292 research outputs found
Assessing Fitness of Culex pipiens Mosquitoes Selected for Enhanced Survival to Methoprene
West Nile virus (WNV) is the most widespread arthropod-borne viral disease in the United States and is transmitted primarily by Culex pipiens. Methoprene is a pesticide used to control mosquito populations. Evolution of resistance threatens the longevity of any given insecticide with continued use. The objective of this research is to examine any fitness costs associated with resistance to methoprene in Cx. pipiens. Fitness will be examined by measuring wing length in laboratory-reared methoprene resistant and susceptible colonies of Cx. pipiens. Wing length serves as a proxy for body size. It is hypothesized that methoprene resistance in Cx. pipiens mosquito populations will result in fitness costs, such as reduced wing size
Bartonella prevalence in fleas isolated from populations of Uinta Ground Squirrels in Logan Canyon Utah
Susceptibility of Wild-Caught Lutzomyia longipalpis (Diptera: Psychodidae) Sand Flies to Insecticide After an Extended Period of Exposure in Western São Paulo, Brazil
Background In Brazil, members of the sand fly species complex Lutzomyia longipalpis transmit Leishmania infantum, a protist parasite that causes visceral leishmaniasis. Male Lu. longipalpis produce a sex pheromone that is attractive to both females and males. During a cluster randomised trial, to determine the combined effect of synthetic sex-aggregation pheromone and insecticide on Le. infantum transmission Lu. longipalpis had been continuously exposed to insecticide for 30 months. The objective of this study was to determine the effect of continuous exposure to the insecticides used in the trial on the susceptibility of Lu. longipalpis population. Methods During the trial the sand flies had been exposed to either lambda-cyhalothrin [pheromone + residual insecticide spray (PI)], deltamethrin [dog collars (DC)] or no insecticide [control (C)], for 30 months (November 2012 to April 2015). The insecticide treatment regime was kept in place for an additional 12 months (May 2015-April 2016) during this susceptibility study. Sand flies collected from the field were exposed to WHO insecticide-impregnated papers cyhalothrin (0.05%), deltamethrin (0.5%) and control (silicone oil) in a modified WHO insecticide exposure trial to determine their susceptibility. Results We collected 788 Lu. longipalpis using CDC-light traps in 31 municipalities across the three trial arms. Probit analysis showed that the knockdown times (KDTs) of Lu. longipalpis collected from the lambda-cyhalothrin exposed PI-arm [KDT50: 31.1 min, confidence interval (CI): 29.6–32.6 and KDT90: 44.2 min, CI: 42.1–46.7] were longer than the KDTs from the non-insecticide-treated C-arm (KDT50: 26.3 min, CI: 25.1–27.6 and KDT90: 38.2, CI: 36.5–40.2) (no-overlapping 95% CIs). KDTs of Lu. longipalpis collected from the deltamethrin exposed DC-arm had similar values (KDT50: 13.7 min, CI: 10.1–16.2 and KDT90: 26.7 min, CI: 21.8–30.6) to those for the C-arm (KDT50: 13.5 min; CI: 12.2–14.8 and KDT90: 23.2 min, CI: 21.4–25.4) (overlapping CIs). The wild-caught unexposed Lu. longipalpis (C-arm), took approximately twice as long to knock down as laboratory-colonised specimens for both insecticides. Conclusions Our study reveals slight changes in KDT, in sand flies after prolonged exposure to lambda-cyhalothrin in the presence of pheromone. These changes are not considered to have reached the reference levels indicative of resistance in sand flies suggesting that pheromone and insecticide treatment at the level indicated in this study do not constitute a significant risk of increased insecticide resistance. Prolonged exposure to deltamethrin in dog collars did not result in changes to KDT
Burrowing owls, Pulex irritans and plague
Western burrowing owls (Athene cunicularia hypugaea) are small, ground-dwelling owls ofwestern North America that frequent prairie dog (Cynomys spp.) towns and other grasslands.As they rely on rodent prey and occupy burrows once or concurrently inhabited by fossorialmammals, the owls often harbor fleas. We examined the potential role of fleas found onburrowing owls in plague dynamics by evaluating prevalence of Yersinia pestis in fleas and inowl blood. During 2012-2013 fleas and blood were collected from burrowing owls in portionsof five states with endemic plague: Idaho, Oregon, Washington, Colorado, and South Dakota.Fleas were enumerated, taxonomically identified, pooled