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1.
Rapid Commun Mass Spectrom ; 34(18): e8851, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-32492222

RESUMEN

RATIONALE: The presence of lipids in animal tissues can influence the interpretation of stable isotope data, particularly in lipid-rich tissues such as the skin and muscle of marine mammals. The traditionally employed chloroform-methanol delipidation protocol has the potential to alter δ15 N values in proteinaceous tissues. Our objective was to determine whether the use of cyclohexane could be an alternative extraction method, effectively removing lipids without altering δ15 N values. METHODS: Kidney, liver, muscle, and skin samples were collected from beach-cast Sowerby's beaked whales (Mesoplodon bidens). Control subsamples were processed without delipidation extraction, and duplicate subsamples were extracted with either chloroform-methanol or cyclohexane. δ13 C, δ15 N, and C:N values were determined by continuous-flow elemental analysis isotope ratio mass spectrometry. Paired Wilcoxon tests were used to evaluate the change in isotope ratios after extraction, and unpaired Wilcoxon tests were used to evaluate differences in isotope ratios between extractions. RESULTS: Use of cyclohexane is an effective delipidation technique for tissues with low and moderate lipid content. Chemical delipidation influenced δ15 N values; extracted samples generally showed an increase in δ15 N values which varied from 0.0‰ to 1.7‰. Chloroform-methanol extraction resulted in alterations to δ15 N values greater than the analytical precision for all analyzed tissues. Changes to δ15 N values after cyclohexane extraction were at or near the analytical precision for liver and muscle but greater than the analytical precision for kidney and skin. CONCLUSIONS: We recommend processing duplicate subsamples for stable isotope analysis, one with and one without extraction, in order to obtain accurate values for each isotope ratio. Prolonged chemical extractions are not necessary to effectively remove lipids. When samples are limited, we suggest using cyclohexane for tissues with low or moderate lipid content, and chloroform-methanol for lipid-rich tissues.


Asunto(s)
Isótopos de Carbono/análisis , Fraccionamiento Químico/métodos , Lípidos/aislamiento & purificación , Isótopos de Nitrógeno/análisis , Ballenas/fisiología , Animales , Cloroformo/química , Ciclohexanos/química , Riñón/química , Hígado/química , Espectrometría de Masas , Metanol/química , Escocia
2.
Ecol Evol ; 9(4): 1603-1622, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30847059

RESUMEN

Anthropogenic climate change is widely considered a major threat to global biodiversity, such that the ability of a species to adapt will determine its likelihood of survival. Egg-burying reptiles that exhibit temperature-dependent sex determination, such as critically endangered hawksbill turtles (Eretmochelys imbricata), are particularly vulnerable to changes in thermal regimes because nest temperatures affect offspring sex, fitness, and survival. It is unclear whether hawksbills possess sufficient behavioral plasticity of nesting traits (i.e., redistribution of nesting range, shift in nesting phenology, changes in nest-site selection, and adjustment of nest depth) to persist within their climatic niche or whether accelerated changes in thermal conditions of nesting beaches will outpace phenotypic adaption and require human intervention. For these reasons, we estimated sex ratios and physical condition of hatchling hawksbills under natural and manipulated conditions and generated and analyzed thermal profiles of hawksbill nest environments within highly threatened mangrove ecosystems at Bahía de Jiquilisco, El Salvador, and Estero Padre Ramos, Nicaragua. Hawksbill clutches protected in situ at both sites incubated at higher temperatures, yielded lower hatching success, produced a higher percentage of female hatchlings, and produced less fit offspring than clutches relocated to hatcheries. We detected cooler sand temperatures in woody vegetation (i.e., coastal forest and small-scale plantations of fruit trees) and hatcheries than in other monitored nest environments, with higher temperatures at the deeper depth. Our findings indicate that mangrove ecosystems present a number of biophysical (e.g., insular nesting beaches and shallow water table) and human-induced (e.g., physical barriers and deforestation) constraints that, when coupled with the unique life history of hawksbills in this region, may limit behavioral compensatory responses by the species to projected temperature increases at nesting beaches. We contend that egg relocation can contribute significantly to recovery efforts in a changing climate under appropriate circumstances.

