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1.
PLoS One ; 19(4): e0301380, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38687736

RESUMEN

Globally, old urban neighborhood transformation has become a new urban sustainability focus for its significant contribution to the United Nation's Sustainable Development Goal 11. A regeneration-oriented approach is particularly important for Chinese cities with a dwindling land supply, obsoleting infrastructure, and inadequate standard of living. Using a mixed-methods approach informed by BREEAM Communities, we examined two Chinese initiatives-old urban neighborhood renewal (OUNR) and sponge city development (SCD)-through a comprehensive study of pilot project sustainability, policy emphases and gaps, and broader governance implications. We found that SCD's top-down technocratic management was highly efficient in enhancing neighborhood hydrological functions and physical environment. However, successes were undermined by the lack of climate considerations and civic participation. Besides actionable recommendations for applied scholarship and policymaking in China, we provide insight into how the OUNR/SCD initiatives may broadly inform worldwide urban regeneration practices through project and policy experimentations that build adaptive capacity.


Asunto(s)
Desarrollo Sostenible , Remodelación Urbana , China , Humanos , Características de la Residencia , Ciudades , Proyectos Piloto , Conservación de los Recursos Naturales/métodos , Planificación de Ciudades/métodos
2.
SN Soc Sci ; 2(12): 255, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36465091

RESUMEN

Many students find environmental justice to be emotionally overwhelming and/or politically alienating, and there is currently little work that provides instructors with effective techniques for addressing these types of challenges. In this paper, upon situating the environmental studies classroom and the broader undergraduate experience in sociohistorical context, we identify four sequential strategies for engaging and empowering students on environmental justice issues. First, instructors can facilitate an open and honest dialogue by strategically framing course content for the unique composition of the audience, sharing their own racialized experiences (or working with a guest speaker who would be willing to do so), and using interactive assignments to encourage student participation. Second, social theory can be presented to students as complimentary (rather than competing) ideas which can be used for creative, real-world problem solving. Third, instructors and students can cultivate empathy by acknowledging different standpoints, particularly those that have been historically marginalized. Lastly, by working in partnerships with community-based organizations, instructors and students can think and work beyond hero/savior and perpetrator/victim narratives. These strategies are not intended as a set of silver bullets, but rather as a series of potential starting points that are informed by recent scholarship on these topics.

3.
Environ Manage ; 69(3): 558-575, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35020029

RESUMEN

The Sponge City Development (SCD) concept was initiated in 2012 to address severe urban flooding and water quality challenges in China. Green stormwater infrastructure (GSI) such as rain gardens have been adopted as critical stormwater management tools. Existing GSI research has focused primarily on their environmental performance, overlooking the human dimensions. The co-benefits of GSI have been particularly underinvestigated. We used social surveys (n = 607) and expert interviews (n = 11) to explore public perception of SCD and GSI in four pilot sponge cities, examining flood experience, stormwater concerns, GSI familiarity, institutional trust, and GSI benefit perception. The survey found high exposure to flooding, medium GSI familiarity, and strong institutional trust. The public showed greater concern on stormwater impacts on their quality-of-life than the water environment, rating the less-intended aesthetic and health values as the best-perceived benefits. Experience, familiarity, concern, trust, age, and city significantly affected GSI benefit perception. In contrast, the experts spoke more positively about the environmental benefits while indicating the inadequacy of public participation. The case of GSI in SCD offers broad implications for environmental governance and expert-public relationships in an era of rapid social, technological, and environmental change. Refining policies and regulations to incorporate social goals, bringing the public into the SCD process, and building up the GSI industry's capacity in planning, design, construction, and maintenance are critical to enhancing GSI benefits provision. Adopting the co-benefits approach will be essential to utilizing GSI as a place-making tool to create more sustainable and livable communities.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Ciudades , Política Ambiental , Humanos , Lluvia
4.
J Soc Psychol ; 162(1): 161-177, 2022 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-35037571