by nest and assayed for Y. pestis usingculturing and molecular (PCR) approaches. Owl blood underwent serological analysis for plagueantibodies and nested PCR for detection of Y. pestis. Of \u3e4750 fleas collected from owls, Pulexirritans, a known plague vector in portions of its range, comprised more than 99.4%. However,diagnostic tests for Y. pestis of flea pools (culturing and PCR) and owl blood (PCR and serology)were negative. Thus, despite that fleas were prevalent on burrowing owls, and the potentialfor a relationship with burrowing owls as a phoretic host of infected fleas exists, we found noevidence of Y. pestis in sampled fleas or in owls that harbored them. We suggest that studiessimilar to those reported here during plague epizootics will be especially useful for confirmingthese results
Diagnostic Doses and Times for Phlebotomus papatasi and Lutzomiya longipalpis Sand Flies (Diptera: Psychodidae: Phleboominae) Using the CDC Bottle Bioassay to Assess Insecticide Resistance
Background: Insecticide resistance to synthetic chemical insecticides is a worldwide concern in phlebotomine sand flies (Diptera: Psychodidae), the vectors of Leishmania spp. parasites. The CDC bottle bioassay assesses resistance by testing populations against verified diagnostic doses and diagnostic times for an insecticide, but the assay has been used limitedly with sand flies. The objective of this study was to determine diagnostic doses and diagnostic times for laboratory Lutzomyia longipalpis (Lutz & Nieva) and Phlebotomus papatasi (Scopoli) to ten insecticides, including pyrethroids, organophosphates, carbamates, and DDT, that are used worldwide to control vectors.
Methods: Bioassays were conducted in 1,000-ml glass bottles each containing 10–25 sand flies from laboratory colonies of L. longipalpis or P. papatasi. Four pyrethroids, three organophosphates, two carbamates and one organochlorine, were evaluated. A series of concentrations were tested for each insecticide, and four replicates were conducted for each concentration. Diagnostic doses were determined only during the exposure bioassay for the organophosphates and carbamates. For the pyrethroids and DDT, diagnostic doses were determined for both the exposure bioassay and after a 24-hour recovery period.
Results: Both species are highly susceptible to the carbamates as their diagnostic doses are under 7.0 μg/ml. Both species are also highly susceptible to DDT during the exposure assay as their diagnostic doses are 7.5 μg/ml, yet their diagnostic doses for the 24-h recovery period are 650.0 μg/ml for Lu. longipalpis and 470.0 μg/ml for P. papatasi.
Conclusions: Diagnostic doses and diagnostic times can now be incorporated into vector management programs that use the CDC bottle bioassay to assess insecticide resistance in field populations of Lu. longipalpis and P. papatasi. These findings provide initial starting points for determining diagnostic doses and diagnostic times for other sand fly vector species and wild populations using the CDC bottle bioassay
Diagnostic Doses and Times for Phlebotomus papatasi and Lutzomiya longipalpis Sand Flies (Diptera: Psychodidae: Phleboominae) Using the CDC Bottle Bioassay to Assess Insecticide Resistance
Background: Insecticide resistance to synthetic chemical insecticides is a worldwide concern in phlebotomine sand flies (Diptera: Psychodidae), the vectors of Leishmania spp. parasites. The CDC bottle bioassay assesses resistance by testing populations against verified diagnostic doses and diagnostic times for an insecticide, but the assay has been used limitedly with sand flies. The objective of this study was to determine diagnostic doses and diagnostic times for laboratory Lutzomyia longipalpis (Lutz & Nieva) and Phlebotomus papatasi (Scopoli) to ten insecticides, including pyrethroids, organophosphates, carbamates, and DDT, that are used worldwide to control vectors.
Methods: Bioassays were conducted in 1,000-ml glass bottles each containing 10–25 sand flies from laboratory colonies of L. longipalpis or P. papatasi. Four pyrethroids, three organophosphates, two carbamates and one organochlorine, were evaluated. A series of concentrations were tested for each insecticide, and four replicates were conducted for each concentration. Diagnostic doses were determined only during the exposure bioassay for the organophosphates and carbamates. For the pyrethroids and DDT, diagnostic doses were determined for both the exposure bioassay and after a 24-hour recovery period.