3.
PeerJ ; 5: e3709, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28828282

RESUMEN

Ecologists have long recognized the influence that environmental conditions have on abundance and range extent of animal species. We used the northern bobwhite (Colinus virginianus; hereafter bobwhite) as a model species for studying how microclimates serve as refuge against severe weather conditions. This species serves as an indicator or umbrella species for other sensitive ground-nesting, grassland obligate species. We conducted a mensurative field experiment in the rolling plains of Texas, USA, a semi-arid ecosystem on the southwestern periphery of bobwhite range, to determine whether native bunch grasses, apparently suitable for bobwhite nesting, could reduce ambient temperature below levels harmful for eggs. During the nesting season, we compared temperature and relative humidity readings at daily heat maxima (i.e., the 3 h during each day with highest temperatures) during the nesting season over the course of two years at 63 suitable nest sites paired with 63 random locations (n = 126) using two sensors at ∼10 and ∼60 cm above ground level. Mean temperature at nest height was 2.3% cooler at nest sites (35.99 °C ± 0.07 SE) compared to random locations (36.81 °C ± 0.07 SE); at ambient height, nest sites were slightly cooler (32.78 °C ± 0.06 SE) than random location (32.99 °C ± 0.06 SE). Mean relative humidity at nest sites was greater at nest height (34.53% ± 0.112 SE) and ambient height (36.22% ± 0.10 SE) compared to random locations at nest (33.35% ± 0.12 SE) and ambient height (35.75% ± 0.10 SE). Based on these results, cover at sites that appear visually suitable for nesting by bobwhites and other ground nesting birds provided adequate thermal refuge in the rolling plains by maintaining cooler, moister microclimates than surrounding non-nesting locations. Post-hoc analyses of data revealed that habitat conditions surrounding suitable nest sites strongly influenced thermal suitability of the substrate. Given that eggs of bobwhites and probably other species would experience lethal temperatures without these thermal refuges in the context of proper habitat condition, nesting vegetation is a critical component of niche space for bobwhites and other ground nesting birds in semi-arid regions. Many contemporary land uses, however, degrade or destroy bunch grasses and grassland systems, and thus decrease landscape inhabitability. Conservationists working with obligate grassland species that require bunch grasses in semi-arid regions should develop land management strategies that maximize the availability of these thermal refuges across space and time.

4.
G3 (Bethesda) ; 7(9): 3047-3058, 2017 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-28717047

RESUMEN

Northern bobwhite (Colinus virginianus; hereafter bobwhite) and scaled quail (Callipepla squamata) populations have suffered precipitous declines across most of their US ranges. Illumina-based first- (v1.0) and second- (v2.0) generation draft genome assemblies for the scaled quail and the bobwhite produced N50 scaffold sizes of 1.035 and 2.042 Mb, thereby producing a 45-fold improvement in contiguity over the existing bobwhite assembly, and ≥90% of the assembled genomes were captured within 1313 and 8990 scaffolds, respectively. The scaled quail assembly (v1.0 = 1.045 Gb) was ∼20% smaller than the bobwhite (v2.0 = 1.254 Gb), which was supported by kmer-based estimates of genome size. Nevertheless, estimates of GC content (41.72%; 42.66%), genome-wide repetitive content (10.40%; 10.43%), and MAKER-predicted protein coding genes (17,131; 17,165) were similar for the scaled quail (v1.0) and bobwhite (v2.0) assemblies, respectively. BUSCO analyses utilizing 3023 single-copy orthologs revealed a high level of assembly completeness for the scaled quail (v1.0; 84.8%) and the bobwhite (v2.0; 82.5%), as verified by comparison with well-established avian genomes. We also detected 273 putative segmental duplications in the scaled quail genome (v1.0), and 711 in the bobwhite genome (v2.0), including some that were shared among both species. Autosomal variant prediction revealed ∼2.48 and 4.17 heterozygous variants per kilobase within the scaled quail (v1.0) and bobwhite (v2.0) genomes, respectively, and estimates of historic effective population size were uniformly higher for the bobwhite across all time points in a coalescent model. However, large-scale declines were predicted for both species beginning ∼15-20 KYA.


Asunto(s)
Colinus/genética , Evolución Molecular , Variación Genética , Genoma , Genómica , Codorniz/genética , Animales , Biología Computacional/métodos , Variaciones en el Número de Copia de ADN , Bases de Datos de Ácidos Nucleicos , Duplicación de Gen , Genómica/métodos , Anotación de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Densidad de Población , Eliminación de Secuencia , Secuenciación Completa del Genoma
5.
J Eukaryot Microbiol ; 64(1): 4-17, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27222431

RESUMEN

We developed nested PCR protocols and performed a multiyear survey on the prevalence of several protozoan parasites in wild northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) in the Rolling Plains ecoregion of Texas and Oklahoma (i.e. fecal pellets, bird intestines and blood smears collected between 2010 and 2013). Coccidia, cryptosporidia, and microsporidia were detected in 46.2%, 11.7%, and 44.0% of the samples (n = 687), whereas histomona and hematozoa were undetected. Coccidia consisted of one major and two minor Eimeria species. Cryptosporidia were represented by a major unknown Cryptosporidium species and Cryptosporidium baileyi. Detected microsporidia species were highly diverse, in which only 11% were native avian parasites including Encephalitozoon hellem and Encephalitozoon cuniculi, whereas 33% were closely related to species from insects (e.g. Antonospora, Liebermannia, and Sporanauta). This survey suggests that coccidia infections are a significant risk factor in the health of wild quail while cryptosporidia and microsporidia may be much less significant than coccidiosis. In addition, the presence of E. hellem and E. cuniculi (known to cause opportunistic infections in humans) suggests that wild quail could serve as a reservoir for human microsporidian pathogens, and individuals with compromised or weakened immunity should probably take precautions while directly handling wild quail.


Asunto(s)
Enfermedades de las Aves/parasitología , Coccidios/aislamiento & purificación , Cryptosporidium/aislamiento & purificación , Microsporidios/aislamiento & purificación , Microsporidiosis/veterinaria , Infecciones Protozoarias en Animales/parasitología , Codorniz/parasitología , Trichomonadida/aislamiento & purificación , Tritrichomonas/aislamiento & purificación , Animales , Enfermedades de las Aves/epidemiología , Coccidios/genética , Colinus/parasitología , Criptosporidiosis/epidemiología , Criptosporidiosis/parasitología , Cryptosporidium/genética , ADN Protozoario/análisis , ADN Protozoario/genética , Heces/parasitología , Femenino , Masculino , Microsporidios/genética , Microsporidiosis/epidemiología , Microsporidiosis/parasitología , Oklahoma/epidemiología , Reacción en Cadena de la Polimerasa/métodos , Infecciones Protozoarias en Animales/diagnóstico , Infecciones Protozoarias en Animales/epidemiología , Codorniz/sangre , Factores de Riesgo , Encuestas y Cuestionarios , Texas/epidemiología , Trichomonadida/genética , Tritrichomonas/genética
6.
PLoS One ; 11(1): e0147517, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26816214

RESUMEN

Illegal wildlife-pet trade can threaten wildlife populations directly from overharvest, but also indirectly as a pathway for introduction of infectious diseases. This study evaluated consequences of a hypothetical introduction of Newcastle disease (ND) into a wild population of Peru's most trafficked psittacine, the white-winged parakeet (Brotogeris versicolurus), through release of infected confiscated individuals. We developed two mathematical models that describe ND transmission and the influence of illegal harvest in a homogeneous (model 1) and age-structured population of parakeets (model 2). Infection transmission dynamics and harvest were consistent for all individuals in model 1, which rendered it mathematically more tractable compared to the more complex, age-structured model 2 that separated the host population into juveniles and adults. We evaluated the interaction of ND transmission and harvest through changes in the basic reproduction number (R0) and short-term host population dynamics. Our findings demonstrated that ND introduction would likely provoke considerable disease-related mortality, up to 24% population decline in two years, but high harvest rates would dampen the magnitude of the outbreak. Model 2 produced moderate differences in disease dynamics compared to model 1 (R0 = 3.63 and 2.66, respectively), but highlighted the importance of adult disease dynamics in diminishing the epidemic potential. Therefore, we suggest that future studies should use a more realistic, age-structured model. Finally, for the presumptive risk that illegal trade of white-winged parakeets could introduce ND into wild populations, our results suggest that while high harvest rates may have a protective effect on the population by reducing virus transmission, the combined effects of high harvest and disease-induced mortality may threaten population survival. These results capture the complexity and consequences of the interaction between ND transmission and harvest in a wild parrot population and highlight the importance of preventing illegal trade.


Asunto(s)
Animales Salvajes/virología , Enfermedades de las Aves/epidemiología , Modelos Teóricos , Enfermedad de Newcastle/epidemiología , Periquitos/virología , Animales , Número Básico de Reproducción , Enfermedades de las Aves/transmisión , Enfermedades de las Aves/virología , Brotes de Enfermedades , Enfermedad de Newcastle/transmisión , Enfermedad de Newcastle/virología , Perú , Dinámica Poblacional
7.
Conserv Biol ; 30(1): 23-32, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26041036

RESUMEN

Conservation policy sits at the nexus of natural science and politics. On the one hand, conservation scientists strive to maintain scientific credibility by emphasizing that their research findings are the result of disinterested observations of reality. On the other hand, conservation scientists are committed to conservation even if they do not advocate a particular policy. The professional conservation literature offers guidance on negotiating the relationship between scientific objectivity and political advocacy without damaging conservation science's credibility. The value of this guidance, however, may be restricted by limited recognition of credibility's multidimensionality and emergent nature: it emerges through perceptions of expertise, goodwill, and trustworthiness. We used content analysis of the literature to determine how credibility is framed in conservation science as it relates to apparent contradictions between science and advocacy. Credibility typically was framed as a static entity lacking dimensionality. Authors identified expertise or trustworthiness as important, but rarely mentioned goodwill. They usually did not identify expertise, goodwill, or trustworthiness as dimensions of credibility or recognize interactions among these 3 dimensions of credibility. This oversimplification may limit the ability of conservation scientists to contribute to biodiversity conservation. Accounting for the emergent quality and multidimensionality of credibility should enable conservation scientists to advance biodiversity conservation more effectively.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Política Ambiental , Política , Biodiversidad
8.
PLoS One ; 10(12): e0144913, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26713762

RESUMEN

Herein, we evaluated the concordance of population inferences and conclusions resulting from the analysis of short mitochondrial fragments (i.e., partial or complete D-Loop nucleotide sequences) versus complete mitogenome sequences for 53 bobwhites representing six ecoregions across TX and OK (USA). Median joining (MJ) haplotype networks demonstrated that analyses performed using small mitochondrial fragments were insufficient for estimating the true (i.e., complete) mitogenome haplotype structure, corresponding levels of divergence, and maternal population history of our samples. Notably, discordant demographic inferences were observed when mismatch distributions of partial (i.e., partial D-Loop) versus complete mitogenome sequences were compared, with the reduction in mitochondrial genomic information content observed to encourage spurious inferences in our samples. A probabilistic approach to variant prediction for the complete bobwhite mitogenomes revealed 344 segregating sites corresponding to 347 total mutations, including 49 putative nonsynonymous single nucleotide variants (SNVs) distributed across 12 protein coding genes. Evidence of gross heteroplasmy was observed for 13 bobwhites, with 10 of the 13 heteroplasmies involving one moderate to high frequency SNV. Haplotype network and phylogenetic analyses for the complete bobwhite mitogenome sequences revealed two divergent maternal lineages (dXY = 0.00731; FST = 0.849; P < 0.05), thereby supporting the potential for two putative subspecies. However, the diverged lineage (n = 103 variants) almost exclusively involved bobwhites geographically classified as Colinus virginianus texanus, which is discordant with the expectations of previous geographic subspecies designations. Tests of adaptive evolution for functional divergence (MKT), frequency distribution tests (D, FS) and phylogenetic analyses (RAxML) provide no evidence for positive selection or hybridization with the sympatric scaled quail (Callipepla squamata) as being explanatory factors for the two bobwhite maternal lineages observed. Instead, our analyses support the supposition that two diverged maternal lineages have survived from pre-expansion to post-expansion population(s), with the segregation of some slightly deleterious nonsynonymous mutations.