RESUMEN

People appear to empathize with cases of animal suffering yet to disregard such suffering when it conflicts with human needs. In three studies, we used an empathy regulation measure - the empathy selection task - to test whether people choose or avoid sharing in experiences of animals versus humans. In Study 1, when choosing between sharing experiences of animals or humans, participants preferred humans and rated sharing animal (versus human) experiences as more cognitively costly. In Studies 2a-2b, the choice to share experiences or be objective was done without a forced choice between animals and humans. When empathy opportunities for humans and animals were not contrasted against each other, participants avoided experience sharing for humans but not for animals. Manipulations of prosocial cost in these studies did not consistently moderate choice differences. Freeing people from contexts that pit empathy for animals against empathy for humans may diminish motivated disregard of animals' experiences.


Asunto(s)
Conducta de Elección , Empatía , Animales , Humanos
6.
Agric Human Values ; 38(4): 943-961, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34456466

RESUMEN

The emergence of the "4th Industrial Revolution," i.e. the convergence of artificial intelligence, the Internet of Things, advanced materials, and bioengineering technologies, could accelerate socioeconomic insecurities and anxieties or provide beneficial alternatives to the status quo. In the post-Covid-19 era, the entities that are best positioned to capitalize on these innovations are large firms, which use digital platforms and big data to orchestrate vast ecosystems of users and extract market share across industry sectors. Nonetheless, these technologies also have the potential to democratize ownership, broaden political-economic participation, and reduce environmental harms. We articulate the potential sociotechnical pathways in this high-stakes crossroads by analyzing cellular agriculture, an exemplary 4th Industrial Revolution technology that synergizes computer science, biopharma, tissue engineering, and food science to grow cultured meat, dairy, and egg products from cultured cells and/or genetically modified yeast. Our exploration of this space involved multi-sited ethnographic research in both (a) the cellular agriculture community and (b) alternative economic organizations devoted to open source licensing, member-owned cooperatives, social financing, and platform business models. Upon discussing how these latter approaches could potentially facilitate alternative sociotechnical pathways in cellular agriculture, we reflect upon the broader implications of this work with respect to the 4th Industrial Revolution and the enduring need for public policy reform.

7.
Am J Trop Med Hyg ; 82(3): 501-4, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20207881

RESUMEN

An automated colorimetric micro-neutralization assay (CmNt) was developed for confirmation and differentiation of West Nile Virus (WNV)-positive human sera as a higher throughput alternative to the standard six-well plaque-reduction neutralization test (PRNT). CmNt was performed in high-capacity 96-well micro-titer plates and required 4-6 days to complete. Inhibition of infection was determined by reduced neutral red-dye retention and conveniently recorded by a colorimetric plate reader. Human sera previously confirmed by PRNT as either negative (N = 52), WNV positive (N = 81), or St. Louis encephalitis virus positive (N = 12) were tested by CmNt; interpreted results were virtually identical to PRNT with a reduced turnaround time and higher throughput. Additionally, a handful of dengue virus positive and negative specimens (four each) were tested by CmNt; interpreted results were identical to PRNT.


Asunto(s)
Colorimetría/métodos , Virus de la Encefalitis de San Luis/aislamiento & purificación , Pruebas de Neutralización/métodos , Virus del Nilo Occidental/aislamiento & purificación , Animales , Chlorocebus aethiops , Células Vero
8.
Am J Trop Med Hyg ; 78(3): 434-41, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18337340

RESUMEN

Adult domestic chickens were infected with West Nile virus (WNV) or St. Louis encephalitis virus (SLEV) and challenged with homologous or heterologous virus at 21 or 56 days postinfection (dpi). Sera were collected at selected time points after infection and assayed by enzyme immunoassay (EIA), plaque reduction neutralization test (PRNT), and a Western blot (WB) alternative to PRNT. EIA results were sensitive and accurate (few false positives) but not specific, requiring a confirmatory test to determine virus infection history. PRNT results generally were specific until challenge, after which test results were frequently equivocal and inadequate to determine first or second infecting virus. WB results confirmed the serologic cross-reactivity between WNV and SLEV envelope protein. Non-structural protein 1 and pre-membrane protein reactivities were highly specific for WNV during SLEV infection, but less specific for SLEV during WNV infection. WB and PRNT specificities were similar for both viruses from 6 to 14 dpi, and sensitivities to WNV were virtually identical.


