642 research outputs found
Rural Flies in the Urban Environment?
Because metropolitan areas in the United States have been expanding at a dramatic rate, there has been direct competition between rural and urban interests for land. Also, market pressures often make it most profitable for meat producers to locate as close to urban centers as possible. A resultant growing interface between rural and urban centers, coupled with inadequate understanding of the people between the two centers, provides a potential for problems to develop. This book generally summarizes one area of contention - flies: few people tolerate flies in any setting anymore
Amplified fragment length polymorphism used for inter- and intraspecific differentiation of screwworms (Diptera: Calliphoridae)
Morphologically, early immature stages of the economically important pest called screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), and non-pest secondary screwworms, Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), are nearly indistinguishable. Correct identification is crucial to the ongoing eradication and exclusion program protecting the United States, Mexico and Central America from reinvasion of screwworms persistent in South America and the Caribbean. Amplified fragment length polymorphism (AFLP) polymerase chain reaction was used to differentiate populations of C. hominivorax and to discriminate them from C. macellaria. Ten primer pairs screened for interspecific discrimination of C. hominivorax from C. macellaria showed 52 discrete bands, allowing the two species to be readily distinguished; divergent branches on resulting dendrograms showed 100% bootstrap support. C. macellaria populations grouped at the 92% level; C. hominivorax populations grouped at the 68% level. Of the 52 bands, seven were monomorphic for both species, 22 were specific to C. macellaria, ten were present only in C. hominivorax and the remaining 13 bands differentiated C. hominivorax populations. Separate studies using ten strains of C. hominivorax showed a higher level of genetic similarity within than between populations. Analyses using 72 bands (19 monomorphic bands, 53 bands grouped all ten strains at the 58% similarity level) resolved seven mutant strains from Mexico (85% similarity level); all ten strains were resolved at the 72% similarity level. Diagnostic bands were identified for species and strain identification. We conclude that AFLP can be a valuable tool for studies of interspecific and intraspecific genetic variation in screwworm populations
Genetic variability of the stable fly assessed on a global scale using amplified fragment length polymorphism
The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is a blood-feeding, economically important pest of animals and humans worldwide. Improved management strategies are essential and their development would benefit from studies on genetic diversity of stable flies. Especially if done on a global scale, such research could generate information necessary for the development and application of more efficient control methods. Herein we report on a genetic study of stable flies using amplified fragment length polymorphism, with samples of 10–40 individuals acquired from a total of 25 locations in the Nearctic, Neotropic, Palearctic, Afrotropic and Australasian biogeographical regions. We hypothesized that genetic differentiation would exist across geographical barriers. Although FST (0.33) was moderately high, the GST (0.05; representing genetic diversity between individuals) was very low; Nm values (representing gene flow) were high (9.36). The mismatch distribution and tests of neutrality suggested population expansion, with no genetic differentiation between locations. The analysis of molecular variance (AMOVA) results showed the majority of genetic diversity was within groups. The mantel test showed no correlation between geographic and genetic distance; this strongly supports theAMOVA results. These results suggest that stable flies did not show genetic differentiation but are panmictic, with no evidence of isolation by distance or across geographical barriers
Subcutaneous immunoglobulin replacement therapy in the treatment of patients with primary immunodeficiency disease
Antibody deficiency is the most frequently encountered primary immunodeficiency disease (PIDD) and patients who lack the ability to make functional immunoglobulin require life-long replacement therapy to prevent serious bacterial infections. Human serum immunoglobulin manufactured from pools of donated plasma can be administered intramuscularly, intravenously or subcutaneously. With the advent of well-tolerated preparations of intravenous immunoglobulin (IVIg) in the 1980s, the suboptimal painful intramuscular route of administration is no longer used. However, some patients continued to experience unacceptable adverse reactions to the intravenous preparations, and for others, vascular access remained problematic. Subcutaneously administered immunoglobulin (SCIg) provided an alternative delivery method to patients experiencing difficulties with IVIg. By 2006, immunoglobulin preparations designed exclusively for subcutaneous administration became available. They are therapeutically equivalent to intravenous preparations and offer patients the additional flexibility for the self-administration of their product at home. SCIg as replacement therapy for patients with primary antibody deficiencies is a safe and efficacious method to prevent serious bacterial infections, while maximizing patient satisfaction and improving quality of life
Tuning Fullerene Intercalation in a Poly (thiophene) derivative by Controlling the Polymer Degree of Self-Organisation