Asunto(s)
Mitocondrias/genética , Animales , Colinus , Evolución Molecular , Femenino , Frecuencia de los Genes , Especiación Genética , Genoma Mitocondrial , Haplotipos , Masculino , Metagenómica , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADN
9.
PLoS One ; 9(3): e90240, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24621616

RESUMEN

Wild populations of northern bobwhites (Colinus virginianus; hereafter bobwhite) have declined across nearly all of their U.S. range, and despite their importance as an experimental wildlife model for ecotoxicology studies, no bobwhite draft genome assembly currently exists. Herein, we present a bobwhite draft de novo genome assembly with annotation, comparative analyses including genome-wide analyses of divergence with the chicken (Gallus gallus) and zebra finch (Taeniopygia guttata) genomes, and coalescent modeling to reconstruct the demographic history of the bobwhite for comparison to other birds currently in decline (i.e., scarlet macaw; Ara macao). More than 90% of the assembled bobwhite genome was captured within <40,000 final scaffolds (N50 = 45.4 Kb) despite evidence for approximately 3.22 heterozygous polymorphisms per Kb, and three annotation analyses produced evidence for >14,000 unique genes and proteins. Bobwhite analyses of divergence with the chicken and zebra finch genomes revealed many extremely conserved gene sequences, and evidence for lineage-specific divergence of noncoding regions. Coalescent models for reconstructing the demographic history of the bobwhite and the scarlet macaw provided evidence for population bottlenecks which were temporally coincident with human colonization of the New World, the late Pleistocene collapse of the megafauna, and the last glacial maximum. Demographic trends predicted for the bobwhite and the scarlet macaw also were concordant with how opposing natural selection strategies (i.e., skewness in the r-/K-selection continuum) would be expected to shape genome diversity and the effective population sizes in these species, which is directly relevant to future conservation efforts.


Asunto(s)
Colinus/genética , Genómica , Fenómenos Geológicos , Animales , Simulación por Computador , Evolución Molecular , Femenino , Humanos , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Mutación , Densidad de Población , Secuencias Repetitivas de Ácidos Nucleicos
10.
J Zoo Wildl Med ; 43(1): 168-70, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22448526

RESUMEN

The objective of this study was to evaluate the mottled duck (Anas fulvigula), a nonmigratory dabbling duck, as a sentinel species for avian influenza virus (AIV) surveillance. A total of 235 cloacal swabs from 147 live-captured and 88 hunter-harvested mottled ducks during summer (June-August 2007) and winter (November 2007 to January 2008), respectively, were collected along the upper Texas coast. Samples were screened for AIV using real-time reverse transcription polymerase chain reaction (rRT-PCR); all rRT-PCR-positive samples were processed for virus isolation. Three samples were positive for AIV by AIV-matrix rRT-PCR. One of these samples also was positive for H5 by rRT-PCR, and a low pathogenic H5N2 AIV was isolated. Although isolation of AIVs from mottled ducks during the winter has been reported previously, to the authors' knowledge, this is the first H5 isolate from mottled ducks. Interestingly, this isolation was made during the same season that other H5N2 viruses were obtained from migratory waterfowl on the Texas coast, which suggests AIV transmission among waterfowl on the wintering grounds and the potential role of mottled ducks as a naturally occurring sentinel species for AIV surveillance.


Asunto(s)
Patos , Gripe Aviar/epidemiología , Vigilancia de Guardia/veterinaria , Migración Animal , Animales , Femenino , Subtipo H5N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Masculino , Estudios Seroepidemiológicos , Texas/epidemiología
11.
Avian Dis ; 56(4 Suppl): 1006-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23402127

RESUMEN

Wild waterfowl are considered the natural reservoir of type A influenza viruses, and the migratory nature of many waterfowl species presents a possible vehicle for global dissemination of these infectious agents. In order to fully understand the ecology of influenza viruses, multiyear surveillance efforts are critical, particularly in understudied areas, such as waterfowl wintering areas. Herein we report results obtained during the fifth year ofa 5-yr avian influenza virus (AIV) surveillance project conducted on waterfowl wintering grounds of the Texas Coast. During year 5, the 2009-2010 hunting season (September, November-January), 655 cloacal swabs were collected from hunter-harvested waterfowl and screened for AIV by real-time RT-PCR (rRT-PCR) followed by virus isolation on all positive samples. Molecular methods were used for subtyping all AIV isolates. Sixty-five (9.5%) samples were positive for AIV by rRT-PCR, and 24 (3.7%) AIVs were isolated. Eight different hemagglutinin (H3, 4, 5, 6, 8, 9, 10, and 11) and seven different neuraminidase (N1, 2, 3, 4, 6, 8, and 9) subtypes were identified. This was the first year H8 and H9 were isolated throughout the 5-yr survey. Our results support the fact that continued multiyear surveillance of natural reservoirs, particularly in understudied areas, is needed in order to better understand the ecology of AIVs in nature.


