum is described. The base chromosome number among all members of the complex is seven, All species are diploid (2n=14), except for one population of A. cratericola which was found to be tetraploid (2n=28). Scanning electron microscope studies demonstrated the usefulness of outer bulb coat reticulation as a taxonomic character in differentiating between the species of the complex. Preliminary data collected during field investigations suggest that the strong absorption of ultraviolet radiation by all members of the complex relative to their reflecting soils may act as a visual cue to insects whose visual spectrum includes UV, Furthermore, in mature flowers the sexual parts of the inflorescence were found to be reflective under UV, perhaps acting as a guide to foraging insects. Caging experiments revealed that all members of the complex are capable of seed set in the absence of insect visitors. It was found, however, that the relative number of seeds produced was significantly higher among control populations. From the cumulative evidence obtained from these various approaches, supported by morphological resemblances, it can be concluded that the Allium obtusum complex represents a distinct and homogeneous assemblage of interrelated species and varieties

Concept design of a fast sail assisted feeder container ship

A fast sail assisted feeder container ship concept has been developed for the 2020 container market in the South East Asian and Caribbean regions.The design presented has met the requirements of an initial economic study, with a cargo capacity of 1270 twenty-foot equivalent unit containers, meeting the predictions of container throughput derived from historical data. In determining suitable vessel dimensions, account has also been taken for port and berthing restrictions, and considering hydrodynamic performance. The vessel has been designed for a maximum speed of 25 knots, allowing it to meet the demand for trade whilst reducing the number of ships operating on the routes considered.The design development of the fast feeder concept has involved rigorous analyses in a number of areas to improve the robustness of the final design. Model testing has been key to the development of the concept, by increasing confidence in the final result. This is due to the fact that other analysis techniques are not always appropriate or accurate. Two hull forms have been developed to meet requirements whilst utilising different propulsor combinations. This has enabled evaluation of efficiency gains resulting from different hydrodynamic phenomena for each design. This includes an evaluation of the hydrodynamic performance when utilising the sail system. This has been done using a combination of model test results and data from regression analysis. The final propulsor chosen is a contra-rotating podded drive arrangement. Wind tunnel testing has been used to maximise the performance of a Multi-wing sail system by investigating the effects of wing spacing, stagger and sail-container interactions. This has led to an increase in lift coefficient of 32% from initial predictions. The savings in power requirement due to the sail system are lower than initially predicted. However, another benefit of their installation, motion damping, has been identified. Whilst this has not been fully investigated, additional fuel savings are possible as well as improved seakeeping performance.The design is shown to be environmentally sustainable when compared to existing vessels operating on the proposed routes. This is largely due to the use of low-carbon and zero-sulphur fuel (liquefied natural gas) and improvements in efficiency regarding operation. This especially relates to cargo handling and scheduling. Green house gas emissions have been predicted to fall by 42% and 40% in the two regions should the design be adopted. These savings are also due to the use of the Multi-wing sail system, which contributes to reductions in power requirement of up to 6% when the vessel operates at its lower speed of 15 knots. It is demonstrated that the fast feeder is also economically feasible, with predicted daily cost savings of 27% and 33% in the South East Asian and Caribbean regions respectively. Thus the fast feeder container ship concept is a viable solution for the future of container transhipment. <br/

Taxonomy of the Allium Tribracteatum (Alliaceae) Complex

Allium tribracteatum and related species present a confusing array in California. Previous attempts at classification have been largely unsuccessful and keys that are available are unworkable. Herbarium and field studies were initiated to ascertain if previously overlooked characteristics could be found that would elucidate relationships within the group. Members of the complex were examined morphologically and cytologically. Based on these investigations four of the seven previously described taxa are considered valid: A. cratericola, A. obtusum, A. tribracteatum, and A. yosemitense. Allium tribracteatum is redefined and A. obtusum is divided into two varieties. Allium obtusum var. conspicuum var. n. is described. A key to the species is presented and relationships within the complex are discussed

Concept design of a fast sail assisted feeder container ship

An environmentally sustainable fast sail-assisted feeder-container ship concept, with a maximum speed of 25 knots, has been developed for the 2020 South East Asian and Caribbean container markets. The use of low-carbon and zero-sulphur fuel (liquefied natural gas) and improvements in operational efficiency (cargo handling and scheduling) mean predicted Green house gas emissions should fall by 42% and 40% in the two selected operational regions. The adoption of a Multi-wing sail system reduces power requirement by up to 6% at the lower ship speed of 15 knots. The predicted daily cost savings are respectively 27% and 33% in South East Asian and the Caribbean regions.Two hull forms with a cargo capacity of 1270TEU utilising different propulsion combinations were initially developed to meet operational requirements. Analysis &amp; tank testing of different hydrodynamic phenomena has enabled identification of efficiency gains for each design. The final propulsion chosen is a contra-rotating podded drive arrangement. Wind tunnel testing improved Multi-wing sail performance by investigating wing spacing, wing stagger and sail-container interactions. The associated lift coefficient was increased by 32%. Whilst savings in sail-assisted power requirement are lower than initially predicted an unexpected identified benefit was motion damping.The fast feeder-container ship is a proposed as a viable future method of container transhipment

Thinkfinity Grant: Interactive White Board: Status Report

The Mortola Library and Center for Teaching, Learning and Technology are working together on a joint pilot project utilizing the technology of interactive white boards (IWBs, also known by the brand name SMART Board). The mobile IWB serves three purposes: improve faculty development and increase integration of Web 2.0 tools into faculty development sessions, improvement of Information Literacy instruction sessions, and increase availability of new technologies for members of the Pace Community, students in particular, to use within the library

Enzyme-Linked Immunosorbent Assays Using the Recombinant gp51 and p24 of Bovine Leukemia Virus for Immunodetection of the Disease

Enzyme-linked immunosorbent assay (ELISA) is often used to test bovineleukemia virus (BLV) infection. However, commercially available kits test inSouth America detect only antibodies against the gp51 protein. With the aimto improve the sensitivity of the test, we developed here a two-step indirectdual ELISA test that included both proteins p24 and gp51, expressed andproduced in E. coli and baculovirus expression system respectively. Two hundredten BLV sera, stated as double positive or double negative by the combinationof commercial agar gel immunodiffusion (AGID) assay and a gp51-ELISA test, were tested with our in house dual rp24/rgp51 ELISA. Firstly, we checked the purified, optimized and standardized proteins as antigen by the checkerboard technique, and set up our in house ELISA test. The concordancecorrelation coefficient (CCC) and coefficient of variation (CV) intraplate repeatability levels were within the values established by the international standards.The statistical analysis demonstrated the value of sera correctly rankedhighest (93.48%), and for 0.3 cutoff, the sensitivity was 95.65% and the specificity 91.30%. In conclusion, the rp24/rgp51 ELISA developed and standardized here demonstrated to have good analytical characteristics to be considered for screening of BLV.Fil: Larsen, Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Corva, Santiago. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Panei, Carlos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Cátedra de Virología; ArgentinaFil: Geisler, Christoph. University Of Wyoming; Estados UnidosFil: Mortola, Eduardo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin