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  1. Book ; Online: Suppressing parametric instabilities in LIGO using low-noise acoustic mode dampers

    Biscans, S. / Gras, S. / Blair, C. D. / Driggers, J. / Evans, M. / Fritschel, P. / Hardwick, T. / Mansell, G.

    2019  

    Abstract: Interferometric gravitational-wave detectors like LIGO need to be able to measure changes in their arm lengths of order $10^{-18}~$m or smaller. This requires very high laser power in order to raise the signal above shot noise. One significant limitation ...

    Abstract Interferometric gravitational-wave detectors like LIGO need to be able to measure changes in their arm lengths of order $10^{-18}~$m or smaller. This requires very high laser power in order to raise the signal above shot noise. One significant limitation to increased laser power is an opto-mechanical interaction between the laser field and the detector's test masses that can form an unstable feedback loop. Such parametric instabilities have long been studied as a limiting effect at high power, and were first observed to occur in LIGO in 2014. Since then, passive and active means have been used to avoid these instabilities, though at power levels well below the final design value. Here we report on the successful implementation of tuned, passive dampers to tame parametric instabilities in LIGO. These dampers are applied directly to all interferometer test masses to reduce the quality factors of their internal vibrational modes, while adding a negligible amount of noise to the gravitational-wave output. In accordance with our model, the measured mode quality factors have been reduced by at least a factor of ten with no visible increase in the interferometer's thermal noise level. We project that these dampers should remove most of the parametric instabilities in LIGO when operating at full power, while limiting the concomitant increase in thermal noise to approximately 1%.

    Comment: 11 pages, 8 figures
    Keywords Physics - Applied Physics ; Astrophysics - Instrumentation and Methods for Astrophysics
    Subject code 621
    Publishing date 2019-09-17
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article: Effect of La Crosse virus infection on insemination rates in female Aedes triseriatus (Diptera: Culicidae).

    Gabitzsch, E S / Blair, C D / Beaty, B J

    Journal of medical entomology

    2006  Volume 43, Issue 5, Page(s) 850–852

    Abstract: Aedes triseriatus (Say) (Diptera: Culicidae) females orally infected with La Crosse virus after ingesting an infectious bloodmeal were compared for mating efficiency with females that ingested a noninfectious bloodmeal. After 14-d extrinsic incubation to ...

    Abstract Aedes triseriatus (Say) (Diptera: Culicidae) females orally infected with La Crosse virus after ingesting an infectious bloodmeal were compared for mating efficiency with females that ingested a noninfectious bloodmeal. After 14-d extrinsic incubation to allow for dissemination of the infection, all females were offered a second noninfectious bloodmeal and were placed in cages with age-matched males for 5 d. After 6 d, insemination rates were determined by detection of sperm in the spermathecae. Insemination rates of the La Crosse virus-infected females were significantly greater than in uninfected females.
    MeSH term(s) Aedes/physiology ; Aedes/virology ; Animals ; Female ; Insemination/physiology ; La Crosse virus/physiology ; Male ; Sexual Behavior, Animal/physiology ; Time Factors
    Language English
    Publishing date 2006-09
    Publishing country England
    Document type Comparative Study ; Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 410635-0
    ISSN 0022-2585
    ISSN 0022-2585
    DOI 10.1603/0022-2585(2006)43[850:eolcvi]2.0.co;2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Annotation and expression profiling of apoptosis-related genes in the yellow fever mosquito, Aedes aegypti

    Bryant, B / Blair, C.D / Olson, K.E / Clem, R.J

    Insect biochemistry and molecular biology. 2008 Mar., v. 38, issue 3

    2008  

    Abstract: Apoptosis has been extensively studied in Drosophila by both biochemical and genetic approaches, but there is a lack of knowledge about the mechanisms of apoptosis regulation in other insects. In mosquitoes, apoptosis occurs during Plasmodium and ... ...