Asunto(s)
Pollos , Encefalitis de San Luis/veterinaria , Enfermedades de las Aves de Corral/sangre , Fiebre del Nilo Occidental/veterinaria , Animales , Western Blotting/veterinaria , Virus de la Encefalitis de San Luis/aislamiento & purificación , Encefalitis de San Luis/sangre , Encefalitis de San Luis/diagnóstico , Femenino , Técnicas para Inmunoenzimas/veterinaria , Pruebas de Neutralización/veterinaria , Enfermedades de las Aves de Corral/diagnóstico , Enfermedades de las Aves de Corral/virología , Sensibilidad y Especificidad , Pruebas Serológicas/veterinaria , Factores de Tiempo , Viremia , Fiebre del Nilo Occidental/sangre , Fiebre del Nilo Occidental/diagnóstico , Virus del Nilo Occidental/aislamiento & purificación
9.
Am J Trop Med Hyg ; 77(1): 159-63, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17620648

RESUMEN

The spread of West Nile virus (WNV) across the United States into areas with endemic flavivirus activity has complicated serologic surveillance of seasonal virus activity and diagnosis of infected individuals. Here we describe preliminary results from a comparison of serologic assays for flaviviruses: the reference plaque reduction neutralization test (PRNT), enzyme immunoassay (EIA), and a Western blot (WB) in which crude viral lysates were electrophoresed and blotted onto nitrocellulose. Human and chicken sera were tested and compared by each method against WNV and St. Louis encephalitis virus (SLEV). Antibody binding to three viral proteins determined WB interpretation: non-structural protein 1 (NS1), envelope (E), and pre-membrane (prM). WB results for a group of serially collected human plasma samples from WNV seroconverting blood donors were also correlated with transcription mediated amplification (TMA) and polymerase chain reaction (RT-PCR) results. Reactivity with NS1 appeared to be the most useful differentiating marker of WNV and SLEV infection in humans and chickens. Envelope protein was highly cross-reactive and, as indicated by additional results from dengue virus (DENV)-positive human sera, is perhaps useful serologically as a flavivirus group antigen.


Asunto(s)
Western Blotting , Infecciones por Flavivirus/virología , Flavivirus/aislamiento & purificación , Animales , Anticuerpos Antivirales/análisis , Pollos , Ensayo de Inmunoadsorción Enzimática , Flavivirus/genética , Flavivirus/inmunología , Infecciones por Flavivirus/sangre , Humanos , Pruebas de Neutralización , Enfermedades de las Aves de Corral/sangre , Enfermedades de las Aves de Corral/virología , Valor Predictivo de las Pruebas , ARN Viral/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Pruebas Serológicas
10.
J Am Mosq Control Assoc ; 22(2): 272-81, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17019773

RESUMEN

The vector competence of Culex tarsalis Coquillett for the BFS 1703 strain of western equine encephalomyelitis virus (WEEV) changed significantly as a function of time after infection, mosquito genotype, and infectious virus dose. After ingesting a high virus dose (5 log10 plaque-forming units [PFU]/0.1 ml), female of the susceptible high virus producer (HVP) strain rapidly amplified the virus, developed a disseminated infection, and efficiently transmitted WEEV by 4 days postinfection (dpi). The quantity of virus expectorated peaked at 4 dpi (mean 3.4 log10 PFU), and the percentage of females transmitting per os peaked at 7 dpi (80%); both measures of transmission subsequently decreased to low levels throughout the remainder of infected life. HVP females imbibing a low virus dose (3 log10 PFU/0.1 ml) were infected less frequently and took longer to amplify virus to levels recorded for the high virus dose group and did not transmit virus efficiently, thereby indicating midgut infection and escape barriers were dose and time dependent. These data emphasized the importance of elevated avian viremias in Cx. tarsalis vector competence. Females from the WEEV-resistant (WR) strain and two wild-type strains from Kern and Riverside counties were significantly less susceptible to infection at both high and low doses than was the HVP strain. Overall, females with a high virus titer more frequently had a disseminated infection, but there did not seem to be a distinct threshold demarcating this relationship. In marked contrast, all infected females transmitting virus had body titers >4.3 log10 PFU, and most had titers >4.8 log10 PFU. These data indicated that not all females with a disseminated infection transmitted virus because of the presence of one or more salivary gland barriers.


