Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Ecol Evol ; 12(10): e9370, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36225830

RESUMEN

The Neosho Bass (Micropterus velox), a former subspecies of the keystone top-predator and globally popular Smallmouth Bass (M. dolomieu), is endemic and narrowly restricted to small, clear streams of the Arkansas River Basin in the Central Interior Highlands (CIH) ecoregion, USA. Previous studies have detected some morphological, genetic, and genomic differentiation between the Neosho and Smallmouth Basses; however, the extent of neutral and adaptive divergence and patterns of intraspecific diversity are poorly understood. Furthermore, lineage diversification has likely been impacted by gene flow in some Neosho populations, which may be due to a combination of natural biogeographic processes and anthropogenic introductions. We assessed: (1) lineage divergence, (2) local directional selection (adaptive divergence), and (3) demographic history among Smallmouth Bass populations in the CIH using population genomic analyses of 50,828 single-nucleotide polymorphisms (SNPs) obtained through ddRAD-seq. Neosho and Smallmouth Bass formed monophyletic clades with 100% bootstrap support. We identified two major lineages within each species. We discovered six Neosho Bass populations (two nonadmixed and four admixed) and three nonadmixed Smallmouth Bass populations. We detected 29 SNPs putatively under directional selection in the Neosho range, suggesting populations may be locally adapted. Two populations were admixed via recent asymmetric secondary contact, perhaps after anthropogenic introduction. Two other populations were likely admixed via combinations of ancient and recent processes. These species comprise independently evolving lineages, some having experienced historical and natural admixture. These results may be critical for management of Neosho Bass as a distinct species and may aid in the conservation of other species with complex biogeographic histories.

2.
J Morphol ; 282(4): 511-519, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33470449

RESUMEN

We provide up-to-date morphological and compositional data on otoliths of the osteoglossomorph Goldeye (Hiodon alosoides). Using computed tomography (CT) X-ray, we documented the location of each of the three pairs of otoliths (lapilli, sagittae, and asterisci) in relation to the swim bladder, which extended forward in close proximity to the sagittae and asterisci. The lappili were the largest otoliths in terms of surface area and volume, but the sagittae were highly modified, appearing spiral in shape when viewed dorsally, with a surface area to volume ratio more than double that of the lapilli. Using scanning electron microscopy, the surface of each otolith was viewable in great detail, and small otoconia (~10.5 µm diameter) were observed on each, but were most numerous on the sagittae. On scanning electron micrographs, the sagittae appeared to be bi-lobed, with asymmetrical lobes each oriented in the same general direction. Using neutron and X-ray diffraction methods, we found three polymorphs of calcium carbonate crystals (aragonite, vaterite, and calcite), sometimes all within the same otolith. However, in general, lapilli and sagittae were composed predominately of aragonite whereas asterisci were composed chiefly of vaterite. With these results, we provide information on a unique species, whose inclusion in future studies would benefit our understanding of fish hearing, fish evolution, and fisheries ecology.


Asunto(s)
Peces/anatomía & histología , Membrana Otolítica/anatomía & histología , Animales , Carbonato de Calcio/química , Membrana Otolítica/diagnóstico por imagen , Membrana Otolítica/ultraestructura , Difracción de Rayos X
3.
Ecol Evol ; 10(2): 705-717, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32015837

RESUMEN

Leveraging existing presence records and geospatial datasets, species distribution modeling has been widely applied to informing species conservation and restoration efforts. Maxent is one of the most popular modeling algorithms, yet recent research has demonstrated Maxent models are vulnerable to prediction errors related to spatial sampling bias and model complexity. Despite elevated rates of biodiversity imperilment in stream ecosystems, the application of Maxent models to stream networks has lagged, as has the availability of tools to address potential sources of error and calculate model evaluation metrics when modeling in nonraster environments (such as stream networks). Herein, we use Maxent and customized R code to estimate the potential distribution of paddlefish (Polyodon spathula) at a stream-segment level within the Arkansas River basin, USA, while accounting for potential spatial sampling bias and model complexity. Filtering the presence data appeared to adequately remove an eastward, large-river sampling bias that was evident within the unfiltered presence dataset. In particular, our novel riverscape filter provided a repeatable means of obtaining a relatively even coverage of presence data among watersheds and streams of varying sizes. The greatest differences in estimated distributions were observed among models constructed with default versus AICC-selected parameterization. Although all models had similarly high performance and evaluation metrics, the AICC-selected models were more inclusive of westward-situated and smaller, headwater streams. Overall, our results solidified the importance of accounting for model complexity and spatial sampling bias in SDMs constructed within stream networks and provided a roadmap for future paddlefish restoration efforts in the study area.