Results: Both species are highly susceptible to the carbamates as their diagnostic doses are under 7.0 μg/ml. Both species are also highly susceptible to DDT during the exposure assay as their diagnostic doses are 7.5 μg/ml, yet their diagnostic doses for the 24-h recovery period are 650.0 μg/ml for Lu. longipalpis and 470.0 μg/ml for P. papatasi.
Conclusions: Diagnostic doses and diagnostic times can now be incorporated into vector management programs that use the CDC bottle bioassay to assess insecticide resistance in field populations of Lu. longipalpis and P. papatasi. These findings provide initial starting points for determining diagnostic doses and diagnostic times for other sand fly vector species and wild populations using the CDC bottle bioassay
Erratum to: How Can Psychological Science Inform Research About Genetic Counseling for Clinical Genomic Sequencing?
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147141/1/jgc40372.pd
How Can Psychological Science Inform Research About Genetic Counseling for Clinical Genomic Sequencing?
Next generation genomic sequencing technologies (including whole genome or whole exome sequencing) are being increasingly applied to clinical care. Yet, the breadth and complexity of sequencing information raise questions about how best to communicate and return sequencing information to patients and families in ways that facilitate comprehension and optimal health decisions. Obtaining answers to such questions will require multidisciplinary research. In this paper, we focus on how psychological science research can address questions related to clinical genomic sequencing by explaining emotional, cognitive, and behavioral processes in response to different types of genomic sequencing information (e.g., diagnostic results and incidental findings). We highlight examples of psychological science that can be applied to genetic counseling research to inform the following questions: (1) What factors influence patients’ and providers’ informational needs for developing an accurate understanding of what genomic sequencing results do and do not mean?; (2) How and by whom should genomic sequencing results be communicated to patients and their family members?; and (3) How do patients and their families respond to uncertainties related to genomic information?Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147034/1/jgc40193.pd
Mid-infrared VIPA Spectrometer for Rapid and Broadband Trace Gas Detection
We present and characterize a 2-D imaging spectrometer based on a
virtually-imaged phased array (VIPA) disperser for rapid, high-resolution
molecular detection using mid-infrared (MIR) frequency combs at 3.1 and 3.8 \mu
m. We demonstrate detection of CH4 at 3.1 \mu m with >3750 resolution elements
spanning >80 nm with ~600 MHz resolution in a <10 \mu s acquisition time. In
addition to broadband detection, rapid, time-resolved single-image detection is
demonstrated by capturing dynamic concentration changes of CH4 at a rate of
~375 frames per second. Changes in absorption above the noise floor of 5\times
10-4 are readily detected on the millisecond time scale, leading to important
future applications such as real time monitoring of trace gas concentrations
and detection of reactive intermediates
Operationalizing the Reciprocal Engagement Model of Genetic Counseling Practice: a Framework for the Scalable Delivery of Genomic Counseling and Testing
With the advent of widespread genomic testing for diagnostic indications and disease risk assessment, there is increased need to optimize genetic counseling services to support the scalable delivery of precision medicine. Here, we describe how we operationalized the reciprocal engagement model of genetic counseling practice to develop a framework of counseling components and strategies for the delivery of genomic results. This framework was constructed based upon qualitative research with patients receiving genomic counseling following online receipt of potentially actionable complex disease and pharmacogenomics reports. Consultation with a transdisciplinary group of investigators, including practicing genetic counselors, was sought to ensure broad scope and applicability of these strategies for use with any large‐scale genomic testing effort. We preserve the provision of pre‐test education and informed consent as established in Mendelian/single‐gene disease genetic counseling practice. Following receipt of genomic results, patients are afforded the opportunity to tailor the counseling agenda by selecting the specific test results they wish to discuss, specifying questions for discussion, and indicating their preference for counseling modality. The genetic counselor uses these patient preferences to set the genomic counseling session and to personalize result communication and risk reduction recommendations. Tailored visual aids and result summary reports divide areas of risk (genetic variant, family history, lifestyle) for each disease to facilitate discussion of multiple disease risks. Post‐counseling, session summary reports are actively routed to both the patient and their physician team to encourage review and follow‐up. Given the breadth of genomic information potentially resulting from genomic testing, this framework is put forth as a starting point to meet the need for scalable genetic counseling services in the delivery of precision medicine.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147027/1/jgc41111.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147027/2/jgc41111-sup-0001.pd
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