Asunto(s)
Culex/virología , Virus de la Encefalitis Equina del Oeste/fisiología , Insectos Vectores/virología , Animales , Culex/genética , Encefalomielitis Equina/transmisión , Encefalomielitis Equina/virología , Femenino , Ratones , Factores de Tiempo
11.
J Am Mosq Control Assoc ; 20(3): 277-82, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15532927

RESUMEN

Female Culex tarsalis fed heparinized chicken blood-western equine encephalomyelitis virus (WEEV) mixtures through a biomembrane feeder were compared with females fed sweetened blood-virus mixtures presented in pledgets or as hanging drops or to restrained chickens with natural or artificial viremias. Results indicated that sodium heparin did not adversely affect the infection of Culex tarsalis with WEEV. Overall advantages of the biomembrane system included 1) increased blood feeding frequency, 2) control of the infectious virus dose, and 3) greater or similar infection rates and body titers to females taking blood meals from viremic chickens. Anesthetizing females with triethylamine for in vitro transmission assessment using the capillary tube method produced results similar to immobilization using cold or CO2 + cold. Our research provided insight into tools useful to investigate the infection and transmission of WEEV by Cx. tarsalis.


Asunto(s)
Culex/virología , Virus de la Encefalitis Equina del Oeste/fisiología , Insectos Vectores/virología , Animales , Pollos/parasitología , Femenino , Inmovilización
12.
J Med Entomol ; 41(5): 965-72, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15535629

RESUMEN

Nestling mourning doves and house finches produced elevated viremias after inoculation with 2-3 log10 plaque-forming units (PFU) of St Louis encephalitis (SLE) virus and infected 67 and 70% of Culex tarsalis Coquillett that engorged upon them, respectively. Mosquito infection rates as well as the quantity of virus produced after extrinsic incubation increased as a function of the quantity of virus ingested and peaked during days 3-5 postinoculation in mourning doves and days 2-4 in house finches. Only female Cx. tarsalis with body titers > or = 4.6 log10 PFU were capable of transmitting virus. Overall, 38% of females infected by feeding on mourning doves and 22% feeding on house finches were capable of transmission. The quantity of virus expectorated was variable, ranging from 0.8 to 3.4 log10 PFU and was greatest during periods when avian viremias were elevated. Our data indicated that nestling mourning doves and house finches were competent hosts for SLE virus and that the quantity of virus ingested from a viremic avian host varies during the course of the infection and determines transmission rates by the mosquito vector.


Asunto(s)
Columbidae/virología , Virus de la Encefalitis de San Luis/aislamiento & purificación , Encefalitis de San Luis/transmisión , Pinzones/virología , Animales , Humanos
13.
J Med Entomol ; 41(5): 978-81, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15535631

RESUMEN

House finches, Carpodacus mexicanus, were experimentally infected with high and standard doses of western equine encephalomyelitis virus (WEEV) or St. Louis encephalitis virus (SLEV) to determine whether high doses would produce an elevated viremia response and a high frequency of chronic infections. Finches inoculated with approximately100,000 plaque forming units (PFU) of WEEV or SLEV produced viremia and antibody responses similar to those in finches inoculated with approximately 100 PFU of WEEV or 1000 PFU of SLEV, the approximate quantities of virus expectorated by blood-feeding Culex tarsalis Coquillett. Infected finches were held through winter and then necropsied. Only one finch inoculated with the high dose of SLEV developed a chronic infection. Our data indicated that elevated infectious doses of virus may not increase the viremia level or the frequency of chronic infection in house finches.