4.
PLoS One ; 14(10): e0224018, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31644599

RESUMEN

Otolith microanalysis is often used to assess population age structure and growth of fishes during their early stages. Shoal Bass Micropterus cataractae is a recently described species of conservation concern and little is known regarding factors affecting their recruitment. In 2004, Georgia Department of Natural Resources (GADNR) and the US National Park Service (NPS) stocked Shoal Bass marked with oxytetracycline (OTC) in the Chattahoochee River near Atlanta, Georgia in an effort to restore this population, creating known-age fish to examine the effect of environment on daily age accuracy. We obtained samples of stocked juvenile (<150 mm) Shoal Bass from standard monitoring that occurred approximately 30-60 days after stocking in the Chattahoochee River to 1) validate daily rings for estimating age, hatch dates, and growth rates for stocked age-0 Shoal Bass, and 2) evaluate the effect of habitat (location) on age bias. Shoal Bass otoliths were examined for OTC marks and daily rings were counted in reference to OTC marks to assess age estimation accuracy. Age estimation accuracy ranged from -2 to -25 days and was influenced by the environment where Shoal Bass were captured, with greater inaccuracy in colder water temperatures. Fish collected from locations with colder temperatures displayed closer spacing of daily rings, potentially leading to greater underestimation of age. Growth rates of stocked Shoal Bass, corrected for age estimation error, ranged from 0.5 mm/day to 0.8 mm/day. This study demonstrates the effect of environmental variability on age inaccuracy and subsequent interpretation of results. Incorporating methods to assess age estimation accuracy is needed to understand interspecific differences in recruitment among black bass species in the variety of natural and human-modified environments they inhabit.


Asunto(s)
Lubina/crecimiento & desarrollo , Ecosistema , Monitoreo del Ambiente , Dinámica Poblacional , Envejecimiento , Animales , Reproducción , Ríos
5.
J Med Entomol ; 56(5): 1395-1403, 2019 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-30950499

RESUMEN

Vector-borne diseases in the United States have recently increased as a result of the changing nature of vectors, hosts, reservoirs, pathogens, and the ecological and environmental conditions. Current information on vector habitats and how mosquito community composition varies across space and time is vital to successful vector-borne disease management. This study characterizes mosquito communities in urban areas of Oklahoma, United States, an ecologically diverse region in the southern Great Plains. Between May and September 2016, 11,996 female mosquitoes of 34 species were collected over 798 trap nights using three different trap types in six Oklahoma cities. The most abundant species trapped were Culex pipiens L. complex (32.4%) and Aedes albopictus (Skuse) (Diptera: Culicidae) (12.0%). Significant differences among mosquito communities were detected using analysis of similarities (ANOSIM) between the early (May-July) and late (August-September) season. Canonical correlation analysis (CCA) further highlighted the cities of Altus and Idabel as relatively unique mosquito communities, mostly due to the presence of Aedes aegypti (L.) and salt-marsh species and absence of Aedes triseriatus (Say) in Altus and an abundance of Ae. albopictus in Idabel. These data underscore the importance of assessing mosquito communities in urban environments found in multiple ecoregions of Oklahoma to allow customized vector management targeting the unique assemblage of species found in each city.


Asunto(s)
Distribución Animal , Biodiversidad , Culicidae/fisiología , Animales , Ciudades , Ecosistema , Femenino , Oklahoma , Estaciones del Año
6.
Conserv Biol ; 32(1): 171-182, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28877382

RESUMEN

Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial-specialist shoal bass (Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non-native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non-native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non-native congeners, wherein non-natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free-flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats.