Asunto(s)
Anseriformes , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Animales , Gripe Aviar/virología , Vigilancia de la Población , Texas/epidemiología , Factores de Tiempo
12.
J Wildl Dis ; 47(3): 784-6, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21719854

RESUMEN

Ninety-eight Green-winged Teal (Anas crecca) and 84 Northern Shoveler (Anas clypeata) gizzards were examined for ingested shot. One Northern Shoveler had lead and three had steel shot; 24 teal and 17 shovelers had composite nontoxic shot or nonlead metal fragments. Prevalence of ingested lead appears minimal and consistent with other studies conducted after lead-shot bans.


Asunto(s)
Enfermedades de las Aves/epidemiología , Patos , Intoxicación por Plomo/veterinaria , Plomo/análisis , Animales , Patos/metabolismo , Intoxicación por Plomo/epidemiología , Texas/epidemiología
13.
J Parasitol Res ; 2011: 306257, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21584230

RESUMEN

The influence of spatially distinct host subpopulations on helminth community structure and pattern was examined in a migratory avian host species. Forty helminth species represented by 24,082 individuals were collected from 184 blue-winged teal (Anas discors; BWT) from 2 primary migratory corridors in Florida (eastern migratory corridor; EMC) and Louisiana and Texas (western migratory corridor; WMC). Mean species richness was greater in BWT from the WMC (x̅±SE = 10.2 ± 0.3 species) than the EMC (8.6 ± 0.2). The helminth community from the WMC had higher abundances of 6 common/intermediate species. Corridor helminth communities were similar in species composition but less similar when incorporating abundances of those species. Overlapping distributions of phylogenetically related host species that share generalist helminth species across ecologically similar habitats seem to mitigate the isolating mechanisms that are necessary for the distinct coevolutionary pathways to develop between adjacent corridors.

14.
J Parasitol ; 97(4): 671-5, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21506827

RESUMEN

The Attwater's prairie chicken (APC; Tympanuchus cupido attwateri Bendire, 1894) has been a federally listed endangered species since 1967. Several captive propagation programs consisting of small populations are being used to keep this species from extinction. Fecal samples were collected from APCs in April 2007 and again in August 2008 from 2 separate captive propagation facilities in Texas after clinical signs of coccidiosis were observed. One Eimeria species was observed (Eimeria attwateri), which we describe as a putative new species. Sporulated oocysts are ellipsoidal, 30.0 × 18.4 (27.4-31.3 × 16.0-22.4) µm. Oocysts have a smooth wall 0.7 µm thick and lack both a micropyle and oocyst residuum, but 1 ellipsoidal polar granule is present, 2.3 × 1.9 (2.1-2.4 × 1.7-2.0) µm. Sporocysts have a nipple-like Stieda body with a rounded opposite end and are 14.0 × 7.1 (10.2-16.8 × 6.0-9.2) µm. The sporocysts contain a sporocyst residuum usually consisting of 2-4 dispersed globules, and each sporozoite contains 2 large posterior spheroid refractile bodies 3.4 µm wide. Nucleotide sequence amplified from the 18S rDNA does not match any DNA sequence information for publicly available Eimeria species, and phylogenetic reconstructions place this species with other eimerians from Galliformes. The discovery of a potentially pathogenic species of Eimeria in captive APCs is of great importance, and managers should be aware of the potential devastating effect(s) this parasite could have on the APC conservation programs.