Asunto(s)
Virus de la Encefalitis de San Luis/aislamiento & purificación , Virus de la Encefalitis Equina del Oeste/aislamiento & purificación , Encefalitis de San Luis/fisiopatología , Encefalomielitis Equina del Oeste/fisiopatología , Pinzones/virología , Viremia/fisiopatología , Animales , Secuencia de Bases , Cartilla de ADN , Virus de la Encefalitis de San Luis/genética , Virus de la Encefalitis Equina del Oeste/genética , Reacción en Cadena de la Polimerasa , Carga Viral
14.
J Med Entomol ; 41(5): 982-6, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15535632

RESUMEN

The life table attributes of Culex tarsalis Coquillett females infected experimentally by feeding on 4 and 6 log10 plaque-forming units (PFU) of western equine encephalomyelitis virus (WEEV) per milliliter of heparinized chicken blood were compared with an uninfected control group. Females continually were offered 10% sucrose and an oviposition substrate and daily a blood meal through a biomembrane feeder. Mortality (dead females) and fecundity (female eggs per female) were monitored daily until all females died. Overall, 94% of 198 females in the two virus-infected groups were positive for WEEV at death when tested by plaque assay; the average body virus titer at death did not differ between groups. WEEV infection significantly altered the life table characteristics of Cx. tarsalis. Life expectancy at infection in days (ex), reproductive effort in female eggs per female per generation (Ro), and generation time (T) in days for the infected cohorts were significantly lower than for the uninfected controls, whereas the reproductive rate (rc) in female eggs per female per day was higher for infected than uninfected cohorts. In agreement with the WEEV infection data that showed similar body titers, there were few differences between the life table parameters for the 4 and 6 log10 PFU treatment groups. Greatest differences were observed for survivorship between days 17-40 when virus titers in infected dying females were greatest. Our data extend recent studies that indicate mosquito infection with encephalitis viruses has a cost of reduced life expectancy and fitness.


Asunto(s)
Culex/virología , Virus de la Encefalitis Equina del Oeste/patogenicidad , Animales , Culex/crecimiento & desarrollo , Modelos Animales de Enfermedad , Virus de la Encefalitis Equina del Oeste/aislamiento & purificación , Femenino , Tablas de Vida , Oviposición , Reproducción
15.
Emerg Infect Dis ; 10(8): 1369-78, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15496236

RESUMEN

West Nile virus (WNV) was first isolated in California during July 2003 from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV transmission then increased and spread in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside to San Diego County. WNV was reported concurrently from Arizona in mid-August and from Baja, Mexico, in mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed.


Asunto(s)
Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/transmisión , Virus del Nilo Occidental , Animales , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Enfermedades de las Aves/virología , Aves/virología , California/epidemiología , Pollos/virología , Clima , Culex/virología , Vigilancia de Guardia , Fiebre del Nilo Occidental/veterinaria , Fiebre del Nilo Occidental/virología
16.
J Med Entomol ; 41(4): 539-44, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15311443

RESUMEN

A blinded laboratory evaluation compared the accuracy, sensitivity, and specificity of an in situ enzyme immunoassay (EIA), VecTest wicking assay, and reverse transcription-polymerase chain reaction (RT-PCR) to detect and distinguish West Nile (WN) and St. Louis encephalitis (SLE) viruses in pools of 50 mosquitoes. Adult female Culex tarsalis Coquillett were inoculated with either WN or SLE viruses, held for 0-11 d at 28 degrees C, killed by freezing, and then were added to 49 or 48 uninfected mosquitoes to make up 14 pools positive for WN virus, 14 positive for SLE virus, 14 positive for both WN and SLE viruses, and 14 negative for virus. Pools were number coded and tested blindly. Virus was not detected in known negative pools. VecTest and RT-PCR assays were comparably sensitive and accurate, detecting virus in pools containing females held for 3 d postinoculation; only RT-PCR detected SLE virus in pools on days 0-1. The VecTest and RT-PCR produced a single false-positive result for WN and SLE, respectively. RT-PCR detected RNA in samples positive by the VecTest, indicating that the detergent in the wicking buffer did not prevent RT-PCR from confirming VecTest results. Detector antibodies used in the in situ EIA cross-reacted between SLE and WN viruses, reducing accuracy. Both the VecTest and RT-PCR provided rapid and specific results, but they detected only those viruses known to be present. Plaque assay on Vero cells was comparably sensitive and had the added benefit of detecting newly emerging viruses, but this method required virus culture followed by identification, thereby delaying reporting.