Asunto(s)
Lubina , Especies Introducidas , Animales , Conservación de los Recursos Naturales , Ríos , Alimentos Marinos
7.
PLoS One ; 12(12): e0189517, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29232384

RESUMEN

Bighead carp (Hypophthalmichthys nobilis) have been introduced throughout Europe, mostly unintentionally, and little attention has been given to their potential for natural reproduction. We investigated the presence of young-of-the-year bighead carp in an irrigation canal network of Northern Italy and the environmental conditions associated with spawning in 2011-2015. The adult bighead carp population of the canal network was composed by large, likely mature, individuals with an average density of 45.2 kg/ha (over 10 fold more than in the main river). The 29 juvenile bighead carp found were 7.4-13.1 cm long (TL) and weighed 9.5-12.7 g. Using otolith-derived spawning dates we estimated that these juveniles were 94-100 days old, placing their fertilization and hatch dates in mid-to-end-June. Using this information in combination with thermal and hydraulic data, we examined the validity of existing models predicting the onset of spawning conditions and the viability of egg pathways to elucidate spawning location of the species. While evidence of reproduction was not found every year, we determined that potentially viable spawning conditions (annual degree-days and temperature thresholds) and pathways of egg drift suitable for hatching are present in short, slow-flowing canals.


Asunto(s)
Carpas/fisiología , Hidrología , Temperatura , Animales , Europa (Continente) , Especies Introducidas , Reproducción
8.
Soc Neurosci ; 9(2): 118-29, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24410372

RESUMEN

Cognitive and biological processes play a role in human aggression. However, relatively little is known about the neural correlates of cognitive processes in aggressive individuals, particularly as they unfold during an aggressive encounter. We investigated whether the P3 event-related potential (ERP) discriminates aggressive versus nonaggressive individuals during a provocative, aggressive encounter. Forty-eight participants (23 men and 25 women) were classified as aggressive or nonaggressive based on self-reported life history of aggression. Aggressive behavior was assessed using a modification of a well-validated laboratory task during which the participant and a fictitious opponent ostensibly delivered and received noise blasts of low, medium, and high intensity. Provocation was manipulated by altering the level of noise set by the opponent. Aggression was defined as the number of high-intensity noise blasts the participant set for the opponent. As predicted, P3 amplitude in response to provocation differed as a function of aggressive history. Nonaggressive individuals showed enhanced P3 when provoked by the opponent relative to low provocation, but this effect was absent in aggressive individuals. The results suggest that aggressive individuals engage fewer neural processing resources in response to provoking social cues, which may reflect aberrant cognitive and emotional processes.


Asunto(s)
Agresión/fisiología , Encéfalo/fisiología , Potenciales Relacionados con Evento P300/fisiología , Adolescente , Adulto , Análisis de Varianza , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Estadística como Asunto , Encuestas y Cuestionarios , Adulto Joven
9.
Rapid Commun Mass Spectrom ; 27(19): 2188-94, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-23996392

RESUMEN

RATIONALE: The otoliths of the inner ear of fishes record the environment of their surrounding water throughout their life. For paddlefish (Polyodon spathula), otoliths have not been routinely used by scientists since their detriments were outlined in the early 1940s. We sought to determine if paddlefish otoliths were useful for resolving elemental information contained within. METHODS: Adult paddlefish were collected from two wild, self-sustaining populations in Oklahoma reservoirs in the Arkansas River basin. Juveniles were obtained from a hatchery in the Red River basin of Oklahoma. Otoliths were removed and laser ablation, inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify eight elements (Li, Mg, Mn, Rb, Sr, Y, Ba, and Pb) along the core and edge portions, which were analyzed for differences between otolith regions and among paddlefish sources. RESULTS: Differences were found among samples for six of the eight elements examined. Otoliths from Red River basin paddlefish born in a hatchery had significantly lower amounts of Mg and Mn, but higher levels of Rb than otoliths from wild paddlefish in the Arkansas River basin. Concentrations of Y, Sr, and Ba were reduced on the edges of adult paddlefish from both reservoirs compared with the cores. CONCLUSIONS: This research shows the utility of using an ICP-MS analysis of paddlefish otoliths. Future research that seeks to determine sources of paddlefish production, such as which reservoir tributaries are most important for reproduction or what proportion of the population is composed of wild versus hatchery-produced individuals, appears promising.