    Abstract Apoptosis has been extensively studied in Drosophila by both biochemical and genetic approaches, but there is a lack of knowledge about the mechanisms of apoptosis regulation in other insects. In mosquitoes, apoptosis occurs during Plasmodium and arbovirus infection in the midgut, suggesting that apoptosis plays a role in mosquito innate immunity. We searched the Aedes aegypti genome for apoptosis-related genes using Drosophila and Anopheles gambiae protein sequences as queries. In this study we have identified eleven caspases, three inhibitor of apoptosis (IAP) proteins, a previously unreported IAP antagonist, and orthologs of Drosophila Ark, Dnr1, and BG4 (also called dFadd). While most of these genes have been previously annotated, we have improved the annotation of several of them, and we also report the discovery of four previously unannotated apoptosis-related genes. We examined the developmental expression profile of these genes in Ae. aegypti larvae, pupae and adults, and we also studied the function of a novel IAP antagonist, IMP. Expression of IMP in mosquito cells caused apoptosis, indicating that it is a functional pro-death protein. Further characterization of these genes will help elucidate the molecular mechanisms of apoptosis regulation in Ae. aegypti.
    Keywords Aedes aegypti ; genomics ; apoptosis ; genes ; insect proteins ; regulatory proteins ; amino acid sequences ; sequence homology ; phylogeny ; gene expression regulation ; developmental stages ; caspases
    Language English
    Dates of publication 2008-03
    Size p. 331-345.
    Document type Article
    ZDB-ID 1483248-3
    ISSN 1879-0240 ; 0965-1748
    ISSN (online) 1879-0240
    ISSN 0965-1748
    DOI 10.1016/j.ibmb.2007.11.012
    Database NAL-Catalogue (AGRICOLA)

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  4. Article: Mosquito Species Richness, Composition, and Abundance along Habitat-Climate-Elevation Gradients in the Northern Colorado Front Range

    Eisen, L / Bolling, B.G / Blair, C.D / Beaty, B.J / Moore, C.G

    Journal of medical entomology. 2008 July, v. 45, no. 4

    2008  

    Abstract: We exploited elevation gradients (1,500-2,400 m) ranging from plains to montane areas along the Poudre River and Big Thompson River in the northern Colorado Front Range to determine how mosquito species richness, composition, and abundance change along ... ...

    Abstract We exploited elevation gradients (1,500-2,400 m) ranging from plains to montane areas along the Poudre River and Big Thompson River in the northern Colorado Front Range to determine how mosquito species richness, composition, and abundance change along natural habitat-climate-elevation gradients. Mosquito collections in 26 sites in 2006 by using CO2-baited CDC light traps yielded a total of 7,136 identifiable mosquitoes of 27 species. Commonly collected species included Aedes vexans (Meigen) (n = 4,722), Culex tarsalis Coquillett (n = 825), Ochlerotatus increpitus (Dyar) (n = 546), Ochlerotatus trivittatus (Coquillett) (n = 303), Aedes cinereus Meigen (n = 280), Ochlerotatus melanimon (Dyar) (n = 146), Ochlerotatus dorsalis (Meigen) (n = 67), Culiseta inornata (Williston) (n = 52), Ochlerotatus pullatus (Coquillett) (n = 38), Ochlerotatus spencerii idahoensis (Theobald) (n = 37), and Culex pipiens L. (n = 29). Species richness was highest in plains habitats at elevations below 1,600 m. Numerous species were found exclusively or predominantly at low elevations below 1,700 m [Anopheles earlei Vargas, Anopheles freeborni Aitken, Coquilletidia perturbans (Walker), Culex erythrothorax (Dyar), Cx. pipiens, Culex territans Walker, Oc. dorsalis, Ochlerotatus hendersoni (Cockerell), Oc. melanimon, and Oc. trivittatus], whereas others occurred predominantly at high elevations above 2,300 m [Ae. cinereus, Culiseta incidens (Thomson), Culiseta morsitans (Theoblad), Ochlerotatus cataphylla (Dyar), Ochlerotatus intrudens (Dyar), Oc. pullatus, and Ochlerotatus punctor (Kirby)]. Ae. vexans and Cx. tarsalis were abundant in the plains (<1,600 m; mean June-August temperature >19.5°C), occurred at low abundances in foothills and low montane areas (1,610-1,730 m; 18.0-19.5°C), and they were collected only sporadically in montane areas above 1,750 m (mean June-August temperature <17.5°C). These findings suggest that future climate warming may lead to shifts in distribution patterns of West Nile virus vectors (e.g., Cx. tarsalis) toward higher elevations in Colorado.
    Keywords insect ecology ; habitats ; piedmont ; mountains ; population ecology ; population distribution ; population size ; spatial variation ; topography ; altitude ; climatic zones ; insect surveys ; light traps ; species diversity ; Aedes vexans ; Culex pipiens ; Culex tarsalis ; risk assessment ; insect vectors ; West Nile virus ; climate change ; Colorado
    Language English
    Dates of publication 2008-07
    Size p. 800-811.
    Document type Article
    ZDB-ID 410635-0
    ISSN 0022-2585
    ISSN 0022-2585
    DOI 10.1603/0022-2585(2008)45[800:MSRCAA]2.0.CO;2
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Association of human immune response to Aedes aegypti salivary proteins with dengue disease severity.