Asunto(s)
Culex/virología , Virus de la Encefalitis de San Luis/aislamiento & purificación , Laboratorios/normas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Virus del Nilo Occidental/aislamiento & purificación , Animales , Virus de la Encefalitis de San Luis/genética , Femenino , Técnicas para Inmunoenzimas , Virología/métodos , Virus del Nilo Occidental/genética
17.
J Med Entomol ; 41(3): 462-6, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15185951

RESUMEN

After-hatching and hatching year, mourning doves were infected by inoculation with either western equine encephalomyelitis (WEE) or St. Louis encephalitis (SLE) viruses; some birds in each group also were treated with the immunosuppressant cyclophosphamide before and during infection. Cyclophosphamide treatment significantly increased the WEE viremia but did not alterthe antibody response. In contrast, cyclophosphamide-treated and -untreated doves did not develop a detectable SLE viremia but became antibody positive. Antibody peaked at 10 wk after inoculation for both viruses and remained detectable in most birds throughout the 26-wk study. When treated with cyclophosphamide the following spring, birds did not relapse and develop a detectable viremia. Previously infected birds were protected when challenged with conspecific virus (i.e., none produced a detectable viremia), but there was no anamnestic antibody response to reinfection. In agreement with our failure to detect relapses, all birds were negative for viral RNA when sera, spleen, lung, and kidney tissues were tested by reverse transcriptase-polymerase chain reaction after necropsy. Our results indicated that adult mourning doves were an incompetent host for SLE virus and probably do not serve as a suitable overwintering or dispersal host for either WEE and SLE viruses.


Asunto(s)
Columbidae/virología , Virus de la Encefalitis de San Luis/aislamiento & purificación , Virus de la Encefalitis Equina del Oeste/aislamiento & purificación , Animales , Anticuerpos Antivirales/análisis , Enfermedades de las Aves/virología , California , Ciclofosfamida/farmacología , Virus de la Encefalitis de San Luis/efectos de los fármacos , Virus de la Encefalitis Equina del Oeste/efectos de los fármacos , Encefalitis de San Luis/prevención & control , Encefalitis de San Luis/transmisión , Encefalomielitis Equina/prevención & control , Encefalomielitis Equina/transmisión , Inmunosupresores/farmacología , Viremia/veterinaria
18.
Comp Immunol Microbiol Infect Dis ; 27(3): 209-15, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15001316

RESUMEN

Jamestown Canyon (JC) and Saint Louis encephalitis (SLE) viruses are mosquito-transmitted viruses that have long been present in California. The objective of this study was to determine the seroprevalence of these two viruses in horses prior to the introduction of West Nile (WN) virus. Approximately 15% of serum samples collected in 1998 from 425 horses on 44 equine operations horses throughout California had serum antibodies to JC virus, whereas antibodies were not detected to SLE virus. The results indicate that horses in California were commonly infected prior to 1998 with mosquito-transmitted Bunyaviruses that are identical or closely related to JC virus, but not with SLE virus. The different seroprevalence of SLE and JC viruses in horses likely reflects the unique ecology of each virus, and it is predicted that WN virus will have a wider distribution in California than closely related SLE virus.