Asunto(s)
Enfermedades de las Aves/parasitología , Coccidiosis/veterinaria , Eimeria/clasificación , Galliformes/parasitología , Animales , Teorema de Bayes , Coccidiosis/parasitología , ADN Protozoario/química , ADN Ribosómico/química , Eimeria/genética , Eimeria/ultraestructura , Especies en Peligro de Extinción , Heces/parasitología , Funciones de Verosimilitud , Microscopía de Interferencia , Datos de Secuencia Molecular , Oocistos/ultraestructura , Filogenia , ARN Ribosómico 18S/genética , Texas
15.
Emerg Infect Dis ; 16(8): 1224-30, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20678315

RESUMEN

We studied the prevalence of influenza A virus in wintering waterfowl from the Central Flyway on the Gulf Coast of Texas. Of 5,363 hunter-harvested migratory and resident waterfowl and wetland-associated game birds sampled during 3 consecutive hunting seasons (September-January 2006-07, 2007-08, and 2008-09), real-time reverse transcription-PCR detected influenza A matrix sequences in 8.5% of samples, H5 in 0.7%, and H7 in 0.6%. Virus isolation yielded 134 influenza A viruses, including N1-N9, H1-H7, H10, and H11 subtypes. Low-pathogenicity H7 subtype was isolated during January, September, and November 2007 and January 2008; low-pathogenicity H5 subtype was isolated during November and December 2007.


Asunto(s)
Anseriformes , Enfermedades de las Aves/virología , Reservorios de Enfermedades/veterinaria , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Animales , Enfermedades de las Aves/epidemiología , Distribución de Chi-Cuadrado , Reservorios de Enfermedades/virología , Femenino , Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Masculino , Prevalencia , ARN Viral/química , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Estaciones del Año , Serotipificación/veterinaria , Texas/epidemiología
16.
Avian Dis ; 54(1 Suppl): 655-9, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20521710

RESUMEN

Historically, virus isolation has been the method of choice for conducting surveillance for avian influenza virus (AIV) in avian species. More recently, the primary screening method has become real-time reverse transcription-polymerase chain reaction (RRT-PCR). We wanted to determine how these two testing methods (virus isolation and RRT-PCR) affected AIV prevalence estimation, particularly in an understudied, low-prevalence region-the waterfowl wintering grounds along the Texas mid-Gulf Coast. Cloacal swabs were collected from hunter-harvested waterfowl and other wetland-associated game birds during four consecutive hunting seasons (2005-2006 through 2008-2009). Overall prevalence by RRT-PCR (5.9%, 6.5%, 11.2%, and 5.5%) was approximately an order of magnitude higher than prevalence by virus isolation (0.5%, 1.3%, 3.9%, and 0.7%) for the four hunting seasons, respectively. Apparent AIV prevalence by virus isolation conducted only on RRT-PCR-positive samples resulted in estimates nearly identical in magnitude to those derived from parallel testing (0.5% vs. 0.6%, 1.3% vs. 1.7%, and 3.9% vs. 4.0% for 2005-2006, 2006-2007, and 2007-2008, respectively). Unlike most reports of seasonal variation in AIV prevalence, we documented differences in prevalence estimates among months by RRT-PCR only during 2008-2009 and by virus isolation only during 2006-2007 and 2007-2008. Our data indicate that screening samples by RRT-PCR followed by virus isolation only on RRT-PCR-positive samples provides a reasonable means to generate prevalence estimates close to the true prevalence as determined by virus isolation. We also confirmed the low prevalence of AIV in waterfowl wintering grounds along the Texas mid-Gulf Coast and demonstrated little variation in prevalence among months during the four hunting seasons sampled.


Asunto(s)
Animales Salvajes , Anseriformes , Gripe Aviar/diagnóstico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Animales , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Prevalencia , Texas/epidemiología , Factores de Tiempo
17.
Conserv Biol ; 24(1): 113-9, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19659684