    Machain-Williams, C / Mammen, M P / Zeidner, N S / Beaty, B J / Prenni, J E / Nisalak, A / Blair, C D

    Parasite immunology

    2011  Volume 34, Issue 1, Page(s) 15–22

    Abstract: Dengue viruses (DENV; family Flaviviridae, genus Flavivirus) are transmitted by Aedes aegypti mosquitoes and can cause dengue fever (DF), a relatively benign disease, or more severe dengue haemorrhagic fever (DHF). Arthropod saliva contains proteins ... ...

    Abstract Dengue viruses (DENV; family Flaviviridae, genus Flavivirus) are transmitted by Aedes aegypti mosquitoes and can cause dengue fever (DF), a relatively benign disease, or more severe dengue haemorrhagic fever (DHF). Arthropod saliva contains proteins delivered into the bite wound that can modulate the host haemostatic and immune responses to facilitate the intake of a blood meal. The potential effects on DENV infection of previous exposure to Ae. aegypti salivary proteins have not been investigated. We collected Ae. aegypti saliva, concentrated the proteins and fractionated them by nondenaturing polyacrylamide gel electrophoresis (PAGE). By the use of immunoblots, we analysed reactivity with the mosquito salivary proteins (MSP) of sera from 96 Thai children diagnosed with secondary DENV infections leading either to DF or DHF, or with no DENV infection, and found that different proportions of each patient group had serum antibodies reactive to specific Ae. aegypti salivary proteins. Our results suggest that prior exposure to MSP might play a role in the outcome of DENV infection in humans.
    MeSH term(s) Adolescent ; Adult ; Aedes/immunology ; Animals ; Child ; Child, Preschool ; Dengue/pathology ; Disease Vectors ; Electrophoresis, Polyacrylamide Gel ; Female ; Humans ; Immunoblotting ; Insect Proteins/immunology ; Insect Proteins/isolation & purification ; Male ; Salivary Proteins and Peptides/immunology ; Salivary Proteins and Peptides/isolation & purification ; Statistics as Topic ; Thailand ; Young Adult
    Chemical Substances Insect Proteins ; Salivary Proteins and Peptides
    Language English
    Publishing date 2011-10-12
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 424444-8
    ISSN 1365-3024 ; 0141-9838
    ISSN (online) 1365-3024
    ISSN 0141-9838
    DOI 10.1111/j.1365-3024.2011.01339.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Molecular strategies for interrupting arthropod-borne virus transmission by mosquitoes.

    Blair, C D / Adelman, Z N / Olson, K E

    Clinical microbiology reviews

    2000  Volume 13, Issue 4, Page(s) 651–661

    Abstract: Arthropod-borne virus (arbovirus) infections cause a number of emerging and resurgent human and veterinary infectious diseases. Traditional means of controlling arbovirus diseases include vaccination of susceptible vertebrates and mosquito control, but ... ...