Asunto(s)
Anticuerpos Antivirales/sangre , Virus de la Encefalitis de California/inmunología , Virus de la Encefalitis de San Luis/inmunología , Encefalitis de San Luis/veterinaria , Enfermedades de los Caballos/virología , Infecciones por Polyomavirus/veterinaria , Infecciones Tumorales por Virus/veterinaria , Animales , California/epidemiología , Virus de la Encefalitis de California/aislamiento & purificación , Virus de la Encefalitis de San Luis/aislamiento & purificación , Encefalitis de San Luis/epidemiología , Encefalitis de San Luis/inmunología , Encefalitis de San Luis/virología , Femenino , Enfermedades de los Caballos/epidemiología , Enfermedades de los Caballos/inmunología , Caballos , Modelos Logísticos , Masculino , Pruebas de Neutralización/veterinaria , Infecciones por Polyomavirus/epidemiología , Infecciones por Polyomavirus/inmunología , Infecciones por Polyomavirus/virología , Estudios Seroepidemiológicos , Encuestas y Cuestionarios , Infecciones Tumorales por Virus/epidemiología , Infecciones Tumorales por Virus/inmunología , Infecciones Tumorales por Virus/virología
19.
J Med Entomol ; 40(2): 206-14, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12693850

RESUMEN

Immunosuppression of house finches was attempted by blood feeding Culex tarsalis Coquillett mosquitoes or by injecting birds with the corticosteroid dexamethasone or the immunosuppressant drug cyclophosphamide before and after inoculation with western equine encephalomyelitis or St. Louis encephalitis viruses. Mosquito bites (8-37 females blood feeding on each bird over a 3-d period) did not enhance the viremia response or increase the frequency of chronic infection. In contrast, dexamethasone and cyclophosphamide enhanced the amplitude and duration of the viremia response, but had no consistent effect on the antibody responses as measured by enzyme immunoassay or plaque reduction neutralization assay. Elevated viremias were followed by increases in the frequency of chronic infections with St. Louis encephalitis, but not western equine encephalomyelitis. Immunosuppression may provide a useful tool to study the chronic infection process of flaviviruses in vertebrates.


Asunto(s)
Enfermedades de las Aves/virología , Culex/virología , Virus de la Encefalitis/aislamiento & purificación , Encefalitis/veterinaria , Pájaros Cantores/inmunología , Pájaros Cantores/virología , Animales , Enfermedades de las Aves/inmunología , Enfermedades de las Aves/prevención & control , Cartilla de ADN , Encefalitis/inmunología , Encefalitis/prevención & control , Virus de la Encefalitis/genética , Virus de la Encefalitis/inmunología , Femenino , Terapia de Inmunosupresión/métodos , Masculino , Reacción en Cadena de la Polimerasa , Viremia/inmunología , Viremia/prevención & control , Viremia/veterinaria
20.
J Med Entomol ; 39(1): 226-33, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11931262

RESUMEN

Female Culex tarsalis Coquillett in reproductive diapause were infected per os or by intrathoracic inoculation with western equine encephalomyelitis (WEE) or St. Louis encephalitis (SLE) viruses during "fall," maintained over a simulated "winter," and then tested for virus infection and transmission in vitro and in vivo after "vernal" termination. Exposure of F1 progeny of field-collected females to cool temperatures and short daylength produced females in reproductive diapause that were reluctant to imbibe infectious virus from pledgets soaked with suspensions of virus, blood and sucrose (2.5% by volume). Those infected per os maintained virus at very low or undetectable titers. Some females that originally tested negative for WEE by plaque assay on Vero cell culture tested positive by reverse transcriptase-polymerase chain reaction (RT-PCR) and by Vero cell culture after passage in mosquito cells. Few females became infected orally with SLE, but these infected females developed elevated titers. Females inoculated with SLE retained their infection through winter and then transmitted readily in vitro and in vivo. Feeding on a vertebrate host after diapause termination significantly increased the titer of SLE in previously infected females. These experiments simulated how infections acquired either horizontally or vertically may provide mechanisms for WEE and SLE overwintering. Attempts to detect infected females during winter following a summer with enzootic WEE activity were negative by both RT-PCR and plaque assay.


Asunto(s)
Culex/virología , Virus de la Encefalitis de San Luis/fisiología , Virus de la Encefalitis Equina del Oeste/fisiología , Insectos Vectores/virología , Animales , Culex/fisiología , Virus de la Encefalitis de San Luis/genética , Virus de la Encefalitis Equina del Oeste/genética , Femenino , Insectos Vectores/fisiología , Estaciones del Año
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