RESUMEN

Conservationists commonly have framed ecological concerns in economic terms to garner political support for conservation and to increase public interest in preserving global biodiversity. Beginning in the early 1980s, conservation biologists adapted neoliberal economics to reframe ecosystem functions and related biodiversity as ecosystem services to humanity. Despite the economic success of programs such as the Catskill/Delaware watershed management plan in the United States and the creation of global carbon exchanges, today's marketplace often fails to adequately protect biodiversity. We used a Marxist critique to explain one reason for this failure and to suggest a possible, if partial, response. Reframing ecosystem functions as economic services does not address the political problem of commodification. Just as it obscures the labor of human workers, commodification obscures the importance of the biota (ecosystem workers) and related abiotic factors that contribute to ecosystem functions. This erasure of work done by ecosystems impedes public understanding of biodiversity. Odum and Odum's radical suggestion to use the language of ecosystems (i.e., emergy or energy memory) to describe economies, rather than using the language of economics (i.e., services) to describe ecosystems, reverses this erasure of the ecosystem worker. Considering the current dominance of economic forces, however, implementing such solutions would require social changes similar in magnitude to those that occurred during the 1960s. Niklas Luhmann argues that such substantive, yet rapid, social change requires synergy among multiple societal function systems (i.e., economy, education, law, politics, religion, science), rather than reliance on a single social sphere, such as the economy. Explicitly presenting ecosystem services as discreet and incomplete aspects of ecosystem functions not only allows potential economic and environmental benefits associated with ecosystem services, but also enables the social and political changes required to ensure valuation of ecosystem functions and related biodiversity in ways beyond their measurement on an economic scale.


Asunto(s)
Ecosistema , Biodiversidad , Conservación de los Recursos Naturales , Estados Unidos
18.
Conserv Biol ; 23(6): 1458-66, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19508673

RESUMEN

Indigenous people inhabit approximately 85% of areas designated for biodiversity conservation worldwide. They also continue to struggle for recognition and preservation of cultural identities, lifestyles, and livelihoods--a struggle contingent on control and protection of traditional lands and associated natural resources (hereafter, self-determination). Indigenous lands and the biodiversity they support are increasingly threatened because of human population growth and per capita consumption. Application of the Endangered Species Act (ESA) to tribal lands in the United States provides a rich example of the articulation between biodiversity conservation and indigenous peoples' struggle for self-determination. We found a paradoxical relationship whereby tribal governments are simultaneously and contradictory sovereign nations; yet their communities depend on the U.S. government for protection through the federal-trust doctrine. The unique legal status of tribal lands, their importance for conserving federally protected species, and federal environmental regulations' failure to define applicability to tribal lands creates conflict between tribal sovereignty, self-determination, and constitutional authority. We reviewed Secretarial Order 3206, the U.S. policy on "American Indian tribal rights, federal-tribal trust responsibilities, and the ESA," and evaluated how it influences ESA implementation on tribal lands. We found improved biodiversity conservation and tribal self-determination requires revision of the fiduciary relationship between the federal government and the tribes to establish clear, legal definitions regarding land rights, applicability of environmental laws, and financial responsibilities. Such actions will allow provision of adequate funding and training to tribal leaders and resource managers, government agency personnel responsible for biodiversity conservation and land management, and environmental policy makers. Increased capacity, cooperation, and knowledge transfer among tribes and conservationists will improve biodiversity conservation and indigenous self-determination.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Especies en Peligro de Extinción/legislación & jurisprudencia , Humanos , Indígenas Norteamericanos , Estados Unidos
19.
J Wildl Dis ; 44(2): 434-9, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18436675

RESUMEN

The objectives of our study were to determine prevalence of avian influenza viruses (AIV) on wintering grounds on the Texas Gulf Coast, USA, and to compare real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) and virus isolation for detection of AIV in cloacal swabs from wild waterfowl. Cloacal swabs were collected from hunter-harvested waterfowl from November 2005 to January 2006 at four wildlife management areas. Seven AIV were isolated from four species of ducks: Green-winged Teal (Anas crecca) in November; Blue-winged Teal (Anas discors) in November; Mottled Duck (Anas fulvigula) in December, and Northern Shoveler (Anas clypeata) in January. Prevalence of AIV for each of these species during the sampling period was 1.4, 2, 6, and 0.6%, respectively. The AIV subtypes detected were H1N2, H1N4, H4N6, H6N2, and H10N7, all previously reported in North American waterfowl. Our study identified AIV subtypes not previously reported on the Texas Gulf Coast and provides baseline data for a multiyear surveillance project.


Asunto(s)
Patos/virología , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Animales , Animales Salvajes/virología , Aves , Femenino , Masculino , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Estaciones del Año , Vigilancia de Guardia/veterinaria , Especificidad de la Especie , Texas/epidemiología
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