Controlling the nanoscale arrangement in polymer-fullerene organic solar cells is of paramount importance to boost the performance of such promising class of photovoltaic diodes. In this work, we use a pseudo-bilayer system made of poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene (PBTTT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), to acquire a more complete understanding of the diffusion and intercalation of the fullerene-derivative within the polymer layer. By exploiting morphological and structural characterisation techniques, we observe that if we increase the film solidification time the polymer develops a higher crystalline order, and, as a result, it does not allow fullerene molecules to intercalate between the polymer side-chains. Gaining insight into the detailed fullerene intercalation mechanism is important for the development of organic photovoltaic diodes (PVDs)
Mono- and double carbonylation of aryl iodides with amine nucleophiles in the presence of recyclable palladium catalysts immobilised on a supported dicationic ionic liquid phase
Silica modified with organic dicationic moieties proved to be an excellent support for palladium catalysts used in the aminocarbonylation of aryl iodides. By an appropriate choice of the reaction conditions, the same catalyst could be used for selective mono- or double carbonylations leading to amide and [small alpha]-ketoamide products, respectively. The best catalyst could be recycled for at least 10 consecutive runs with a loss of palladium below the detection limit. By the application of the new support, efficient catalyst recycling could be achieved under mild reaction conditions (under low pressure and in a short reaction time). Palladium-leaching data support a mechanism with dissolution-re-precipitation of the active palladium species
Resistance Status of House Flies (Diptera: Muscidae) from Southeastern Nebraska Beef Cattle Feedlots to Selected Insecticides
The status of resistance to three insecticides (permethrin, stirofos, and methoxychlor), relative to a laboratory-susceptible colony, was evaluated in Ăželd populations of house flies, Musca domestica L., collected from two beef cattle feedlots in southeastern Nebraska. Topical application and residual exposure to treated glass surfaces were suitable methods for determining the resistance status of house flies to permethrin, stirofos, or methoxychlor. However, in most cases, residual exposure was more sensitive in resistance detection (i.e., higher resistance ratios). The field populations tested were moderately resistant to permethrin (RR = 4.9-fold and RR = 7.3-fold, for topical application and residual exposure, respectively) and extremely resistant to stirofos and methoxychlor (not accurately quantifiable be cause of low mortality at the highest possible concentrations or doses). Probable explanations for the resistance status of these house fly populations and implications for global feedlot fly management are discussed
Dairy Farm Business Summary: Southeastern New York Region 1990
A.E. Ext. 91-17Dairy farmers throughout New York State have been participating in Cornell Cooperative Extension's farm business summary and analysis program since the early 1950's. Each participating farmer receives a comprehensive business summary and analysis of his or her farm business. The information in this report represents an average of the data submitted from farms in the Southeastern New York region
Morphological and Genetic Analysis of Four Color Morphs of Bean Leaf Beetle
Bean leaf beetle (BLB), Cerotoma trifurcata (Forster; Coleoptera: Chrysomelidae), exhibits considerable color variation but little is known about the underlying genetic structure and gene flow among color phenotypes. Genetic and morphological variation among four color phenotypes—green with spots (G+S), green without spots (G-S), red with spots (R+S) and red without spots (R-S)—were analyzed using amplified fragment length polymorphisms (AFLP) and morphometrics, respectively. AFLP generated 175 markers that showed ≥80% polymorphism. Analysis of molecular variance (AMOVA) indicated that genetic variation was greatest within phenotypes (82.6–84.0%); gene flow among the four phenotypes was relatively high (Nm = 3.82). The dendrogram and STRUCTURE analysis indicated some population divergence of G-S from the other phenotypes. Morphological parameters were similar among phenotypes except that R+S showed significant differences in weight and body-length. Canonical variables 1 and 2, based on average morphometric characters, accounted for 98% of the total variation; some divergence was indicated between G+S and R+S from each other and from the G-S/R-S BLB color morphs. The pattern of genetic variation indicated potential divergence of G-S and G+S from each other and from R-S and R+S. Although these results indicate that the four different color morphs are not genetically or reproductively isolated, there is some genetic differentiation/structure and morphological dissimilarity suggesting weak/incomplete isolation
Interactions between flow fields induced by surface dielectric barrier discharge arrays
This study investigates the flow field induced by a surface dielectric
barrier discharge (SDBD) system, known for its efficient pollution remediation
of volatile organic compounds (VOCs). We aim to understand the flow dynamics
that contribute to the high conversion observed in similar systems.
Experimental techniques, including schlieren imaging and particle image
velocimetry (PIV), applied with high temporal resolution, were used to analyse
the flow field. Complementary, fluid simulations are employed to investigate
the coupling between streamer and gas dynamics. Results show distinct fluid
field behaviours for different electrode configurations, which differ in
geometric complexity. The fluid field analysis of the most basic electrode
design revealed behaviours commonly observed in actuator studies. The
simulation results indicate the local information about the electron density as
well as different temporal phases of the fluid flow. The electrode design with
mostly parallel grid line structures exhibits confined vortices near the
surface. In contrast, an electrode design also used in previous studies, is
shown to promote strong gas transport through extended vortex structures,
enhancing gas mixing and potentially explaining the high conversion observed.Comment: submitted to Plasma Chemistry and Plasma Processing by Springer
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