Asunto(s)
Peces , Espectrometría de Masas/métodos , Metales/análisis , Membrana Otolítica/química , Análisis de Varianza , Animales , Animales Salvajes , Ecosistema , Explotaciones Pesqueras , Oklahoma , Reproducibilidad de los Resultados
10.
Brain Stimul ; 6(6): 925-8, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23769413

RESUMEN

BACKGROUND: Daily left prefrontal repetitive transcranial magnetic stimulation (rTMS) over several weeks is an FDA approved treatment for major depression. Although rTMS is generally safe when administered using the FDA guidelines, there are a number of side effects that can make it difficult for patients to complete a course of rTMS. Many patients report that rTMS is painful, although patients appear to accommodate to the initial painfulness. The reduction in pain is hypothesized to be due to prefrontal stimulation and is not solely explained by accommodation to the stimulation. METHODS: In a recent 4 site randomized controlled trial (using an active electrical sham stimulation system) investigating the antidepressant effects of daily left dorsolateral prefrontal rTMS (Optimization of TMS, or OPT-TMS), the procedural painfulness of TMS was assessed before and after each treatment session. Computerized visual analog scale ratings were gathered before and after each TMS session in the OPT-TMS trial. Stimulation was delivered with an iron core figure-8 coil (Neuronetics) with the following parameters: 10 Hz, 120% MT (EMG-defined), 4 s pulse train, 26 s inter-train interval, 3000 pulses per session, one 37.5 min session per day. After each session, procedural pain (pain at the beginning of the TMS session, pain toward the middle, and pain toward then end of the session) ratings were collected at all 4 sites. From the 199 patients randomized, we had usable data from 142 subjects for the initial 15 TMS sessions (double-blind phase) delivered over 3 weeks (142 × 2 × 15 = 4260 rating sessions). RESULTS: The painfulness of real TMS was initially higher than that of the active sham condition. Over the 15 treatment sessions, subjective reports of the painfulness of rTMS (during the beginning, middle and end of the session) decreased significantly 37% from baseline in those receiving active TMS, with no change in painfulness in those receiving sham. This reduction, although greatest in the first few days, continued steadily over the 3 weeks. Overall, there was a decay rate of 1.56 VAS points per session in subjective painfulness of the procedure in those receiving active TMS. DISCUSSION: The procedural pain of left, prefrontal rTMS decreases over time, independently of other emotional changes, and only in those receiving active TMS. These data suggest that actual TMS stimulation of prefrontal cortex maybe related to the reduction in pain, and that it is not a non-specific accommodation to pain. This painfulness reduction softly corresponds with later clinical outcome. Further work is needed to better understand this phenomenon and whether acute within-session or over time painfulness changes might be used as short-term biomarkers of antidepressant response.


Asunto(s)
Trastorno Depresivo Mayor/terapia , Dolor/etiología , Dolor/fisiopatología , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal/efectos adversos , Método Doble Ciego , Humanos , Dimensión del Dolor
11.
J Autism Dev Disord ; 41(2): 248-53, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20521090

RESUMEN

Prepulse inhibition (PPI) may useful for exploring the proposed shared neurobiology between idiopathic autism and autism caused by FXS. We compared PPI in four groups: typically developing controls (n = 18), FXS and autism (FXS+A; n = 15), FXS without autism spectrum disorder (FXS-A; n = 17), and idiopathic autism (IA; n = 15). Relative to controls, the FXS+A (p < 0.002) and FXS-A (p < 0.003) groups had impaired PPI. The FXS+A (p < 0.01) and FXS-A (p < 0.03) groups had lower PPI than the IA group. Prolonged startle latency was seen in the IA group. The differing PPI profiles seen in the FXS+A and IA indicates these groups may not share a common neurobiological abnormality of sensorimotor gating.