    Abstract Arthropod-borne virus (arbovirus) infections cause a number of emerging and resurgent human and veterinary infectious diseases. Traditional means of controlling arbovirus diseases include vaccination of susceptible vertebrates and mosquito control, but in many cases these have been unavailable or ineffective, and so novel strategies for disease control are needed. One possibility is genetic manipulation of mosquito vectors to render them unable to transmit arboviruses. This review describes recent work to test the concept of pathogen-derived resistance in arthropods by expression of viral genes in mosquito cell cultures and mosquitoes. Sense and antisense genome sequences from La Crosse virus (LAC) (a member of the Bunyaviridae) and dengue viruses serotypes 1 to 4 (DEN-1 to DEN-4) (members of the Flaviviridae) were expressed in mosquito cells from double-subgenomic and replicon vectors based on Sindbis virus (a member of the Togaviridae). The cells were then challenged with homologous or related viruses. For LAC, expression of antisense sequences from the small (S) genome segment, particularly full-length antisense S RNA, effectively interfered with replication of challenge virus, whereas expression of either antisense or sense RNA from the medium (M) segment was completely ineffective in LAC inhibition. Expression of sense and antisense RNA derived from certain regions of the DEN genome also blocked homologous virus replication more effectively than did RNA from other regions. Other parameters of RNA-mediated interference have been defined, such as the time when replication is blocked and the minimum size of effector RNA. The mechanism of RNA inhibition has not been determined, although it resembles double-stranded RNA interference in other nonvertebrate systems. Prospects for application of molecular strategies to control arbovirus diseases are briefly reviewed.
    MeSH term(s) Animals ; Arbovirus Infections/prevention & control ; Arbovirus Infections/transmission ; Arboviruses/genetics ; Arboviruses/pathogenicity ; Arboviruses/physiology ; Culicidae/genetics ; Culicidae/virology ; Gene Expression ; Gene Transfer Techniques ; Genome, Viral ; Humans ; Insect Vectors/genetics ; Insect Vectors/virology ; RNA, Antisense/genetics ; RNA, Viral/genetics ; Viral Interference ; Viral Proteins/genetics ; Viral Proteins/metabolism ; Virus Replication
    Chemical Substances RNA, Antisense ; RNA, Viral ; Viral Proteins
    Language English
    Publishing date 2000-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S. ; Review
    ZDB-ID 645015-5
    ISSN 1098-6618 ; 0893-8512
    ISSN (online) 1098-6618
    ISSN 0893-8512
    DOI 10.1128/CMR.13.4.651
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Effect of La Crosse virus infection on insemination rates in female Aedes triseriatus (Diptera: Culicidae)

    Gabitzsch, E.S / Blair, C.D / Beaty, B.J

    Journal of medical entomology. 2006 Sept., v. 43, no. 5

    2006  

    Abstract: Aedes triseriatus (Say) (Diptera: Culicidae) females orally infected with La Crosse virus after ingesting an infectious bloodmeal were compared for mating efficiency with females that ingested a noninfectious bloodmeal. After 14-d extrinsic incubation to ...

    Abstract Aedes triseriatus (Say) (Diptera: Culicidae) females orally infected with La Crosse virus after ingesting an infectious bloodmeal were compared for mating efficiency with females that ingested a noninfectious bloodmeal. After 14-d extrinsic incubation to allow for dissemination of the infection, all females were offered a second noninfectious bloodmeal and were placed in cages with age-matched males for 5 d. After 6 d, insemination rates were determined by detection of sperm in the spermathecae. Insemination rates of the La Crosse virus-infected females were significantly greater than in uninfected females.
    Keywords Aedes triseriatus ; insect vectors ; California encephalitis virus ; infection ; mating behavior ; insemination
    Language English
    Dates of publication 2006-09
    Size p. 850-852.
    Document type Article
    ZDB-ID 410635-0
    ISSN 0022-2585
    ISSN 0022-2585
    DOI 10.1603/0022-2585(2006)43[850:EOLCVI]2.0.CO;2
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Entomological studies along the Colorado Front Range during a period of intense West Nile virus activity.

    Bolling, B G / Moore, C G / Anderson, S L / Blair, C D / Beaty, B J

    Journal of the American Mosquito Control Association

    2007  Volume 23, Issue 1, Page(s) 37–46

    Abstract: To better understand the ecology of West Nile virus transmission in Northern Colorado, field studies were conducted in Larimer and Weld counties from September 2003 through March 2005. During summer studies, 18,540 adult mosquitoes were collected using ... ...

    Abstract To better understand the ecology of West Nile virus transmission in Northern Colorado, field studies were conducted in Larimer and Weld counties from September 2003 through March 2005. During summer studies, 18,540 adult mosquitoes were collected using light traps and gravid traps. West Nile virus RNA was detected in 24 of the 2,140 mosquito pools tested throughout the study area in 2003 and 2004. Culex tarsalis had the highest minimum infection rate (MIR) in both 2003 (MIR = 34.48) and in 2004 (MIR = 8.74). During winter studies, 9,391 adult mosquitoes were collected by aspirator from various overwintering sites including bridges and storm drains. The most frequently collected species was Culex pipiens. West Nile virus was not detected in our overwintering collections. The relationship between spring adult emergence and temperature inside and outside overwintering sites is described. Species composition of collections as well as the spatial and temporal distribution of West Nile virus detections are presented.
    MeSH term(s) Animals ; Climate ; Colorado ; Culex/virology ; Female ; Population Density ; Seasons ; Time Factors ; West Nile Fever/transmission ; West Nile virus
    Language English
    Publishing date 2007-03
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 632618-3
    ISSN 8756-971X
    ISSN 8756-971X
    DOI 10.2987/8756-971X(2007)23[37:ESATCF]2.0.CO;2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Studies on overwintering of bluetongue viruses in insects