Asunto(s)
Trastorno Autístico/fisiopatología , Síndrome del Cromosoma X Frágil/fisiopatología , Filtrado Sensorial , Adolescente , Análisis de Varianza , Trastorno Autístico/complicaciones , Niño , Femenino , Síndrome del Cromosoma X Frágil/complicaciones , Síndrome del Cromosoma X Frágil/psicología , Humanos , Masculino , Tiempo de Reacción/fisiología , Reflejo de Sobresalto/fisiología , Filtrado Sensorial/fisiología , Estadísticas no Paramétricas , Adulto Joven
12.
MGMA Connex ; 9(9): 51-5, 1, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19886086

RESUMEN

A task-reorganization study in an orthopedic practice shows how a four-step process can allow you to increase patient throughput and decrease waiting time.


Asunto(s)
Eficiencia Organizacional , Admisión y Programación de Personal/organización & administración , Administración de la Práctica Médica/organización & administración , Atención al Paciente , Factores de Tiempo
13.
Am J Med Genet B Neuropsychiatr Genet ; 150B(4): 545-53, 2009 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-18785205

RESUMEN

Pharmacological rescue of behavioral, cognitive and synaptic abnormalities in the animal models of fragile X syndrome (FXS) has prompted the initiation of clinical trials of targeted treatments in humans with this condition. Objective, well-validated outcome measures that are reflective of FXS deficits and can be modeled similarly in animal and human studies are urgently needed. A protocol measuring prepulse inhibition (PPI) of the startle reflex, including measures of test-retest stability, was evaluated in 61 individuals with the fragile X full mutation (40 males and 21 females; 19.18 +/- 7.18 years) and 63 age-matched normal controls (35 males and 28 females; 20.83 +/- 6.96 years) across two laboratory sites with identical equipment and protocols. Relative to controls, the fragile X group had PPI impairment of 26%, 22%, and 28% for 60, 120, and 240 ms prepulse interval trial types, respectively, P = 0.000002. PPI test-retest reliability in 29 of the participants was excellent for the 120 ms prepulse interval trials (intraclass correlations: FXS, 0.85; controls, 0.88, 0.89 overall). This study demonstrates the feasibility and reliability of PPI measurement in a developmentally disabled population and highlights its potential as an outcome measure to test the efficacy of targeted neurotherapeutic agents.


Asunto(s)
Síndrome del Cromosoma X Frágil/fisiopatología , Reflejo de Sobresalto , Filtrado Sensorial , Estimulación Acústica , Adolescente , Adulto , Trastorno por Déficit de Atención con Hiperactividad/etiología , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Estudios de Casos y Controles , Ensayos Clínicos como Asunto , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/fisiopatología , Femenino , Síndrome del Cromosoma X Frágil/genética , Síndrome del Cromosoma X Frágil/terapia , Humanos , Masculino , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Reproducibilidad de los Resultados , Adulto Joven
14.
Brain Res ; 1251: 213-22, 2009 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-19046953

RESUMEN

OBJECTIVE: The neurophysiological correlates of mental activity and awareness are important to define, as they permit the objective study of these psychological phenomena. METHODS: In a choice reaction task, subjects were asked to respond to tone pips by extending their fingers and to make non-semantic vocalizations as soon as they became aware of any errors. RESULTS: In motor response-synchronized averages of instances in which subjects were aware of making errors, a biphasic cerebral potential occurred over the frontocentral scalp region 170 ms after the incorrect motor response and about 500 ms prior to any vocalization. It occurred 100 ms after the so-called error negativity (Ne), from which it was therefore distinguished. CONCLUSION: The recording of such activity may therefore provide an electrophysiological signature of perceptual awareness related to making errors. SIGNIFICANCE: Recording this potential may facilitate the objective study of awareness to errors in other experimental contexts.


Asunto(s)
Concienciación/fisiología , Corteza Cerebral/fisiología , Cognición/fisiología , Potenciales Evocados/fisiología , Desempeño Psicomotor/fisiología , Estimulación Acústica , Adulto , Atención/fisiología , Mapeo Encefálico , Corteza Cerebral/anatomía & histología , Conducta de Elección/fisiología , Aprendizaje Discriminativo/fisiología , Electroencefalografía , Femenino , Dedos/fisiología , Humanos , Masculino , Actividad Motora/fisiología , Movimiento/fisiología , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Reconocimiento en Psicología/fisiología , Conducta Verbal/fisiología , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...