    White, D.M / Wilson, W.C / Blair, C.D / Beaty, B.J

    Journal of general virology. 2005 Feb., v. 86, pt. 2

    2005  

    Abstract: Bluetongue viruses (BTVs) are economically important arboviruses that affect sheep and cattle. The overwintering mechanism of BTVs in temperate climates has eluded researchers for many years. Many arboviruses overwinter in their invertebrate vectors. To ... ...

    Abstract Bluetongue viruses (BTVs) are economically important arboviruses that affect sheep and cattle. The overwintering mechanism of BTVs in temperate climates has eluded researchers for many years. Many arboviruses overwinter in their invertebrate vectors. To test the hypothesis that BTVs overwinter in their vertically infected insect vectors, Culicoides sonorensis larvae were collected from long-term study sites in northern Colorado, USA, and assayed for the presence of BTV RNA by nested RT-PCR. Sequences from BTV RNA segment 7 were detected in 30 % (17/56) of pools composed of larvae and pupae collected in 1998 and in 10 % (31/319) of pools composed of adults reared from larvae collected in 1996. BTV was not isolated from the insects. Additionally, Culicoides cell-culture lines derived from material collected at one of the sites, or derived from insect samples collected during a BTV outbreak, contained BTV RNA segment 7. In contrast, segment 2 RNA was detected at half the rate of segment 7 RNA in the field-collected larvae and was only detected in the Culicoides cell lines with one of two primer sets. These data suggest that BTVs could overwinter in the insect vector and that there is reduced expression of the outer capsid genes during persistent infection.
    Keywords Bluetongue virus ; overwintering ; insect vectors ; disease vectors ; Culicoides sonorensis ; larvae ; adult insects ; RNA ; nucleotide sequences ; gene expression ; coat proteins ; genes ; cell lines ; Culicoides variipennis ; Colorado
    Language English
    Dates of publication 2005-02
    Size p. 453-462.
    Document type Article
    ZDB-ID 219316-4
    ISSN 1465-2099 ; 0022-1317
    ISSN (online) 1465-2099
    ISSN 0022-1317
    DOI 10.1099/vir.0.80290-0
    Database NAL-Catalogue (AGRICOLA)

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  10. Article: La Crosse virus infection of Aedes triseriatus (Diptera: Culicidae) ovaries before dissemination of virus from the midgut.

    Chandler, L J / Blair, C D / Beaty, B J

    Journal of medical entomology

    1998  Volume 35, Issue 4, Page(s) 567–572

    Abstract: La Crosse (LAC) virus is efficiently transmitted transovarially by the mosquito Aedes triseriatus (Say). To determine the time course and tropisms of LAC virus infection of ovaries, immunofluorescent antibody staining, in situ hybridization, and reverse ... ...

    Abstract La Crosse (LAC) virus is efficiently transmitted transovarially by the mosquito Aedes triseriatus (Say). To determine the time course and tropisms of LAC virus infection of ovaries, immunofluorescent antibody staining, in situ hybridization, and reverse transcription-polymerase chain reaction techniques were used to detect viral antigen and RNA in the ovaries. LAC virus was detected in the ovaries (presumably in calyx tissues) by all 3 assays at day 2 after infection and before dissemination from the midgut on day 6. Apparently, ovaries can become infected by mechanisms other than by dissemination of virus from a midgut infection. By days 8-14 after infection, virus analytes became detectable in many tissues within the ovary including follicular epithelium, oocytes, nurse cells, and calyx, reflecting the remarkable host parasite relationship between LAC virus and its mosquito vector.
    MeSH term(s) Aedes/virology ; Animals ; Cells, Cultured ; Digestive System ; Female ; La Crosse virus/genetics ; Mice ; Ovary/virology ; Polymerase Chain Reaction ; RNA, Viral
    Chemical Substances RNA, Viral
    Language English
    Publishing date 1998-07
    Publishing country England
    Document type Journal Article ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 410635-0
    ISSN 0022-2585
    ISSN 0022-2585
    DOI 10.1093/jmedent/35.4.567
    Database MEDical Literature Analysis and Retrieval System OnLINE

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